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Tuyisingize, Deogratias. "Terrestrial small mammal community composition in the Volcanoes National Park, Rwanda." Master's thesis, University of Cape Town, 2010. http://hdl.handle.net/11427/4763.
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Bussière, Elsa Marion Sylvie. "Camera traps as sensor networks for space-time exploration of terrestrial mammal communities." Doctoral thesis, Faculty of Science, 2018. http://hdl.handle.net/11427/30184.
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Most of the conservation issues which ecologists are called on to help resolve are essentially about ecological communities. Camera trapping technology has led to a surge in the collection of large ecological datasets, which provides an unmissable opportunity to attain deeper knowledge of animal community assembly and structure. Using extensive camera trap data, this thesis examines whether camera traps can be used as sensor networks for a space-time exploration of the terrestrial mammal community that occurs in the Little Karoo of South Africa. In Chapter 1, the species-habitat relationship along a ruggedness gradient was studied. Using resource selection functions and multivariate statistics, this chapter showed that the strength of affinities, which mammals developed with specific terrain roughness, varied among species. It also enabled the recognition of subtle and continuous nuances in the spectrum of habitat preferences, providing a novel tool to explore the forces driving species coexistence in local animal communities. The theme of Chapter 2 was to consider patterns of seasonal occurrence within species circadian rhythms. Using kernel density functions with descriptive and multivariate statistics, this chapter showed that most mammal species responded to the ecological variability brought about by seasonality by adjusting their diel activity rhythms between winter and summer, resulting in a reduction of time exposure to a physiologically stressful environment caused by high temperatures in summer. It also highlighted that while some shifts only result from photoperiodism alignment, most are driven by other factors too. Chapter 3 examined temporal-partitioning as a mechanism driving sympatry. Using kernel density functions and mutivariate statistical analyses, this chapter enabled subtle nuances in the spectrum of diel activity rhythms to be visualised, highlighting the variety of temporal niche breadths and of activity onset/offset timings, which allowed diel activity rhythms to diversify and the mammal community to partition the temporal resources. Finally, in Chapter 4, topics dealing with leopard habitat preferences and leopard population density were explored. Using spatially explicit capture-recapture models, this chapter showed that leopard density remained low but varied with topographic relief; it increased with ruggedness of the terrain up to an optimum, and followed a reversed trend as the terrain roughness kept increasing. The population was composed of two groups of individuals with significantly different home range sizes, potentially explained by gender duality in movement. The chapter provided leopard density estimates ranging from 0.49 to 0.82 individual per 100 km2 . Local communities, such as that of the mammal species of the Little Karoo, are neither closed nor isolated. Therefore, it would be insightful if future studies were to embrace the metacommunity concept and explain these patterns of species distribution, abundance and interaction at multiple scales of spatio-temporal organisation.
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Lyon, Rebecca J. "Occupancy of Terrestrial Mammal Species of the Madeira-Purus Interfluvium in Amazonas, Brazil." OpenSIUC, 2017. https://opensiuc.lib.siu.edu/theses/2121.
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The Amazon represents more than half of the surviving tropical forest on Earth. However, despite its vast size and diversity, habitat loss is an increasing threat due to the growth of economic activities and infrastructure projects. Carnivores play an important role in reducing herbivore numbers through predation, thereby reducing the risk of over browsing and are particularly susceptible to habitat loss and fragmentation due to their large area requirements, low densities, and slow population growth. Altering herbivore communities via a change in carnivore density and habitat loss may change plant diversity by altering seed dispersal, and seed and seedling survival. The Madeira-Purus interfluvial plain in Brazil is a pristine and yet understudied part of the Amazon. I studied environmental factors affecting occupancy and detection of carnivores and herbivores in the Madeira-Purus interfluvial plain Amazonas state, Brazil. During 2010-12 remote cameras were used to investigate patterns of site occupancy and detection probabilities, as affected by habitat and anthropogenic influences, for several terrestrial mammal groups. Site occupancy and detection varied for all species groups across land protections types. Medium felids and peccaries showed a sharp decline in occupancy from unprotected lands to state-protected sites with the highest occupancy on the federally-protected site. Brocket deer increased in occupancy from unprotected to state-protected lands, and from state-protected to federally-protected lands. Large felid occupancy, however, was exactly the opposite, with the lowest occupancy at the federally-protected site. Species richness at camera sites was the most important covariate, positively influencing occupancy in all species groups. This helps inform wildlife management by providing suggestions to improve future occupancy studies and support for maintaining protected areas for the persistence of viable mammal populations. I found occupancy of many species groups (i.e. peccaries, medium felids and medium rodents) were lowest on state-protected land. Species richness was also lowest on state-protected land, implying a depletion of herbivore and carnivore species in that area, which may be due to local foraging and hunting of forest resources by humans. I recommend stricter laws and enforcement to limit the harvest of forest fruits and nuts and illegal hunting. Repaving local highways will likely increase human influence in these areas and increase pressure on forest resources.
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Tsubamoto, Takehisa. "The Pondaung mammal fauna : an analysis of a terrestrial mammal fauna in the latest middle Eocene of central Myanmar (Southeast Asia)." 京都大学 (Kyoto University), 2001. http://hdl.handle.net/2433/150841.
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Boyles, Esmarie. "Mammalian carnivores as bioindicators to evaluate the exposure and bioaccumulation of organic contaminants in terrestrial ecosystems." OpenSIUC, 2017. https://opensiuc.lib.siu.edu/dissertations/1341.
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To address my first objective, I opportunistically collected road-killed bobcats (n=44) throughout Illinois during 2013-2014, and analyzed their liver tissue for the presence of PCBs, PBDEs, and various other alternative halogenated flame retardants. Concentrations of ∑PCBs ranged from 76.4 ng/g lw to 3782 ng/g lw (median 562.97 ng/g lw). Male bobcats had significantly higher concentrations of PCBs than females (p = 0.04). Concentrations of ∑PBDEs (including all detectable PBDE congeners) ranged from 8.3 to 1920 ng/g lipid weight (median: 50.3 ng/g lw). Among the alternative flame retardants screened, Dechloranes (including anti- and syn-Dechlorane Plus and Dechlorane-602, 603, and 604), tetrabromo-o-chlorotoluene (TBCT), and hexabromocyclododecane (HBCD) were also detected frequently, with median concentrations of 28.7, 5.2, and 11.8 ng/g lw, respectively. Dechlorane analogue compositions in bobcats were different from that reported in other studies, suggesting species- or analogue-dependent bioaccumulation, biomagnification, or metabolism of Dechlorane chemicals in different food webs. My findings, along with previously reported food web models, suggest Dechloranes may possess substantial bioaccumulation and biomagnification potencies in terrestrial mammalian food webs. Thus, attention should be given to these highly bioavailable flame retardants in future environmental biomonitoring and risk assessments in a post-PBDE era. To address my second objective I collected raccoons (n=32) from various sites across Illinois and Missouri during 2013-2015. Liver tissues were analyzed for the presence of PBDEs and Dechloranes. ∑PBDE concentrations ranged from 19.1 ng/g lw to 2124 ng/g lw (median = 98.0 ng/g lw) and did not differ between gender or age of raccoon. Although nonsignificant (p=0.06), adult raccoons appeared to have greater PBDE concentration loads compared to juveniles. These nonsignificant differences are likely due to large variation in contaminant concentrations, possibly reflecting differences in individual raccoon diet and behavior. This is the first study reporting bioaccumulation of halogenated flame retardants in a wild felid in North America, and also the first report of PBDE accumulation in North American raccoons. The wide detection of Dechloranes, HBCD and TBCT in bobcats suggests a broad exposure of these alternative flame retardants in terrestrial apex predators in terrestrial ecosystems. The comparatively high levels of PBDEs in raccoons also suggest that biota in terrestrial habitats are still widely exposed to and susceptible to the bioaccumulation of these flame retardants.
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Watanabe, Brett Kaoru. "Differences in Basal Metabolic Rates, Heart Masses, and Hematocrits of Bats, Terrestrial Mammals, and Birds." Scholarship @ Claremont, 2014. http://scholarship.claremont.edu/cmc_theses/836.
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Bats are the only mammals capable of powered flight. In flight, bats consume up to 20 times more oxygen per hour than under basal conditions. This is twice the increase reported for running mammals of the same body sizes. Birds are the only other group of vertebrate capable of powered flight. By plotting morphological and physiological parameters against body mass for bats, terrestrial mammals, and birds, we can observe to what extent these parameters permit high rates of oxygen delivery necessary for flight.
In this study we analyzed basal metabolic rate, heart mass, and hematocrit, and compared how differently they scale in the afore-mentioned groups. We found that larger heart masses are associated with the ability to fly; hematocrit values for birds change markedly with body size, while those for mammals and bats are nearly independent of body size; and that BMR scales differently in all three groups.
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Walker, Kevin R. "Climatic Dependence of Terrestrial Species Assemblage Structure." Thèse, Université d'Ottawa / University of Ottawa, 2013. http://hdl.handle.net/10393/23697.
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An important goal of ecological studies is to identify and explain patterns or variation in species assemblages. Ecologists have discovered that global variation in the number of species in an assemblage relates strongly to climate, area, and topographic variability in terrestrial environments. Is the same true for other characteristics of species assemblages?
The focus of this thesis is to determine whether species assemblage structure, defined primarily as the body mass frequency distributions and species abundance distributions relate in convergent ways to a set of a few environmental variables across broad spatial scales.
First, I found that for mammals and trees most of their geographic variation across North and South America in assemblage structure is statistically related to temperature, precipitation, and habitat heterogeneity (e.g. different vegetation types) in convergent ways.
I then examined bird assemblages across islands and continents. Despite the evolutionary and ecological differences between island and continental assemblages, I found that much of the variation in bird assemblage structure depends on temperature, precipitation, land area, and island isolation in congruent patterns in continent and island bird assemblages.
Frank Preston modeled species richness based on the total number of individuals and the number of individuals of the rarest species. Building on Preston’s model, Chapter 2 hypothesized that gradients of diversity correlate with gradients in the number of individuals of the rarest species, which in turn are driven by gradients in temperature and precipitation. This hypothesis assumes that species abundance distributions relate to temperature and precipitation in similar ways anywhere in the world. I found that both the number of individuals of the rarest species (m) and the proportion of species represented by a single individual in samples of species assemblages (Φ) were strongly related to climate. Moreover, global variation in species richness was more strongly related to these measures of rarity than to climate. I propose that variation in the shape of the log-normal species abundance distribution is responsible for global gradients of species richness: rare species (reflected in m and Φ) persist better in benign climates.
Even though body mass frequency distributions of assemblages show convergent patterns in relation to a set of a few environmental variables, the question remains as to what processes are responsible for creating the geographical variation in the body-size distribution of species. Several mechanisms (e.g. heat conservation and resource availability hypotheses) have been proposed to explain this variation. Chapter 5 tested and found no empirical support for the predictions derived from each of these mechanisms; I showed that species of all sizes occur across the entire temperature gradient.
In conclusion, assemblage structure among various taxonomic groups across broad spatial scales relate in similar ways to a set of a few environmental variables, primarily mean annual temperature and mean annual precipitation. While the exact mechanisms are still unknown, I hypothesize several to explain the patterns of convergent assembly.
Résumé
Un but important de l'écologie est d'identifier et d'expliquer la variation de premier ordre dans les caractéristiques des assemblages d'espèces. Un des patrons ayant déjà été identifié par les écologistes, c'est que la variation mondiale de la richesse en espèces est liée à la variation du climat, de l'aire et de la topographie. Est-ce que d'autres caractéristiques des assemblages d'espèces peuvent être reliées à ces mêmes variables?
Le but de cette thèse est de déterminer si la structure des assemblages d'espèces, ici définie comme la distribution des fréquences de masse corporelle ainsi que la distribution d'abondances des espèces, est reliée de manière convergente à un petit ensemble de variables environnementales, et ce, partout dans le monde.
D'abord, j'ai déterminé que, pour les mammifères et les arbres, la majorité de la variation géographique dans la structure des assemblages d'espèces est reliée statistiquement à température, précipitation, et l’hétérogénéité du couvert végétal , et ce, de manière convergente pour l'Amérique du Nord et du Sud.
Je me suis ensuite penché sur l'assemblage des oiseaux sur les îles et les continents. Malgré les larges différences évolutives et écologiques qui distinguent les îles des continents, je démontre que la majorité de la variation dans la structure des assemblages d'oiseaux dépend de la température, la précipitation, la superficie et l’isolation de façon congruente sur les îles et les continents.
Frank Preston a modélisé la richesse en espèces d'une localité, basée sur le nombre total d'individus ainsi que le nombre d'individus de l’espèce la plus rare. En s'appuyant sur les modèles de Preston, Chapître 3 propose une nouvelle hypothèse voulant que les gradients de diversité dépendent des gradients du nombre d'individus de l’espèce la plus rare. Celle-ci dépend des gradients de température et de précipitation. Cette hypothèse repose sur le postulat que la distribution d’abondances des espèces dépend de la température et la précipitation, et ce, de la même manière n’importe où au monde. J’ai mis en évidence que le nombre d’individus de l’espèce la plus rare (m), ainsi que la proportion d’espèces représentées par un individu unique () dans des échantillons locaux étaient fortement reliés au climat. D’ailleurs, la variation globale de la richesse en espèces était plus fortement reliée à ces indices de rareté qu’au climat. Je propose que la variation dans la forme de la distribution log-normale d’abondances d’individus soit responsable des gradients mondiaux de richesse en espèces. En d’autres mots, les espèces rares (indiquées par m et ) persistent mieux dans des climats bénins.
Malgré que la distribution des fréquences de masse corporelle des assemblages d'espèces soit liée de manière convergente à seulement quelques variables environnementales, la question demeure à savoir quels processus sont responsables des gradients géographiques de variation en masse corporelle des espèces. Plusieurs mécanismes ont été proposés pour expliquer cette variation. Dans Chapitre 5, j'ai testé les prédictions dérivées de chacun de ces mécanismes sans trouver de support empirique pour aucun. Je démontre aussi que des espèces de toutes tailles se retrouvent sur le gradient de température en entier.
En conclusion, la structure des assemblages d'espèces, pour différents groupes taxonomiques et à travers le monde, est liée de façon similaire à un petit nombre de variables environnementales. Bien que les mécanismes soient encore inconnus, j'en propose plusieurs pouvant expliquer ces patrons d'assemblages convergents.
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Cavalcante, Santos Cyntia. "Terrestrial herbivorous mammals in a mosaic of Cerrado, Atlantic Forest, and land-use changes." Thesis, Angers, 2019. http://www.theses.fr/2019ANGE0057.
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Les « hotspots » de la biodiversité du Cerrado et des forêts atlantiques ont souffert des changements rapides d’utilisation du sol au cours des cinq dernières décennies, résultant en une fragmentation de l’habitat, l’invasion d’espèces exotiques et la perte de biodiversité. Les mammifères herbivores sont une communauté clé pour étudier les impacts des changements d’utilisation des sols, car ils sont directement influencés par la structure du paysage. Premièrement, nous avons examiné des articles publiés entre 2002 et 2018 sur les mammifères terrestres dans des contextes de changement d’utilisation du sol dans le Cerrado brésilien. Nous avons constaté que les réactions négatives des mammifères aux changements d'utilisation du sol étaient associées à l'agriculture, à l'élevage, aux routes et aux zones urbaines. De plus, nous identifions de grandes lacunes de connaissances. Deuxièmement, nous avons collecté des données sur la communauté de mammifères herbivores à travers les gradients de changements d'utilisation du sol sur le plateau de Bodoquena au Brésil entre février 2016 et décembre 2017. Nous analysions comment et à quelle échelle trois métriques du paysage (pourcentage de couverture forestière, densité de parcelles et densité de lisières) affectent l'occurrence de quatre espèces herbivores (Dasyprocta azarae, Pecari tajacu, Mazama gouazoubira et Tapirus terrestris). Nous avons trouvé des différences dans les échelles auxquelles les espèces ont répondu à différentes mesures du paysage. Enfin, nous avons modélisé l'occupation de 23 mammifères herbivores dans le paysage du plateau de Bodoquena. Le modèle d'occupation en fonction du couvert forestier a montré des réactions idiosyncratiques par espèce aux changements d'utilisation du sol. Par conséquent, nous recommandons des stratégies différentes et complémentaires, notamment la restauration de l'habitat, pour la protection et gestion des mammifères herbivores au plateau de Bodoquena<br>The Cerrado and Atlantic forest biodiversity hotspots have been experiencing rapid land-use changes in the last five decades resulting in habitat fragmentation, invasion of exotic species and biodiversity loss. Herbivore mammals are a key community to investigate the impacts of land-use changes on biodiversity, because they are directly influenced by the landscape structure. In a first step, we reviewed articles published between 2002 and 2018 about terrestrial mammals in contexts of land-use change in the Brazilian Cerrado. We found that negative responses of mammals to land-use changes were mainly associated with agriculture, livestock, roads and urban areas. Moreover, we identified big knowledge gaps, for example in the coverage of research areas or species. Secondly, we collected data on the community of herbivore mammals across gradients of land-use changes in the Bodoquena Plateau in Brazil between February 2016 and December 2017. We analyzed how and on which scale three landscape metrics (percentage of forest cover, patch density and edge density) affect the occurrence of four herbivore species (Dasyprocta azarae, Pecari tajacu, Mazama gouazoubira and Tapirus terrestris). We found differences in the scales at which the species responded to different landscape metrics. Finally, we modeled the occupancy of 23 herbivore mammals in the landscape of the Bodoquena Plateau. The pattern of occupancy as a function of forest cover percentage showed idiosyncratic responses per species to land-use changes. Therefore, we recommend different and complementary strategies including habitat restoration for conservation and management of herbivore mammals in the Bodoquena Plateau
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Mouta, Catarina Feliciano. "Spatiotemporal patterns of culvert use by terrestrial Mediterranean mammals." Master's thesis, Universidade de Évora, 2020. http://hdl.handle.net/10174/30088.
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Culvert flooding jeopardizes their use as safe crossing locations for animals, especially in locations with significative precipitation. The installation of elevated dry ledges inside culverts has been studied as a solution, although it is still not certain how effective they are. In order to tackle this problem, we tried to understand the under-road crossing patterns of mammals in culverts with and without ledges. We got enough data for six species, which showed carnivores had distinct preferences regarding culvert design and that culvert use was also dependent on environmental features surrounding it. Structure openness, distance to the nearest passage, water inside the culvert and season were the variables that most influenced crossing probabilities. Responses to these variables varied among species, highlighting the need for different type of structures that can fulfil each species’ necessities; RESUMO:
“Padrões espaciotemporais de uso de passagens hidráulicas por mamíferos mediterrânicos terrestres”
A inundação das passagens hidráulicas põe em risco o seu uso como locais de atravessamento seguro para os animais, especialmente em locais onde a precipitação é significativa. A instalação de passadiços elevados tem sido usada como solução, no entanto ainda não é conhecida com rigor a sua eficiência. Para tentar resolver este problema, estudámos os padrões de atravessamento por mamíferos em passagens com e sem passadiços. Apesar de só terem sido reunidos dados suficientes para seis espécies, determinámos que estes carnívoros têm preferências distintas quanto à estrutura da passagem e que o ambiente circundante também é um factor relevante no seu uso. A abertura das passagens, a distância entre elas, a quantidade de água e a estação foram as variáveis que mais influenciaram o uso. As respostas variaram entre espécies, mostrando a urgência de estruturas polivalentes que colmatem as necessidades de cada uma.
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Koep, Karin Sarah Coles. "Production of salami from meat of aquatic and terrestrial mammals." Thesis, Link to the online version, 2005. http://hdl.handle.net/10019/1073.
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Tognelli, Marcelo Fabio. "Patterns of species richness and conservation of South American terrestrial mammals /." For electronic version search Digital dissertations database. Restricted to UC campuses. Access is free to UC campus dissertations, 2003. http://uclibs.org/PID/11984.
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Erry, Berenice Veronica. "Transfer of arsenic through terrestrial food chains." Thesis, University of Exeter, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.302537.
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Holland, Angela. "BRIDGING AQUATIC AND TERRESTRIAL ECOSYSTEMS: ECOLOGY OF SEMI-AQUATIC MAMMALS IN SOUTHERN ILLINOIS." OpenSIUC, 2016. https://opensiuc.lib.siu.edu/dissertations/1269.
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Mammals in freshwater aquatic systems play important roles as ecosystem engineers, trophic transfer agents, and apex predators, thus acting as indicators of freshwater ecosystem function. Watersheds inhabited by semi-aquatic mammals have increased links between adjacent terrestrial and aquatic ecosystems compared to watersheds where they are not present. Semi-aquatic mammals not only exert top-down influences on streams, but are affected by bottom-up forces from the riparian system itself. The goal of this study was to identify variables that correlate with the presence of beaver (Castor canadensis), muskrat (Ondatra zibethicus), mink (Neovison vison), and river otter (Lontra canadensis), including their interactions, resulting in a better understanding of the areas where these semi-aquatic mammals occur and their effects on the riparian system. The objectives of this study were (1) to identify variables related to the probability of detection, initial occupancy, colonization, and extinction of the 4 semi-aquatic mammals in southern Illinois; and (2) to test if the reintroduction of river otter has changed stream food webs. To address my first objective, I sampled 120 bridge sites in 2 periods (winter: Jan-Feb; and spring: Mar-Apr) during 2012–2014 in 11 major watersheds in the southern third of Illinois (44,526 km2) to estimate multi-season occupancy. Each survey unit was a 400-m stream segment visited twice by 2 observers for a total of 4 observations per site per period. Observers recorded all mammal signs found, including sign species and type. Sites were Intensive Basin Survey Sites sampled by Illinois Department of Natural Resources (IDNR) and Illinois Environmental Protection Agency (IEPA), allowing data collected by the state to be available for explanatory variables for mammal occupancy. Data collected by the Illinois Natural History Survey (INHS) also were available for a subset of sites. I collected local- and landscape-scale habitat and weather variables for each site. I developed hypotheses regarding occupancy of sites based on land-cover, human disturbance, and stream attributes for each species. I developed additional hypotheses regarding prey availability and water quality for river otter and mink. Sites used in each analysis were dependent on data available to address the hypotheses of interest. Beaver and muskrat were present at ≥100 of 103 sites for ≥1 observation. Naïve occupancy was high (≥82%) every year for both species. Detection probabilities for beaver and muskrat were best predicted by survey period. Beaver detection remained fairly constant across survey periods except for a decrease in winter 2014, whereas muskrat detection was generally lower during winter and higher during spring. Beaver were more likely to occupy larger streams than smaller streams during the initial survey period. Sites that lacked a dominant land-cover had a lower probability of beaver colonization than sites dominated by agriculture or woody vegetation at the landscape scale. In addition, the probability that a site would be colonized by beaver during the study increased with availability of water within 1 km of the surveyed segment, increased stream density, sites at larger streams, and river otter presence during the previous period. The probability of site extinction decreased as stream size, stream density within 1 km, and water availability within 500 m of the survey segment increased. Occupancy of muskrat during the initial survey period was negatively predicted by % forest in the 1-km riparian area, channel incision, and amount mercury in the sediment. Colonization by muskrats was lower during the long spring to winter intervals than the short winter to spring intervals, and was positively related to the amount of organic carbon in the sediment. The probability of site extinction by muskrat increased with increasing % forest within the riparian area around the stream segment, decreasing 1-km stream density, and when land-cover within 1 km of sites was dominated by agriculture or woody vegetation. Multi-season occupancy of river otter and mink were assessed in 2 separate analyses that used either land-cover and management variables or prey availability and riparian community composition, respectively. In the first analysis, river otter and mink were present at ≥84 of 103 sites. Naïve occupancy was higher every year for mink (≥88.3%) than for river otter (≥55.3%). Detection of river otter and mink in the first analysis increased as substrate availability increased. Occupancy of river otter during the initial survey period was predicted by large stream size, low % developed area within 250 m of the surveyed segment, and proximity to nearest river otter reintroduction point. Probability of colonization by river otter varied by survey period and was higher at sites with larger streams, higher stream density, lower % developed area, and within a known river otter population area. Site extinction by river otter in the first analysis varied by survey period and was linked to increased organic carbon in the sediment, and decreased road density within 1 km of the surveyed segment. River otter harvest was not found to affect site colonization or extinction. Mink occupancy during the initial period was negatively associated with water availability within 100 m of the survey segment. Site colonization by mink varied by month and increased with increasing developed area within 100 m of the surveyed segment, increasing channel incision, and decreasing rainfall. Probability of site extinction for mink increased as stream size and developed area within 500 m of the surveyed segment increased, and when woody vegetation was the dominant land-cover type within 1 km of the surveyed segment. The second analysis of multi-season occupancy of river otter and mink used 77 sites, 81.8% of which had ≥1 river otter detection in the study and 98.7% of which had ≥1 mink detection. Naïve occupancy differed between years but gradually increased for river otter and remained high (≥93.5%) for mink. Increasing substrate availability increased the probability of river otter detection, whereas mink detection varied by survey period. Occupancy during the initial survey period was higher in sites closer to the reintroduction points for river otter. Probability of colonization of river otter was positively associated with macroinvertebrate IBI and fish species richness, sites with high fish species richness of fish families preferred by river otter also had reduced otter extinction probability. No tested variables predicted initial occupancy for mink, but mink were more likely to colonize sites with increased fish richness and when muskrat were present during the previous period. Mink had decreased probability of extinction in sites with increasing mussel community index. My results indicate that semi-aquatic mammals in Illinois were affected by a riparian habitat, water availability, and stream community variables at both the landscape and local scale. I found high occupancy of mink, beaver, and muskrat across the entire landscape of southern Illinois, and my results suggest that the geographic range of river otter continues to expand. Relationships of occupancy of these semi-aquatic mammals to measurements of urban areas and human disturbance were not consistent across all species. Mink and river otter occupancy were both predicted by aspects of prey availability, indicating the importance of predator-prey relationships in occupancy dynamics of riparian predators. Hypotheses regarding predator pressure and changes in environmental variables were used to test the effects of river otter reintroduction on stream communities. For this objective, I used structural equation models. I compared fish and macroinvertebrate communities from before (1982-1995) and after (2005-2013) reintroduction of river otter, which occurred in 1994–1996. Fish and macroinvertebrate community data for 35 sites located throughout 6 major watersheds in southern Illinois (25,550 km2) were obtained from state agencies. Changes in stream communities were evaluated using 4 metrics (species richness, species dominance, skewness in size distribution of prey, and proportion of individuals in the size class preferred by river otter). Neither the inclusion of river otter site use nor change in stream quality, measured by change in % forest, improved models over the simple model which only included fish and macroinvertebrate communities. Overall, I found no evidence that river otter presence or change in forest cover affected stream fish and macroinvertebrate communities.
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Murray, Bryan David. "Risk-Sensitive Foraging Facilitates Species-Level Trophic Cascades Among Terrestrial Mammals: A Meta-Analysis." Wright State University / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=wright1253037872.
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O'Brien, Carrie J. "Terrestrial Small Mammals from the Gamba Complex in Gabon: Distribution Patterns and Landscape Influences." DigitalCommons@USU, 2009. https://digitalcommons.usu.edu/etd/353.
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The small mammal communities of central Africa are not well understood, and the southwestern section of Gabon has not been previously surveyed except for some recent work in Monts Doudou. At five sites within the Gamba Complex we set out to 1) document the species of terrestrial rodents (Muridae) and shrews (Soricidae) weighing less than 100 g, 2) compare the community composition between inland and coastal sites, and 3) evaluate our sampling protocols. Using a combination of pitfall lines, Sherman live traps, and snap traps we captured 721 individuals of 12 rodent and 10 shrew species in 15,792 trap-nights. The rodent community was dominated by Hylomyscus stella and the shrew community by Sylvisorex johnstoni, in agreement with nearby studies. The coastal sites were less diverse with 3 rodent species and 1 shrew species only found at inland sites. The inland Rabi site had the most diverse small mammal community due to 2 species captured in secondary forests and fields near the oil facility. Our use of pitfalls was essential to our capture of shrews, and our protocol of switching from live to snap traps midway through the trapping period resulted in more species than expected.
The ecological factors influencing distribution patterns of small mammals in central Africa is not well understood. We evaluated the role of disturbance at paired inland and coastal sites using landscape variables generated from satellite imagery. Regression analyses revealed that while the amount of forest present at a site was strongly correlated with rodent richness (F = 16.437; df = 1; p = 0.001), shrew richness was negatively correlated with the amount of roads (partial F = 12.232; df = 1; p = 0.007) and rainfall (partial F = 6.035; df = 1; p = 0.036) and positively with elevation (partial F = 6.832; df = 1; p = 0.028). Our results suggest that while disturbance at Rabi has created additional habitats for rodents, the loss of specialist rodents from coastal sites reflects their inability to tolerate the edge-affected, fragmented, and less diverse forests in that region.
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Moran, Meghan M. "MORPHOLOGICAL PATTERN AND MOLECULAR SIGNALING DURING INTERVERTEBRAL AND EPIPHYSEAL FUSION IN CETACEANS AND TERRESTRIAL MAMMALS." Kent State University / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=kent1343050216.
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Forsey, Elizabeth Susan. "Mammalian abundance in riparian and adjacent terrestrial habitats prior to and immediately following forest harvesting in the Copper Lake watershed, Newfoundland." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape10/PQDD_0005/MQ42379.pdf.
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Pretzlaw, Troy. "Pattern, composition and resource selection of terrestrial vertebrates across the Yukon forest to tundra transition." Thesis, McGill University, 2006. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=101166.
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Ecotones are gradients of change between expanses of similar species composition. These regions often mark co-occurring range limits for several species, and thus are ideal for elucidating ecological and biogeographical phenomena. The forest to tundra transition (FTT) is one of the world's most prominent ecotones, but remains poorly studied especially with regard to vertebrate species occurrence. Vertebrate diversity, ecological structure and resource selection were characterized across the Yukon FTT using diversity metrics, ordination, hierarchical clustering, and resource modeling. The FTT represents an abrupt drop in vertebrate species richness within the more gradual, continental scale diversity gradient. Despite the patchiness and complexity in vegetative structure over this ecotone, the terrestrial vertebrate community is divisible into boreal, taiga, and tundra compartments. Most species conform to resource associations reported closer to the core of their range, generating remarkably consistent habitat and species associations despite a complex patchwork of contrasting habitat types.
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Gustafson, Gregory Gene. "Effects of Management Practices on Terrestrial Vertebrate Diversity and Abundance in an Oak Savanna Ecosystem." Bowling Green State University / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1523016712853504.
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Kuprewicz, Erin Kathleen. "The Effects of Large Terrestrial Mammals on Seed Fates, Hoarding, and Seedling Survival in a Costa Rican Rain Forest." Scholarly Repository, 2010. http://scholarlyrepository.miami.edu/oa_dissertations/391.
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Terrestrial mammals affect numerous aspects of plant demography, colonization, and community structure in Neotropical forests. Granivorous mammals destroy seeds via seed predation and seedlings through herbivory, negatively affecting plant fitness. Mammals can also positively affect plants by dispersing or hoarding seeds. Seed fate outcomes are contingent on the interaction between mammal seed handling strategies and the intrinsic anti-predation defenses possessed by seeds. In field experiments at La Selva Biological Station, I investigated how collared peccaries (Pecari tajacu) and Central American agoutis (Dasyprocta punctata) affect five species of large seeds that have various defenses against predation. Overall, peccaries consumed and killed most non-defended and chemically-defended seeds but they could not destroy seeds with physical defenses. Agoutis killed non-defended and physically-defended seeds, but not seeds with chemical defenses. Using seeds of Mucuna holtonii, I investigated how chemical and structural defenses deter mammal and insect seed predation respectively. I also determined how endosperm removal by invertebrates affects seed germination and seedling biomass. Chemical defenses protected seeds from rodents, but not ungulates that digest seeds via pregastric fermentation. Physical defenses protected seeds from invertebrate seed predators, and removal of endosperm negatively affected both seed germination and seedling growth. To determine how scatter-hoarding by agoutis affects seed escape from seed predators, germination, and seedling growth, I created simulated agouti hoards. I also investigated how mammals affect young seedling survival. Hoarding enhanced seed survival, germination, and seedling growth for most species of seeds. Terrestrial mammals killed some seedlings via seed predation rather than by herbivory. Overall, large mammal activity in La Selva negatively affected seed and seedling survival and this likely influences many aspects of forest dynamics.
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Tom, Michael William. "The Ecological Effects of Cattle Grazing on Reptiles and Small Mammals in a San Joaquin Valley Grassland." DigitalCommons@CalPoly, 2014. https://digitalcommons.calpoly.edu/theses/1157.
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Livestock grazing is a common and extensive land use practice in the United States occurring in a wide range of habitat types. As such, livestock grazing has the potential to alter ecosystem structure, function and community composition. The primary component (Chapter 1) of this thesis examined the effects of cattle grazing in a San Joaquin Valley grassland on two target taxa: reptiles and small mammals. The study took place on the Chimineas Unit of the Carrizo Ecological Reserve, San Luis Obispo County, California during Fall 2009 and Spring 2010. These taxa were sampled on matched pairs of two grazed and two ungrazed sites. Live trapping methods appropriate to sampling reptiles (coverboards and pit fall traps) and small mammals (Sherman live traps) were used to determine species richness and abundance of these taxa. Uta stansburiana (side-blotched lizard) abundances were greatest on Ungrazed1 (Fall: 1.75±0.49 captures/night, Spring: 3.58±0.35 captures/night). In addition, Chaetodipus californicus (Spiny pocket mouse) abundance was also greatest on Ungrazed1. Population estimates generated by Program CAPTURE suggest C. californicus could be 6.27 times more abundant on Ungrazed1 than Grazed1. However, sample size issues and site level effects confounded and made it difficult to determine significant differences between the grazed and ungrazed treatments for both reptile and small mammal taxa. Habitat structure at these sites was also evaluated including small mammal burrow abundance and vegetation structure. Again, differences between the grazed and ungrazed pasture could not be discerned because of site level effects occurring among matched pairs. As such, this thesis illustrates the difficulty in studying grazing and its potential effects on biotic systems because an array of variables can make unclear the differences between grazed and ungrazed areas. As a follow up study (Chapter 2) I used logistic regression to model U. stansburiana presence to examine possible sources of variation observed at trapping array locations utilized in the main study (Chapter 1). Shrubs exhibited a quasi-complete separation of data points and the three best models included: 1) Bare soil cover (AICc = 28.12), 2) Holes (AICc = 29.76), and 3) Bare soil cover + Holes (AICc = 29.90). Shrubs, bare soil cover and small mammal burrow density were all positively associated with U. stansburiana presence at array locations. Although species have general habitat requirements based upon their ecology and evolution, variations in habitat utilization exists depending upon the resources present at a specific location. Quantifying basic ecological information on a site specific basis is important to managing populations by identifying important resources and habitat components utilized by a given species on a given site.
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Laville, Elisabeth. "Etude morphofonctionnelle et évolutive de l'adaptation au fouissage chez Arvicola terrestris scherman (Mammalia, Rodentia)." Paris 7, 1988. http://www.theses.fr/1988PA077097.
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Une analyse cinéradiographique des modalités du fouissage a montré que le substrat est attaque par des morsures successives puis évacué par les membres. Les mouvements mis en jeu sont stéréotypés et cycliques. Ils correspondent à une adaptation comportementale de l'espèce résultant plus d'un phénomène évolutif que d'une accommodation individuelle ou d'un apprentissage. Une étude biomécanique analyse la poussée exercée par les membres pelviens. Une étude comparative de la morphologie de quelques rongeurs fouisseurs montre que les adaptations au fouissage d'a. Terrestris sherman sont discrètes et touchent l'ensemble du squelette
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Laville, Elisabeth. "Etude morphofonctionnelle et évolutive de l'adaptation au fouissage chez Arvicola terrestris Scherman (Mammalia, Rodentia)." Grenoble 2 : ANRT, 1988. http://catalogue.bnf.fr/ark:/12148/cb376150583.
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Massing, Cody P. "American Pika (Ochotona princeps): Persistence and Activity Patterns in a Changing Climate." DigitalCommons@CalPoly, 2012. https://digitalcommons.calpoly.edu/theses/726.
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An increasing amount of evidence suggests that as temperatures increase, montane animals are moving upward in elevation (IPCC 2007, Parmesan and Yohe 2003). As suitable habitats rise in elevation and then disappear altogether, these animals could be pushed to extinction. The American pika, Ochotona princeps, is a montane mammal that lives in western North America, usually at elevations above 1500 m (Smith and Weston 1990). Recent evidence suggests that pika population numbers are dropping in response to rising temperatures (Beever et al. 2010). The pika is a small herbivorous lagomorph, a relative of hares and rabbits. Its habitat is tightly restricted to talus slopes (rockfields) and the surrounding vegetation (Grayson 2005). Pikas have a high tolerance for cold temperatures, and do not hibernate during the long montane winter. However, they have very little tolerance for even mildly warm temperatures, and have been found to die when confined above ground at 25.5˚ C (Smith 1974b).
To better understand pika persistence, we resurveyed 17 historic pika sites in the Lassen Peak region of northern California in August and September, 2009. Six of the historic sites were abandoned, as well as an additional 11 of 17 new sites surveyed. At each site we collected habitat information, and analyzed the data for factors that were correlated with site occupancy. We also installed 38 iButton thermal dataloggers in abandoned and occupied pika use sites, to determine if temperature affects occupancy. The dataloggers remained in pika sites for 14 months and recorded temperature every 1.5 hours. Abandoned pika sites had higher average temperatures and more days below 0˚ C. They also had greater shrub cover, less forb and graminoid cover, and a greater percentage of litter substrate. These findings suggest that the current warming trend may be having a negative impact on pikas in the Lassen Peak Region. As temperatures rise, pikas may be declining due to unsuitable temperatures and altered vegetative communities.
In addition to the Lassen surveys, I investigated pika behavior in different temperature regimes in the Sierra Nevada. If pikas are able to adapt to climate change, it is possible that populations of pikas in different temperature regimes may exhibit behavioral plasticity, or have evolved genetic differences, such that these populations have different daily activity schedules. To determine if there is a difference in pika behavior at different elevations I observed pikas in one low and one high elevation site within the Bishop Creek drainage system in the Sierra Nevada. I conducted behavioral observations of pikas in four time blocks throughout the day in August and September, 2010. I recorded specific behaviors, such as foraging and haying (vegetation collecting), and compared these activities between low and high elevation pikas at different times of day. In August, pikas in the low elevation site exhibited a different activity profile than those in the high elevation site. Low elevation pikas were significantly more crepuscular (most active at dawn and dusk) during this month. I also observed more foraging behavior in the high elevation than the low elevation site, in both August and September. Reduced activity at higher temperatures may have negative impacts on pikas as temperatures increase. Low elevation pikas may be stressed due to reduced time spent foraging and haypile (overwinter vegetation cache) gathering. However, if pikas were able to switch their activity schedules to a more nocturnal schedule, they could escape higher daytime temperatures. To detect the possibility of nocturnal behavior in low elevation pikas, I set up four infra-red remote cameras in the low elevation site. I had variable success in capturing pika behavior with the cameras, and detected no evidence of nocturnal behavior. More research on the possibility of nocturnal behavior in pikas would be worthwhile, in part to determine what chance, if any, pikas have of adapting to rising global temperatures.
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Berry, Christopher J. J. "Post-dispersal seed predation in a conifer-broadleaf forest remnant : the importance of exotic mammals." Lincoln University, 2006. http://hdl.handle.net/10182/666.
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Despite extensive international acceptance of the critical role of mammalian post-dispersal seed predation in many plant communities, in New Zealand we have limited knowledge of these predators’ influence on plant recruitment in our forests. The principle objective of my thesis was to determine the importance of exotic mammals as post-dispersal seed predators in a New Zealand conifer-broadleaf forest remnant. To address this goal, I used a series of field-based experiments where the actions of different post-dispersal seed predators were separated by wire-mesh exclosures. My study was conducted at Mount Peel Forest Park Scenic Reserve, South Canterbury, New Zealand. Being a human modified conifer forest currently dominated by broadleaf species, it is typical of forest remnants in New Zealand. This presented an opportunity to study a wide range of both potential post-dispersal seed predators and broadleaf tree species. My findings indicate that exotic mammals are not only post-dispersal seed predators at Peel Forest, but are responsible for the majority of post-dispersal predation events observed. Ship rats (Rattus rattus) were the dominant post-dispersal seed predators, while brushtail possums (Trichosurus vulpecula), house mice (Mus musculus) and native invertebrates were also important post-dispersal seed predators for several tree species. Through use of time-lapse video and cafeteria experiments I found that exotic mammalian seed predators, when compared to native invertebrate seed predators, preyed upon larger-seeded plant species and were responsible for considerable seed losses of several tree species. However, exotic mammalian seed predators do share several foraging characteristics with native invertebrate seed predators, as predators foraged in similar habitats and responded in a similar way to changes in seed density. In investigating if post-dispersal seed predation by mammals had a flow-on effect to plant recruitment, I observed natural seedling densities at Peel Forest were significantly higher in the absence of mammalian seed predators, but I found no evidence that the presence of mammals significantly altered the overall species richness. At the community level, I did not find an interaction between habitat and exotic mammals, however I present evidence that for individual plant species a significant mammal : habitat interaction occurred. Consequently, even though my cafeteria experiment implied there was no significant difference in the overall amount of seed preyed upon within different habitats, the less favourable microsite conditions for germination under an intact continuous canopy allows mammals to exacerbate habitat-related patterns of seed mortality and have a noticeable effect on seedling establishment. In an effort to validate the use of manipulative experiments to predict the long-term effect of post-dispersal seed predation on plant dynamics, I attempted to link results of my cafeteria experiment with observed seedling abundance at Peel Forest. Seven tree species were used in this comparison and a strong correlation was observed. This result shows that the level of post-dispersal seed predation determined in the cafeteria experiment provided a good predictor of the effect of mammalian post-dispersal seed predation on seedling establishment. To fully gauge the impact of mammalian post-dispersal seed predators on seedling establishment, the relationship between these seed predators and the type of recruitment limitation experienced by a plant species was also investigated. By using a combination of seed addition, plot manipulations and seed predator exclusion I was able to investigate this relationship. I found evidence that seed limitation at Peel Forest is positively correlated with seed size, and that while mammalian post-dispersal seed predators can further reduce plant recruitment of plant species experiencing seed limitation, the influence of mammals in determining plant recruitment was limited for plant species experiencing microsite limitation. My study has proven that exotic mammals are now the dominant post-dispersal seed predators at Peel Forest, the amount of seed preyed upon varies among plant species, and post-dispersal seed predation by mammalian species can lead to differences in seedling richness and abundance. I proved that the influence of exotic mammals on seedling establishment is also linked to habitat structure and recruitment limitations. When combined these observations suggest that exotic mammalian post-dispersal seed predators may play an important role in determining landscape abundance and distribution of plants at Peel Forest.
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Tomkins, Geoffrey William Osborne. "The relationship between flank organ secretion characteristics and the dynamic features of a natural population of Arvicola terrestris (Mammalia : Rodentia)." Thesis, King's College London (University of London), 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.389620.
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Affonso, Renato de Oliveira. "Tapirus terrestris (Linnaeus, 1758) (Mammalia, Perissodactyla) em uma área de floresta subtropical no sul do Brasil : dieta, uso da área e densidade populacional." Universidade Federal do Rio de Janeiro, 1998. http://hdl.handle.net/11422/3998.
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Previous issue date: 1998<br>CAPES<br>Este estudo apresenta uma análise de dados referentes ao uso do habitat,
dieta, dispersão de sementes, e densidade populacional de Tapirus terrestris no
Parque Florestal Estadual do Turvo, localizado em uma área de floresta
subcaducifólia subtropical, na Bacia do Alto Uruguai, no Estado do Rio Grande
do Sul, Brasil. O estudo foi realizado com base na observação de pegadas;
número e localização de trilhas e bolos fecais, ao longo de dois transectos num
total de 910Km percorridos. Frutos de Syagrus romanzoffiana (Arecaceae) foram
os mais consumidos, sendo substituídos somente quando houve disponibilidade
de frutos estacionais como Holocalix balansae (Caesalpiniaceae) e
Campomanesia xanthocarpa (Myrtaceae). Tapirus terrestris é um bom dispersar
para as espécies de frutos consumidos principalmente para Syagrus
romanzoffiana. Encontrou-se uma proporção bem maior de bolos fecais
depositados no solo do que dentro d'água o que favorece a taxa de germinação
das sementes. A disponibilidade de água, de frutos, a presença de caçadores e a
atividade turística parecem ser as maiores razões para as diferenças observadas
quanto ao uso dos habitats e à densidade da espécie entre as diferentes áreas
do Parque. Áreas sujeitas a uma maior visitação turística apresentaram menores
densidades. As densidades calculadas para o Parque, foram mais baixas do que
as observadas para populações amazônicas submetidas à pressão de caça. A
sazonalidade dos recursos alimentares pode estar parcialmente relacionada com
os valores observados para habitats subtropicais.<br>This study presents an analysis of a data set concerning habitat use, diet,
seed-dispersal role, and density of the lowland tapir (Tapirus terrestris L. )
population from the Parque Florestal Estadual do Turvo in the subtropical forest
of the upper Uruguay river basin, Rio Grande do Sul State, Brazil. The presence
of tapir was determined by following fresh tracks, counting tracks and feaces
found by walking along 910km cumulative transects of trail on roads, and near
creeks. Syagrus romanzoffiana (Arecaceae) was the main fruit in the diet of T.
terrestris, replaced by Holocalix balansae (Caesalpinaceae) and Campomanesia
xanthocarpa (Myrtacea) when available. Viable seeds of this palm were found in
dung piles, suggesting a possible dispersal role of tapirs. The usual deposition of
pile of dungs in non flooded areas may favor the germination of seeds The water
in permanent swamps, the availability of fruits and the presence of hunters seem
to be the main reason for the differences regarding habitat use and density
observed between the studied areas in the Park. The estimated density of Tapirus
terrestris population is below the values observed for hunted areas in Amazonia.
The seasonality of food resources may be partially related to the observed values
for subtropical habitats.
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Oliveira, Gustavo de. "Mamíferos de maior porte em paisagens tropicais alteradas: seu papel em cascatas tróficas e fatores que determinam sua distribuição." Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/41/41134/tde-05042012-114619/.
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Nesta dissertação investigamos o papel dos mamíferos em cascatas tróficas nas florestas tropicais, e os efeitos da configuração espacial e qualidade do habitat assim como das atividades humanas atuais sobre a distribuição de mamíferos de maior porte em uma paisagem rural de Mata Atlântica. No primeiro capítulo, através de uma revisão da literatura sumarizamos e avaliamos a evidência empírica de que mamíferos estão envolvidos em cascatas tróficas em florestas tropicais com o objetivo de indicar os avanços, os problemas e os desafios nessa área. Poucos estudos empíricos e conceituais foram encontrados na literatura, todos realizados nas últimas três décadas, enquanto que a maioria dos estudos empíricos foi realizada nos Neotrópicos. Grande parte das hipóteses relacionadas a cascatas tróficas foi apenas proposta, e considera o homem como predador de topo. Além da maior parte das variáveis quantificadas não serem adequadas para demonstrar efeitos em cascata, a escala temporal da maioria dos estudos revisados foi curta para acessar estes efeitos sobre a comunidade de plantas que contém espécies longevas. Nenhuma hipótese abordou o efeito dos predadores de topo sobre as populações de presas pequenas via o controle da densidade e distribuição de mesopredadores. A maioria das hipóteses que encontramos na literatura se refere a outros efeitos indiretos causados por mamíferos, em particular através da dispersão de sementes e da disponibilização de nutrientes via fezes. Dessa maneira, demonstramos que o termo \"cascata trófica\" tem sido utilizado amplamente, englobando outros efeitos indiretos que se propagam via outras interações que não tróficas, e que a evidência empírica disponível até o momento de que mamíferos desencadeiam cascatas tróficas em florestas tropicais é pequena. No segundo capítulo, através da amostragem de 23 remanescentes florestais e do uso de modelos de ocupação e da abordagem de seleção de modelos, investigamos como fatores associados à configuração espacial e qualidade do habitat e a outras atividades humanas em andamento interagem e condicionam a distribuição de mamíferos terrestres de maior porte em paisagens intensamente modificadas pelo homem. A assembléia de mamíferos de maior porte encontrada na paisagem estudada é simplificada e dominada por mamíferos silvestres generalistas de médio porte, sugerindo que o controle de mesopredadores e a regeneração das florestas podem estar comprometidos. Os resultados também sugerem que: (1) a distribuição de mamíferos de maior porte deve ser condicionada mais por fatores associados à configuração espacial do que à qualidade do habitat florestal; (2) as atividades humanas atuais são tão ou mais importantes que a configuração espacial e a qualidade do habitat para a maioria das espécies. O tamanho dos fragmentos e a distância a rodovias, entre os fatores associados à configuração espacial, e a caça e a presença do cachorro doméstico, entre as atividades humanas atuais, foram particularmente importantes para a distribuição das espécies de mamíferos de maior porte. A relevância das atividades humanas em andamento sugere que estratégias de manejo que foquem em mudanças na atitude da população humana, através de programas de conscientização e educação, podem ter resultados significativos em termos da persistência de populações de mamíferos em paisagens rurais.<br>In this dissertation we investigated the role of large mammals in trophic cascades in tropical forests, and the effects of habitat configuration and quality as well as of current human activities on the distribution of large mammals in a rural Atlantic forest landscape. In the first chapter, through a literature review we summarized and evaluated the empirical evidence that mammals are involved in trophic cascades in tropical forest, with the aim of highlighting the progress, problems and challenges in this area. Few conceptual and empirical studies were found in the literature, all of which were performed in the last three decades, while most of the empirical studies were developed in the Neotropics. Most of the hypotheses related to trophic cascades were only proposed and not tested, and considered humans as top predators. Not only most of the quantified variables were not appropriate to demonstrate cascading effects, but also the temporal scale of most studies was short to detect these effects on plant communities composed of long-lived species. We did not find hypotheses addressing the effect of top predators on the populations of small prey through the control of mesopredator density and distribution. Most hypotheses in the reviewed literature refer to other indirect effects played by mammals, especially through seed dispersal and nutrient allocation via feaces. Thus, we demonstrate that the term \"trophic cascade\" has been used widely, encompassing other indirect effects that propagate through other, non-throphic interactions, and that the empirical evidence available so far that mammals are drivers of trophic cascades in tropical forest is weak. In the second chapter, through the sampling of 23 forest fragments and using occupancy models and a model selection approach, we investigated how factors associated with habitat configuration and quality and with other current human activities interact to define the distribution of terrestrial large mammals in human-modified landscapes. The large mammal assemblage from the studied landscape is impoverished and dominated by medium-sized generalist species, suggesting that both the control of mesopredators and forest regeneration may be compromised. Our results also suggest that: (1) the distribution of large mammals is determined mainly by aspects of habitat configuration rather than by aspects of habitat quality, and (2) current human activities are equally or more important than habitat configuration and quality for most of the species. Fragment size and distance to roads, among the factors associated with habitat configuration, and hunting pressure and domestic dog presence, among those associated with current human activities, were particularly important to the distribution of large mammal species. The relevance of current human activities suggests that management strategies that focus on changing people attitudes, through programs of education, can have significant results in terms of the persistence of mammal populations in rural landscapes.
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Treloar, Shannon. "Potential for resource competition between the boodie (Bettongia lesueur) and mala (Lagorchestes hirsutus) in the fenced Matuwa reserve, central Western Australia." Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 2022. https://ro.ecu.edu.au/theses/2514.
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Translocations to closed systems such as fenced reserves are commonly used for the conservation of threatened fauna species worldwide and although fenced reserves can provide significant conservation benefits to biodiversity, they can also bring forth potential threats. Ecologically similar species can stably coexist by partitioning resources along at least one of three niche dimensions (food, space, or time), thereby reducing interspecific competition. However, resources are limited in fenced reserves and natural processes that regulate populations in response to resource availability, such as dispersal into surrounding areas, are unable to occur. Consequently, there is increased potential for competition because there are less resources available for partitioning. Furthermore, the removal of predators and competitors, both native and introduced, can increase the risk of overpopulation due to a reduction in the incidence of density-dependant mortality. This can potentially lead to overuse of resources and further increase the potential for competition. Interspecific competition may lead to the decline or exclusion of a more sensitive species by a less sensitive species. Such interactions are difficult to predict, especially as many threatened species no longer naturally co-exist in their current ranges or are poorly studied.
I investigated resource use of two potentially competing native marsupials, boodies (Bettongia lesueur) and mala (Lagorchestes hirsutus), that co-exist in a 1100 ha predator-free fenced reserve located in the arid rangelands of central Western Australia. Resource overlap between coexisting populations of these two species has not been studied previously, but the literature suggests the potential for considerable dietary overlap. I investigated the degree of dietary overlap using scat DNA from non-invasively collected scats, as well as the degree of spatial overlap using scat counts and temporal overlap using camera traps. Boom-bust dynamics have been observed in the Matuwa boodie population (and elsewhere), which raised the concern of subsequent suppression of the potentially less competitive mala. The suppression of mala however cannot be confirmed because there are currently no effective methods to monitor the population size of this elusive species at Matuwa. Therefore, I also trialled non-invasive DNA-based sampling methods using field-collected scats to estimate the abundance of the Matuwa mala population. This method has not been used on mala previously.
Results from the dietary analyses suggest there is potential for significant exploitative competition, as both species’ scats consisted of a high percentage of Acacia spp. However, the Acacia DNA could not be identified to species level and there are at least 19 Acacia species within the enclosure, so it is unknown which species they are consuming, and further studies are necessary to resolve the extend of overlap. Additionally, boodies also consumed a much higher proportion of fungi than mala, which may reduce the extent of overall dietary overlap, thereby reducing the potential for resource competition. The species displayed no sign of significant spatial or temporal avoidance at a broad scale, possibly because dietary partitioning exists so there is limited risk from using the same habitats and having similar activity rhythms. The results however, suggest the potential for fine scale spatial and temporal avoidance; this should be investigated further.
This study successfully used non-invasively collected scat DNA to identify individuals and estimate the abundance of the mala population at Matuwa. Spatially explicit capture recapture (SECR) and mark-resight models estimated a population size of over 110 individuals. With refined scat collection methods, DNA-based sampling will be an effective and valuable method for monitoring mala. This is a significant outcome because current methods have limited success with the elusive species, but it is essential the few remaining mala populations are effectively monitored to prevent further decline.
The information gained from this study will contribute to the successful conservation of boodies and mala by adding to existing knowledge and providing insight into the ability of these species to coexist. Finally, this study will contribute to gaining a better understanding of resource use by small mammals and how they partition resources (including food, space and time) in a closed environment where resources are significantly more limited than the wider landscape.
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Espartosa, Karina Dias. "Mamíferos terrestres de maior porte e a invasão de cães domésticos em remanescentes de uma paisagem fragmentada de Mata Atlântica: avaliação da eficiência de métodos de amostragem e da importância de múltiplos fatores sobre a distribuição das espécies." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/41/41134/tde-01052009-125425/.
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Nessa dissertação, avaliei a eficiência e congruência de métodos para amostragem de mamíferos de maior porte e investiguei a influência de fatores múltiplos correlacionados, comuns em paisagens fragmentadas, sobre a distribuição destes animais em remanescentes de Mata Atlântica. Através de amostragens padronizadas em 24 remanescentes florestais de uma paisagem rural com 49% de remanescentes florestais no Planalto Paulista e de um delineamento pareado, no capítulo 2 comparei o desempenho e a congruência de dois métodos (pegadas em parcelas de areia e armadilhas fotográficas) e de dois tipos de isca (banana e iscas de cheiro) para a estimativa da riqueza e taxa de ocorrência de mamíferos de maior porte. Ambos os métodos se mostraram adequados para o estudo destes animais em florestas tropicais e dos fatores que afetam sua distribuição em paisagens alteradas, pois (1) registram as espécies de menor porte e noturnas, (2) podem ser padronizados entre áreas heterogêneas, (3) apresentam desempenho semelhante no registro da maioria das espécies e da riqueza de espécies, e (4) refletem de maneira similar o padrão de ocorrência das espécies entre diferentes áreas. Frente às iscas de cheiro utilizadas, a banana foi a isca mais eficiente na amostragem tanto das espécies herbívoras/frugívoras quanto das espécies onívoras, destacando a necessidade da padronização das iscas utilizadas e do uso de iscas complementares ou de iscas que atraiam uma ampla gama de animais. Usando os dados obtidos com armadilhas fotográficas, avaliei quais fatores condicionam a presença e a freqüência de ocorrência de cães domésticos (capítulo 3) e de mamíferos de maior porte (capítulo 4) nos remanescentes. Esta avaliação foi realizada através da seleção de modelos de regressão construídos com base na relação causal entre os fatores estudados - que pode ser estabelecida a partir de como usualmente se dá a expansão das atividades humanas em florestas neotropicais - e comparados através do critério de informação AIC (The Akaike Information Criterion). Para o cão doméstico, foram considerados quatro fatores: extensão de estradas, quantidade de mata e número de cães domésticos no entorno, e qualidade da vegetação. Foi observada uma forte relação positiva entre o total de residentes e o total de cães domésticos no entorno dos remanescentes. Dentro dos remanescentes, o cão doméstico foi mais registrado do que sete das 11 espécies nativas, sua ocorrência foi mais bem explicada pela quantidade de cães no entorno, e sua freqüência de ocorrência pela diminuição da quantidade de mata no entorno, o que mostra a necessidade de controle populacional desta espécie no entorno de áreas naturais e da manutenção de áreas florestadas mais extensas, menos suscetíveis a entrada deste invasor. Para os mamíferos de maior porte, os fatores considerados foram: quantidade de mata e número de residentes no entorno dos remanescentes, distância à estrada de asfalto, freqüência de ocorrência de cães domésticos nos remanescentes, e qualidade da vegetação dos remanescentes. Os resultados demonstraram que, apesar da ampla variação na resposta das espécies a estes fatores, a distância a estradas de asfalto e a freqüência de ocorrência de cães domésticos, fatores que são correlacionados a disponibilidade de habitat e não são freqüentemente considerados, determinaram a distribuição de um número maior de espécies. A comunidade de mamíferos de maior porte encontrada é simplificada, dominada por espécies generalistas e com poucos dispersores e predadores de sementes e plântulas, o que pode levar a conseqüências negativas para outras espécies e para o funcionamento e regeneração das florestas remanescentes. Estes resultados sugerem que para a conservação de uma comunidade íntegra de mamíferos de maior porte na Mata Atlântica é necessário, não apenas a manutenção de grandes contínuos de mata nativa ou de paisagens com percentual alto de matas remanescentes, mas a redução drástica das perturbações associadas à ocupação e atividades humanas. O manejo e restauração de paisagens devem considerar a proximidade entre os remanescentes florestais e estradas, principalmente as asfaltadas e de alto tráfego, e a importância de campanhas de controle populacional e vacinação de cães domésticos.<br>In this master thesis, I evaluated the efficiency and congruence of methods for sampling large mammals, and investigated the influence of multiple and correlated factors, common in fragmented landscapes, on the distribution of these animals in Atlantic Forest remnants. Through standardized surveys at 24 forest remnants in a rural landscape with 49% of remaining forest in the Planalto Paulista and using a paired design, in chapter 2 I compared the performance and the congruence of two methods (tracks in sand plots and camera-trapping) and of two types of baits (banana and scent lures) for estimating richness and rate of occurrence of large mammals. Both methods are suitable for studying these animals in tropical forests as well as the factors that affect their distribution in disturbed landscapes, because (1) they record medium-sized and nocturnal species, (2) can be standardized among heterogeneous sites, (3) present similar performance for recording most species and richness, (4) reflect in similar ways the pattern of species occurrence among different sites. Compared with scent lures, banana was the most efficient bait for sampling herbivores/frugivores as well as omnivores, highlighting the need to standardize baits and use complementary baits or baits that attract a wide range of animals. Using camera-trapping data, I evaluated which factors determine the presence and the frequency of occurrence of domestic dogs (chapter 3) and of large mammals (chapter 4) in remnants. This evaluation was done through the selection of regression models buit based on the causal relationship among studied factors which can be established from the way expansion of human activities usually happens in neotropical forests and compared through the AIC, The Akaike Information Criterion. For the domestic dog, four factors were considerate: extension of roads, amount of forest and number of domestic dogs in the surroundings, and vegetation quality. It was observed a strong positive relationship between the total number of residents and the total number of domestic dogs in the surroundings. Inside remnants, the domestic dog was more frequently recorded than seven of the 11 native species, its occurrence was better explained by the number of dogs in the surroundings, and its frequency of occurrence by the reduction of the amount of forest in the surroundings, which indicates the need of population control of this invasive species in the surroundings of natural areas and of the maintenance of extensive forests areas that are less susceptible to the entrance of this invasive species. For native large mammals, the considered factors were: amount of forest and number of residents in the surroundings, distance from paved roads, frequency of occurrence of domestic dogs and vegetation quality. Results suggested that, despite the large variation in the responses of species to the studied factors, distance from paved roads and frequency of occurrence of domestic dog, factors that are correlated with habitat availability and are not frequently considered, determined the distribution of a larger number of species. The large mammal community found is simplified, dominated by generalist species and with few seed and seedling dispersers and predators, which can lead to negative consequences to other species and to forest functioning and regeneration. These results suggest that for conserving a complete large mammal community at the Atlantic Forest, not only the maintenance of large tracts of continuous forest or landscapes with high percentage of remaining forest is needed, but also a drastic reduction of disturbances associated with human activities and occupation. Landscape management and restoration should consider the proximity between forest remnants and roads, especially those that are paved and present high traffic, and the importance of campaigns of domestic dog population control and vaccination.
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Pinotti, Bruno Trevizan. "Pequenos mamíferos terrestres e a regeneração da Mata Atlântica: influência da estrutura do habitat e da disponibilidade de alimento na recuperação da fauna." Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/41/41133/tde-21052010-103340/.
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Através da amostragem de 28 sítios em diferentes estádios de regeneração em uma área de Mata Atlântica contínua, procuramos nesta dissertação contribuir para o entendimento dos mecanismos relacionados às mudanças faunísticas observadas durante o processo de regeneração em florestas tropicais, e, assim, melhor compreender o valor das florestas secundárias para a conservação da biodiversidade tropical. Para isso, na primeira parte da dissertação investigamos a influência da regeneração sobre características de estrutura da floresta e disponibilidade de alimento consideradas importantes para diversos grupos da fauna. Encontramos maior profundidade do folhiço, volume de galhadas e disponibilidade de frutos de uma abundante palmeira de sub-bosque nas florestas mais maduras, enquanto que nas áreas em estádio mais inicial de regeneração encontramos maior conexão da vegetação, biomassa de artrópodes no solo e disponibilidade de frutos no total e da espécie de planta mais abundante no sub-bosque. Essas modificações podem estar relacionadas às mudanças na fauna observadas durante a regeneração florestal. As espécies que dependem de características só encontradas nas matas mais maduras, como espaços abertos para movimentação, maior complexidade do chão da floresta, ou determinados recursos alimentares poderiam encontrar limitações em áreas em estádios mais iniciais de regeneração, ao passo que espécies que não dependem desses recursos poderiam se beneficiar da maior disponibilidade total de alimentos, ou da maior conexão da vegetação para movimentação, encontradas nessas áreas. Na segunda parte do trabalho, avaliamos a influência da regeneração e de características estruturais e de disponibilidade de alimento sobre espécies endêmicas (especialistas de floresta) e não-endêmicas (generalistas de habitat) de pequenos mamíferos terrestres. Como previsto, observamos que um grupo de espécies (generalistas de habitat) prolifera nas áreas mais jovens, enquanto que o outro grupo (especialistas de floresta) foi mais comum, embora de maneira mais sutil, nas áreas mais maduras. Esses padrões foram em parte explicados pelas variáveis mensuradas, principalmente a disponibilidade de recursos alimentares. Aparentemente, as espécies generalistas estão se beneficiando da maior disponibilidade de alimentos encontrada nas áreas em estádio mais inicial de regeneração, enquanto que as especialistas possuem maior capacidade de ocupação das áreas mais maduras, onde esses recursos são mais escassos. Portanto, esses resultados sugerem um compromisso (trade-off) entre capacidade competitiva e capacidade de utilização de recursos 101 abundantes, como prevê o mecanismo de nicho sucessional, proposto inicialmente para explicar a sucessão de espécies vegetais. As características encontradas nas florestas mais jovens favoreceram a proliferação de espécies de pequenos mamíferos terrestres generalistas de habitat. Entretanto, o efeito positivo da regeneração florestal sobre as espécies especialistas, de maior interesse para a conservação, foi menos acentuado, de forma que as florestas secundárias abrigaram uma assembléia de pequenos mamíferos terrestres rica, podendo, portanto, representar um importante instrumento de aumento de área e conectividade em paisagens altamente modificadas, como as encontradas na Mata Atlântica. Entretanto, esses resultados não reduzem o valor das florestas maduras, principalmente em paisagens fragmentadas e para grupos mais sensíveis da fauna. Essas florestas devem ser protegidas, assim como deve ser garantida (e se preciso auxiliada) a regeneração das florestas secundárias, para que possam adquirir em longo prazo as condições necessárias à manutenção das espécies e dos grupos de espécies da fauna mais severamente afetados pela secundarização das florestas tropicais.<br>By sampling 28 sites in different regeneration stages in a continuous Atlantic forest area, in this master thesis we aimed to contribute to the understanding of the mechanisms associated with the wildlife changes observed during tropical forest regeneration, and thereby better understand the value of secondary forests for the conservation of tropical biodiversity. In the first part of the thesis we investigated the influence of regeneration on aspects of forest structure and food availability considered to be important to several wildlife groups. We found deeper leaf litter, and higher woody debris volume and fruit availability of an abundant understorey palm in the older-growth areas, while in areas in earlier stages we found higher vegetation connection, higher ground-dwelling arthropod biomass, total fruit availability, and availability of fruits of the most abundant understorey plant species. These modifications may be related to the wildlife changes observed during forest regeneration. Species that rely on features only found in older-growth forests, such as open space for movement, higher complexity of the forest floor, or certain food resources, could find limitations in younger forests, whereas species which do not depend on these resources could benefit from the higher total food availability, or higher 102 vegetation connection for movements, found in these areas. In the second part of the study, we assessed the effect of regeneration and of structural attributes and food availability on endemic (forest specialist) and non-endemic (habitat generalist) terrestrial small mammal species. As expected, we found that a group of species (habitat generalists) proliferate in younger areas, while the other group (forest specialists) is more common, although more subtly, in older-growth areas. These patterns were partly explained by the measured variables, especially food availability. Apparently, the generalist species are benefiting from the increased food availability found in younger forests, while specialist species have greater ability to occupy older-growth areas, where these resources are scarcer. Therefore, our data suggest a trade-off between competitive ability and ability to use abundant resources, as predicted by the successional niche mechanism, initially proposed to explain the succession of plant species. The characteristics observed in younger forests favored the proliferation of habitat generalist terrestrial small mammals. However, the positive effect of forest regeneration on specialist species, of more conservation concern, was less pronounced, so that the secondary forests harbored a rich terrestrial small mammal assemblage, and may therefore be an important tool to increase the area and connectivity in highly modified landscapes, such as those found in the Atlantic forest. However, these results do not diminish the value of old-growth forests, especially in fragmented landscapes and for more sensitive wildlife groups. These forests should be protected, as well as the regeneration of the secondary forests should be guaranteed (and assisted, if necessary), so that these areas could acquire in the long term the necessary conditions to maintain the species and the groups of species most adversely affected by the secondarization of the tropical forests.
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Humbert, Jean-François. "Les metastrongles nematodes parasites pulmonaires du sanglier (sus scrofa l. ) : biologie, epidemiologie et dynamique de la transmission." Orléans, 1988. http://www.theses.fr/1988ORLE2007.
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Le cycle des metastrongles comprend trois phases: - l'adulte vivant dans les poumons de sangliers, le degre d'infestation est fonction de l'age de l'hote; - les oeufs sont disperses par les feces des sangliers, l'expulsion des oeufs subit des variations saisonnieres; - les larves vivant dans les hotes intermediaires, les lombrics
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Tarabon, Simon. "La prise en compte des fonctionnalités écologiques dans l'aménagement des territoires et l'application de la séquence Éviter-Réduire-Compenser : De l'échelle projet à la planification Environmental impact assessment of development projects improved by merging species distribution and habitat connectivity modelling Integrating a landscape connectivity approach into mitigation hierarchy planning by anticipating urban dynamics. Landscape and Urban Planning Améliorer la prise en compte des fonctionnalités écologiques dans la séquence Éviter-Réduire-Compenser Maximizing habitat connectivity in the mitigation hierarchy. A case study on three terrestrial mammals in an urban environment The effects of climate warming and urbanised areas on the future distribution of Cortaderia selloana, pampas grass, in France." Thesis, Avignon, 2020. http://www.theses.fr/2020AVIG0720.
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La biodiversité est confrontée à une érosion accélérée et est devenue une préoccupation environnementale mondiale ces dernières décennies. En France, la séquence Éviter–Réduire–Compenser (ERC) est un des outils réglementaires mis en place dans un contexte de destruction et de fragmentation des habitats d’espèces. Elle permet le développement des territoires tout en visant une absence de perte nette de biodiversité. Cependant, malgré les récentes évolutions réglementaires européennes et françaises, le triptyque ERC présente de nombreuses limites et enjeux d’ordre opérationnel. En positionnant nos travaux à l’interface entre recherche et opérationnalité, nous proposons un cadre méthodologique basé sur plusieurs approches de modélisation afin d’améliorer les processus d’évaluation et décisionnels aux différentes étapes d’aménagement, de la planification à l’opérationnel au moment de l’autorisation des projets. Dans une première partie du travail, nous intégrons les enjeux spatio-temporels de la biodiversité à l’ensemble de la séquence ERC, de l’évaluation des impacts potentiels au dimensionnement des mesures écologiques. À partir du cas précis de l’aménagement du Grand Stade de Lyon, nous montrons l’intérêt de combiner les modèles de distribution d’espèces et les graphes paysager pour identifier les réseaux écologiques et poser un cadre de calcul de l’équivalence écologique basé sur le volet fonctionnel de la biodiversité. Intégrer les dimensions spatiales et temporelles permet d’accroitre la connectivité des habitats et améliorer la conception des projets. Nous montrons ensuite qu’organiser la compensation à l’échelle des territoires en les intégrant aux réseaux écologiques améliore davantage les bénéfices et réduit le risque d’échecs des mesures. Notre démarche est présentée dans le contexte périurbain de l’Ouest de Lyon. Enfin, nous démontrons les implications d’une démarche anticipée et planifiée de la séquence ERC dans la planification stratégique des territoires. Pour cela, nous montrons dans le cadre de la Métropole de Toulouse l’intérêt d’étudier conjointement les dynamiques urbaines et écologiques pour mettre en place une stratégie de conservation de la biodiversité à l’horizon 2040 en assurant l’absence de perte nette sur les habitats d’espèces et leur connectivité selon différentes trajectoires d’urbanisation et de ratio de compensation. Cette thèse offre une approche globale pour orienter les décideurs et améliorer la prise en compte des fonctionnalités écologiques à différentes échelles spatiales et temporelles dans l’aménagement des territoires et l’application de la séquence ERC. Ce travail est basé sur des logiciels novateurs et accessibles pour tous les acteurs et constitue une contribution intéressante à l’appui des maitres d’ouvrage qui souhaitent s’assurer de l’absence d'effets significatifs ou irréversibles sur la biodiversité, et des autorités environnementales qui veillent à ce que l’ensemble des enjeux environnementaux soient bien pris en compte dans la conception des projets d’aménagement<br>Over the past decades, biodiversity erosion has speeded up and become a global environmental concern since. Anthropization has led to. The mitigation hierarchy (avoidance, reduction and offsetting of impacts) is a regulatory tool implemented in a context of habitat destruction and fragmentation, disrupting species’ life cycle. The objective is to achieve “no net loss” of biodiversity following urban development. Although biodiversity conservation regulations have recently better addressed ecosystem functioning, the mitigation hierarchy is still being implemented with little concern for the spatial configuration of ecosystems in the landscape. This thesis hypothesizes that the major difficulties encountered by stakeholders are, in part, methodological and technical. Situating our research at the knowledge-action interface, we propose a methodological framework based on several modeling approaches, to respond to the different scientific and operational challenges. This thesis joins forces with other scientific projects and stakeholders’ networks by exploring complementary axes. To this end, we first integrate spatio-temporal issues of biodiversity into overall mitigation hierarchy application, focusing on potential impacts and dimensioning at “territorial development project” scale through a case study on the new stadium in Lyon (Southern France). Combining species distributions models and spatial graphs improves habitat connectivity and therefore the design of the development projects. Next, we demonstrate the positive impacts on peri-urban habitat connectivity of pooling and anticipating offsets in the suburbs of Lyon. In the last part, we demonstrate the implications of an anticipated and planned approach to the mitigation hierarchy on a planning scale. We consider both ecological connectivity and urban dynamics, in an attempt to minimize the ecological impacts of urban sprawl by avoiding urbanization of areas of highest ecological value and then enhance the application of biodiversity offsetting. This method is tested on projections for the Toulouse conurbation (Southern France) by 2040. Thus, this thesis presents an overall approach that can help to increase habitat connectivity and to improve the design of territorial development projects at different spatial and temporal scales. This methodology is based on freeware available to all practitioners. It will serve planners, designers, and decision-makers needing to ensure that there are no significant or irreversible effects on biodiversity, and environmental authorities making sure that all environmental issues are taken into account in the design of development projects
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Chen, Chiao-Jou, and 陳巧柔. "Estimation and Comparison of the Radiation Hereditary Disease Effect Risk with Terrestrial Mammal in Different Generation Length." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/60943555399902399468.
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Sevigny, J., J. Dulisse, M. Tinholt, Gregg G. (Gregg Gordon) 1961 Stewart, and G. Sinnett. "The application of small-mammal analyses in terrestrial ecological risk assessment, former Yankee Girl Mine, Ymir, B.C." 2007. http://hdl.handle.net/2429/8457.
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A small mammal study was undertaken at the former Yankee Girl Mine, Ymir, B.C. (the “Site”) to determine if metals contaminated tailings and surface soil have resulted in adverse health effects to the terrestrial ecosystem and would require remediation to protect the environment. A screening level Tier I ecological risk assessment conducted by a previous consultant yielded hazard quotients above the regulatory limit for the most sensitive terrestrial receptor at the Site (i.e., field mouse), suggesting the potential for adverse, population-level health effects. The screening level model was calibrated here using new data collected as part of a Site-specific small mammal study (e.g., surface soil and deer mice tissue concentrations). Despite orders of magnitude variations in soil concentrations, deer mice tissue concentrations were similar at all locations (1 control; 3 contaminated), and soil to deer mouse bioaccumulation factors were inversely correlated to soil concentration. The calibrated model yielded hazard quotients well below the regulatory limit, suggesting that deer mice have not been adversely affected. The significance of these findings with respect to remedial and/or management decisions at the Site will be discussed.
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Munyai, Aubrey. "Biodiversity of terrestrial small mammals along an altitudinal transect in the Western Soutpansberg, Limpopo Province, South Africa." Diss., 2015. http://hdl.handle.net/11602/279.
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Keaney, Benedict. "Bogong Moth Aestivation Sites as an Archive for Understanding the Floral, Faunal and Indigenous History of the Northern Australian Alps." Phd thesis, 2016. http://hdl.handle.net/1885/119187.
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The research detailed in this dissertation focuses on plant and
faunal remains preserved in the accumulating sediments at
aestivation sites of the Bogong Moth (Agrotis infusa), in the
crevices of granite tors in the northern Australian Alps.
Analyses have confirmed the preservation of a diverse range of
fossil material, including bird feathers, hairs of small
marsupials occupying the rock crevice niche, fossil pollen and
spores derived from the summit vegetation, and charcoal from
fires in the immediate vicinity of the aestivation sites.
The fieldwork focused on the sampling of deposits at various
aestivation sites representative of different biogeographical
areas to ascertain the sedimentary characteristics of each
region. Three aestivation study areas were located and sampled
for the study, the Brindabella Ranges, the Bogong Peaks and the
Tinderry Range in NSW. The Tinderry Range sites represent the
most easterly geographical region, while the Bogong Peaks site
and Brindabella Ranges sites represent, respectively, the western
and central aestivation site regions of the northern Australian
Alps area. Since preservation of organic material typically
occurs in a stable low oxygen environment, investigation into the
depositional environment is an important aspect of the study to
taphonomically contextualise the environmental proxies.
The palynological preparation of material from the three regions
revealed abundant pollen derived from local vegetation. A rich
assemblage of mammal hair was found in the Bogong Peaks and Mt
Gingera sediments. This record provides a unique faunal proxy of
sub-alpine ecosystems. Levels of charcoal in the sediments
reflect past fire frequency, and are presented in both micro- and
macro-charcoal graphs.
Aestivation site deposits are a unique terrestrial archive
recording ecological change in the montane and sub-alpine
environments for over 1000 years. Despite some chronometric
difficulties, they provide an excellent record of the effects of
local disturbance, such as fires, on the biome and provide
insights into the impact of European settlement, on both
vegetation structure and faunal biodiversity. The study provides
evidence of massive cultural, ecological and climatic upheaval at
sub-alpine elevations in the northern Australian Alps from the
late Holocene up to the present, and illustrates the great value
that aestivation sites hold as terrestrial archives, signalling a
need for further utilisation and investigation in light of rapid
human induced climate change.
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Fisher, Jason Thomas. "Cross-scale habitat selection by terrestrial and marine mammals." Thesis, 2010. http://hdl.handle.net/1828/3649.
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Ecology has been devoted to defining the content of a species’ environment. Defining the extent, or size, of a species’ environment is also pivotal to elucidating species-habitat relationships. More than a home range, this extent integrates an individual’s lifetime experiences with resources, competition, and predators. I theorised that a species’ habitat extent is identifiable from its characteristic spatial scale of habitat selection, which in turn is predicted by body size. I reviewed scale-dependent mammalian habitat selection studies and found that a characteristic scale was typically not identified, but identifiable. Of several ecological predictors tested, only body mass was a significant predictor of the relative size of a species’ characteristic habitat selection scale.
Tests of existing data are confounded by differing approaches, so I empirically tested the scale-body mass hypothesis using a standardised survey of 12 sympatric terrestrial mammal species from the Canadian Rocky Mountains. For each species, support for habitat models varied across 20 scales tested. For six species, I found a characteristic selection scale, which was best predicted by species body mass in a quadratic relationship. Occurrence of large and small species was explained by habitat measured at large scales, whereas medium-
sized species were explained by habitat measured at small scales. The relationship between body size and habitat selection scale is congruent with the textural-discontinuity hypothesis, and implies species’ evolutionary adaptation to landscape heterogeneity as the driver of scale-dependent habitat selection. I applied this principle to examine wolverine habitat selection, and found that anthropogenic fragmentation of the landscape influences that species’ occurrence in space at large spatial scales.
Finally, I contended that the prevailing paradigm equating habitats to resources omits interspecific interactions that are key predictors of a species’ occurrences. I examined habitat selection of martens and fishers in terrestrial environments, and sea otters in marine coastal environments, and tested whether the presence of heterospecifics could explain spatial occurrence beyond landscape structure and resources. In both cases, the presence of heterospecifics explained species occurrence beyond simple resource selection. Interspecific interactions are key drivers of a species’ distribution in space; this is the spatial expression of the concepts of fundamental and realized niches. Body size interacts with landscape structure to determine the scale of a species’ response to its environment, and within this habitat extent, interspecific interactions affect the species’ pattern of occurrence and distribution.<br>Graduate
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Neves, Isabel Maria Queirós das. "Terrestrial mammals of Mozambique : current knowledge and future challenges for conservation." Doctoral thesis, 2019. http://hdl.handle.net/10451/45600.
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Nations must know on what and where to conserve, as required by Convention on Biological Diversity. Only by knowing where we should trust our knowledge of species occurrence, we will be able to make accurate decisions and efficiently allocate the limited resources for improving quality and coverage of species occurrence and distribution and safeguarding biodiversity.
Existing knowledge about the biodiversity of Mozambique is scarce across most taxonomic groups. Long periods of armed conflict seriously affected wildlife and scientific research, contributing to this lack of knowledge. This doctoral thesis aimed to compile and map current knowledge about the occurrence of terrestrial mammal fauna in Mozambique, to discuss the challenges for biodiversity conservation in the country. To meet these objectives, an inventory on terrestrial mammal presence was compiling integrating primary species-occurrence data from 1) the GBIF portal; 2) natural history collections; 3) recent survey reports, and 4) scientific literature.
The first part of this thesis focuses on the update of the list of terrestrial mammal species reported for the country. The second part investigates the data bias and gaps in knowledge regarding the distribution of terrestrial mammals in Mozambique, providing priority areas for future surveys. The third part offers a first assessment on the effectiveness of Mozambique’s conservation areas to protect the lesser-known taxa given global change and further suggests priority areas for conservation. As a final contribution of this research, we discuss the contribution of different data sources to the inventory and the importance of digitization and mobilization of biodiversity data in poorly studied countries.
Overall, the study developed in this thesis is an important starting point and a valuable resource for understanding the occurrence and distribution of terrestrial mammals in Mozambique, contributing with a dataset now acessible for researchers and decision-makers.
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Smit, Anne-Marie. "Life-history patterns of terrestrial mammals in the southern African subregion." Diss., 1995. http://hdl.handle.net/2263/23852.
Full textAbstract:
Life-history features of terrestrial mammals in the southern African subregion were explored in an attempt to identify the factor(s) that may influence the evolution of common mammalian life-history patterns within this subregion. Allometry and phylogeny were found to underly most of the variation observed in life-history features. Residual variation was considered and age at maturity, gestation period and litter size emerged as additional features influencing life-history patterns. Southern African mammals could generally be arranged along a theoretical r-K continuum with small mammals having relatively short developmental periods and relatively large litter sizes represented at one extreme and large mammals having relatively long developmental periods with relatively small litter sizes at the opposite extreme. However, the carnivores did not conform to this expected general gradient suggesting that they may be an exceptional order as far as their life-histories are concerned.<br>Dissertation (MSc)--University of Pretoria, 2011.<br>Zoology and Entomology<br>unrestricted
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DAHAL, PRABHAT RAJ. "Production and validation of Area of Habitat maps for terrestrial birds and mammals." Doctoral thesis, 2022. http://hdl.handle.net/11573/1652626.
Full textAbstract:
An accurate representation of the geographical distribution of species is central to ecological
research and conservation science and practice. Species’ distributions can be represented using a
variety of approaches: geographical ranges, which represent the geographical limits of distributions;
point locality data, which represent species’ known occurrences; or inductive or deductive models,
which usually represent species’ habitat within geographic ranges. Representations of distributions
may contain false presences (commission errors) and/or false absences (omission errors). Recently,
Area of Habitat (AOH) maps, a type of deductive model, have gained traction as a tool to represent
global distribution of species, reducing the often high rate of commission errors in range maps.
AOH models map the distribution of suitable habitat for a species inside its distributional limits.
One of the key challenges in producing AOH maps is to translate knowledge of a species’ habitat (a
complex and species-specific concept) into specific land-cover classes in existing land use/cover
layers. Three different methods (expert-based crosswalk, translation table and global maps of
terrestrial habitat types) have been developed to date to overcome this challenge to produce the
AOH maps. (‘Crosswalk’ is a table translating habitat types in a Habitat Classification Scheme to
land-cover classes in a land-cover layer.) However, the performance of these methods has not yet
been tested. One of the key parts of modeling is validation of the model outputs. This is done by
comparing the model output with real world observations, to quantify omission and commission
errors in the models. The aim of this thesis is to produce and compare AOH models for terrestrial
mammals and birds using different habitat mapping and validation methods. In the second chapter, I
developed a map of global terrestrial habitat types based on the IUCN Red List Habitat
Classification Scheme, and a novel method to estimate the omission and commission error of the
global map of terrestrial habitat types using presence-only data of habitat specialist species
downloaded from open repositories like GBIF (Global Biodiversity Information Facility), eBird
(www.ebird.com), PREDICTS (Projecting Responses of Ecological Diversity In Changing
Terrestrial Systems) and the IBA (Important Bird and Biodiversity Areas) dataset. To date, AOH
maps have been validated using presence-only data for small subsets of species for different
taxonomic groups, but no standard validation method exists for cases where absence data are not
available. In Chapter 3, I developed a novel two-step validation protocol for AOH maps which
includes first a model-based evaluation of model prevalence (i.e, the proportion of a species’ range
that contains suitable habitat), and second a validation using species point localities (point prevalence) using presence-only data. I used 48,336,141 point localities for 4,889 bird species and 107,061 point localities for 420 mammal species. Where point prevalence exceeded model
prevalence, the AOH was taken to be a better reflection of species’ distribution than random. In
Chapter 4, I used the global map of terrestrial habitat types to produce AOH maps for 10,651
terrestrial birds and 4,581 terrestrial mammals. I then applied the validation protocol developed in
Chapter 3 to AOH maps of terrestrial birds and mammals produced using translation table and
global maps of terrestrial habitat types. I found that the average model prevalence for AOH maps
produced using the global map of terrestrial habitat type was lower (0.55±0.28 for birds and
0.51±0.29 for mammals) than those produced using the translation table (0.64±27 for birds and
0.65±0.28 for mammals). This led to higher omission errors in the AOH maps produced using the
global map of terrestrial habitat types. Also, the number of AOH maps which were better than
random was higher in the AOH mapset produced using the translation table. I also found a high
similarity between these two sets of maps (53.44% mapped as suitable and 23.22% mapped as
unsuitable in both datasets for birds and 58% mapped as suitable and 19% mapped as unsuitable in
both datasets for mammals). Each AOH map produced using the global map of terrestrial habitat
types was effectively a subset of the equivalent AOH map produced using the translation table,
because the former was based on a single map for each habitat type, whereas the latter was based on
one-to-many relationships between habitat types and land-cover classes. I conclude that, overall,
AOH maps based on the translation table are more robust than AOH maps based on the global map
of terrestrial habitat types in terms of reducing commission errors of the geographic range maps
without introducing large omission errors. However, for species occurring primarily in human-
modified habitats, the AOH maps based on the global map of terrestrial habitat types are more
robust as few human-modified habitats are not mapped by the translation table but are mapped in
the global map of terrestrial habitat types. The AOH modeling and validation methods developed in
this thesis can help update the AOH maps in the future with latest data on land-cover, habitat and
elevation. Furthermore, the validation metrics can be used as a guideline by the users to select the
most appropriate AOH map for their use.
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Yusefi, Gholamhosein. "Conservation Biogeography of Terrestrial Mammals in Iran: Diversity, Distribution, and Vulnerability to Extinction." Doctoral thesis, 2019. https://hdl.handle.net/10216/122186.
Full text
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Yusefi, Gholamhosein. "Conservation Biogeography of Terrestrial Mammals in Iran: Diversity, Distribution, and Vulnerability to Extinction." Tese, 2019. https://hdl.handle.net/10216/122186.
Full text
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KOMENDOVÁ, Barbora. "Biodiverzita drobných zemních savců na loukách s odlišným typem managementu a vodního režimu na Třeboňsku." Master's thesis, 2012. http://www.nusl.cz/ntk/nusl-136993.
Full textAbstract:
The thesis builds on previous work comparing biodiversity of small terrestrial mammals at four localities with different management. The thesis significantly extends the previous work. The theoretical part consists of a literature search on the issue of the occurrence of small mammals in an area around the town Třeboň, their microhabitat preferences and the impact of farming on biodiversity of their communities. The practical part describes the species composition of small terrestrial mammals? communities and changes of their abundance and biomass during the three growing seasons, depending on the climatic characteristics of the locality. It includes evaluation of the results of the regular catches in traps (CMR method), which were realized from June to September between 2009 and 2011 (three catches once a year) at four sites with different management: Mokré louky - non mowed, Mokré louky - mowed, Cirkvičný meadow and a pasture (meadow) Jeţek. A total there were 553 individuals of small terrestrial mammals caught and we noted nine species: Microtus arvalis, Microtus. agrestis, Micromys minutus, Apodemus sylvaticus, Sorex araneus, Sorex minutus, Neomys anomalus, Neomys fodiens, Crocidura suaveolens and Apodemus sylvaticus. Various characters of biotopes provide differently suitable conditions for the establishment of populations according to their habitat requirements. The predominant species in Mokré louky mowed and non-mowed was Microtus agrestis and in the Cirkvičný meadow and Jeţek it was Microtus arvalis. The highest abundance and diversity were recorded in Mokré louky mowed and non-mowed. The highest biomass was recorded in 2009 and 2010 in summer, when temperatures were highest. In 2011, there was the highest biomass in the spring, probably because the previous winter was very warm. The highest Simpson's index of species diversity was in Mokré louky mowed in 2010. The relative abundance was highest of Microtus agrestis, Apodemus sylvaticus and Sorex araneus, alternately in Mokré louky mowed and non-mowed. Microtus arvalis had the highest abundance for all three years in the Cirkvičný meadow. The probability of capture during capture was always increasing, reaching 100%, as in the Microtus arvalis, Microtus agrestis, as well Apodemus sylvaticus. The highest probability of re-capture was at Apodemus sylvaticus, where 33% of the second day and 43% of the third day. The results presented in the thesis contributed to the project NPV 2B06023 MŠMT.
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Wang, Szu-Yi, and 王思懿. "Spatial Distribution Prediction, Protected Area Coverage and Hotspot Analysis of Terrestrial Protected Mammals in Taiwan." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/20738720280885478070.
Full textAbstract:
碩士<br>國立臺灣大學<br>生態學與演化生物學研究所<br>102<br>Spatial distributions of flora and fauna are critical information for research and conservation. When studying distribution of rare, enigmatic, sparsely recorded or broadly distributed species, researchers can model their potential habitats with species distribution modeling techniques. Species distribution modeling can depict the potential habitat distribution of species by analyzing their occurrence records and environmental variables of study area. To date, these techniques have been applied to various biological and geographic research.
Most protected mammals in Taiwan are of high-level consumers in the food chain, threatened by human activity and habitat destruction. However, research on distribution of protected mammals in Taiwan has so far been incomplete. There is also a lack of further application of the distribution information.
In this study, I collected observations of 11 protected mammal species between 1988 and 2013, and modeled the potential distribution of each species with three distribution modeling techniques namely maximum entropy, genetic algorithm for rule-set production and ecological niche factor analysis. The resulted habitat suitability map of each species was obtained by ensembling the outputs of three species distribution models. In order to conquer the data defects caused by uneven sampling, two thresholds were selected, translating the habitat suitability maps into boldly predicted and conservatively predicted presence–absence maps respectively. For further analysis, I calculated protected area coverage of each species and compared the distribution of protected mammal hotspots with protected areas, evaluating the effectiveness of protected areas in Taiwan.
The results showed that the protected area coverage varies between species, with Cervus unicolor swinhoei, Martes flavigula chrysospila and Naemorhedus swinhoei higher than 50%; and Prionailurus bengalensis chinensis and Paguma larvata taivana lower than 20%. Considering the average protected area coverage of all 11 protected mammals, is 38.9% when boldly predicted; and 43.7% when conservatively predicted. Moreover, 41.7% of boldly predicted protected mammal hotspots are covered by protected areas; 53.7% of conservatively predicted protected mammal hotspots are covered by protected areas. The elevation of protected mammal hotspots is slightly lower than protected areas.
I recommend enhancing the protection of low to medium altitude species, such as designating habitat of low to medium altitude species as protected areas or restricting lowland forest exploitation.
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Yen, Shih-Chih, and 顏士致. "Activity Patterns and Habitat Uses of Larger Terrestrial Mammals in Cat Tien National Park, Vietnam." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/59249514830677212175.
Full textAbstract:
碩士<br>國立屏東科技大學<br>野生動物保育研究所<br>97<br>Daily activity pattern and habitat selection are important ecological data for understanding wildlife conservation. The resource competition and niche division by sympatric animals, is vital for sustainable resource allocation in ecological management.
Cat Tien National Park (CTNP), the largest lowland rainforest in South Vietnam, contains diverse habitats, sustaining a high biodiversity of fauna. Human activities however surrounding the boundary and illegal activities inside the national park are causing a serious problem, threatening this unique biodiversity.
Camera trapping was used from July, 2006 to July, 2007 in CTNP to systematically survey the medium-to-large terrestrial mammal populations. Together with habitat factor measurement, daily activity pattern and habitat selection were analyzed. Seventy camera traps with 209 rolls of film were used, resulting in 4696 photographs from 3523 working days. Species confirmed present included 26 mammals, 15 birds, and one lizard from camera traps, with additional confirmation of four more mammal species from direct sightings.
Daily activity patterns were confirmed in three species, including nocturnal common palm civet (Paradoxurus hermaphrodites), diurnal species of pig-tailed macaque (Macaca leonina) and lesser mouse deer (Tragulus javanicus). Another five species with insufficient photographs were analyzed for reference.
Fourteen independent variables are used in analysis of habitat selection of eight species with more than 30 useful photographs. Based on the data collected from different species, Multiple Linear Regression, Negative Binomial Regression, and Zero-Inflated Negative Binomial Regression are used. Forest type and the distance to the nearest guard station are found to be the most influential factors in habitat selection.
For the eight species, distribution and relative abundance are discussed from the locations of the camera traps and their frequency of occurrence. For the species with insufficient data from camera trapping, other animal tracks and direct sightings are used with former study results to get better understanding of their distribution.
According to this research, human activity has become influential in animal activity patterns and habitat uses. Illegal human activities should be controlled based on the power of forest guard station. To make the database more comprehensive, arboreal mammal research is required. Long term monitoring toward non-specific mammals is necessary in understanding their population status and sustainable management.
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Ke, Ling-Hua, and 柯伶樺. "Effects of land use on the community structure and habitat selection of terrestrial small mammals in Wuling." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/04468818725562105267.
Full textAbstract:
碩士<br>國立中興大學<br>生命科學系所<br>99<br>Variabilities of environmental conditions in habitats may affect the animals in different ways, such as population characteristics and community structure. I investigated terrestrial small mammals in habitats of three different types of land-use (grass, orchard, forest) in the Wuling area, in order to understand how differences in environmental conditions affect small mammal population characteristics and community. A total of six rodents and shrew species were captured during the study period. Except for the Chinese white-toothed shrew (Crocidura rapax kurodai) which had very low capture rate, the effects of environmental conditions on population characteristrics differed in the five other species. .Population density, age composition, overwinter frequency and home range size of the Taiwan wood mouse (Apodemus semotus) were affected by habitat types and other environmental factors; sex ratio also differed in two forest blocks. In Père David’s red-backed vole (Eothenomys melanogaster), population density and overwinter frequency were affected by habitat types; population density differed in two forest blocks, and overwinter frequency were different between sexes. Sex ratio and age were not affected by environmental conditions, but the home range size differed between age and forest blocks. Population density, overwinter frequency and home range size of the harvest mouse (Micromys minutus) differed among habitat types; its population density, sex ratio, and age composition varied between blocks, and the main effects of home range size variation were different in difference blocks. The population density of Taiwanese mole shrew (Anourosorex yamashinai) varied among habitats and between seasons. In the Taiwanese brown-toothed shrew (Episoriculus fumidus), population density and age structures were affected mainly by season and habitat types; the size of home range differed between seasons and sexes. It is concluded that not all population characteristics can be attributed to differences in habitat quality, and there are species-specific response in population characteristics to habitats. Small mammal communities were mainly clustered into three groups based on habitat types, and 93.3 % of the variance of small mammal community can be explained by the percentage of ground wreckage branches cover, grass cover, grass height, shrub and tree cover, and number of trees. Except in a orchard block, individuals could move among all other sampling patches, making these patches connected in different degrees. As different species responded differently to environmental changes, it is necessary to analyze environmental conditions in multiple scales in order to understand population and community behaviors of small mammals in fragmentation landscapes.
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Nemakhavhani, Tshifhiwa. "Spatial and reproductive differentiation of small terrestrial mammals in a complex environment in the Western Soutpansberg Mountain, Limpopo Province." Diss., 2015. http://hdl.handle.net/11602/283.
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Tejada-Lara, Julia Victoria. "Testing Foundational Tenets of Stable Isotope Ecology Analyses in Neotropical Mammalian Communities, and Implications for Terrestrial Paleoecology." Thesis, 2020. https://doi.org/10.7916/d8-8d1s-jt27.
Full textAbstract:
Stable isotope analyses are powerful tools for reconstructing ancient ecologies and ecosystems, as they are independent of morphology and directly reflect dietary ecology. The application of stable isotope analyses, however, is not without limitations, as determination of food web dynamics using these methods often relies on poorly tested assumptions. The guiding thread of this thesis is the testing of foundational cornerstones on which these methods rely, in order to validate the suitability of applying these techniques to different mammalian clades, and to more reliably and confidently interpret the isotopic signals preserved in extinct organisms.
The first chapter of this thesis tests the validity of an important assumption behind the interpretation of stable carbon isotope analyses for understanding diet in terrestrial mammalian herbivores: if, as assumed for almost two decades, mammalian bioapatite δ¹³C is enriched by 14‰ relative to dietary δ¹³C. By analyzing new isotopic data from a never before assessed herbivorous group spanning a broad range of body masses—sloths (Xenarthra, Mammalia)— and other mammals with experimentally controlled or observationally known diets, I discovered considerable variation in diet–bioapatite δ¹³C enrichment among mammals. Statistical tests (ordinary least squares, quantile, robust regressions, Akaike information criterion model tests) documented independence from phylogeny, and a previously unrecognized strong and significant correlation of δ¹³C enrichment with body mass for all mammalian herbivores. A single-factor body mass model outperformed all other single-factor or more complex combinatorial models evaluated, including for physiological variables (metabolic rate and body temperature proxies), and indicated that body mass alone predicts δ¹³C enrichment. These analyses, spanning more than 5 orders of magnitude of body sizes, yield a size-dependent prediction of isotopic enrichment across Mammalia and for distinct digestive physiologies, permitting reconstruction of foregut versus hindgut fermentation physiologies for fossils and refined mean annual paleoprecipitation estimates based on δ¹³C of mammalian bioapatite.
Second, I sought to evaluate the existing paradigm governing identification of closed canopy rainforests in the fossil record using mammalian δ¹³C data: the presence of mammals with dietary δ¹³C <-31‰, which has only been observed in closed canopy rainforests in Equatorial Africa, the only other tropical ecosystem sampled extensively. This chapter provides a characterization of δ¹³Cbioapatite, δ¹³Chair and δ¹⁵Nhair of a modern mammalian community in western Amazonia, in Peru, to test if the isotopic structure of mammals in this Neotropical ecosystem is similar to those in African tropical rainforests. The results indicate that despite their marked geographical and taxonomic differences, median δ¹³Cdiet values from closed canopy rainforests in Amazonia (-27.4‰) and equatorial Africa (-26.9‰) are not significantly different. Amazonian mammals, however, seem to exploit a narrower spectrum of dietary resources than equatorial African mammals, as depicted by the absence of highly negative δ¹³Cdiet values previously proposed as indicative of rainforests (<-31‰). I hypothesize that differential effects of late Pleistocene extinction may be responsible for the ecological disparities among the two rainforests, by significantly reducing evolutionary time and dietary breadth reflected in the modern Amazonian mammalian community.
Finally, the third chapter of this dissertation evaluates assumptions behind δ¹⁵N amino acid compound specific analyses in order to test the controversial hypothesis of carnivory and consumption of proteins of animal origin in fossil sloths. This analytical technique relies on three main assumptions. First, that the offset between the δ¹⁵N of glutamic acid (δ¹⁵NGlx) and phenylalanine (d15NPhe) in the organism under study will increase with increasing trophic level. Second, that the offset between δ¹⁵NGlx and δ¹⁵NPhe at the base of the food chain is relatively constant and has a value of -8.4‰ for C3 ecosystems. Third, that the trophic discrimination factor in all ecosystems (the difference in δ¹⁵NGlx relative to δ¹⁵NPhe with increasing trophic level) is 7.6‰. The results of my experiments conducted on extant xenarthrans (sloths and anteaters) with controlled diets document that only the first assumption holds true. Rather than relying on an equation with constants introducing uncertainties and that are not applicable to organisms feeding on a combination of items of different origin (e.g., C3 + C4 plants), δ¹⁵NGlx and δ¹⁵NPhe values by themselves can accurately reconstruct the trophic position of organisms. Indeed, the results on δ¹⁵NGlx and δ¹⁵NPhe herein obtained for five xenarthran species in controlled feeding experiments, combined with mammalian data available from the literature, show strong and significant correlations between these two AAs and with trophic positions. Both the TP equation and the regression analyses of δ¹⁵NGlx and δ¹⁵NPhe suggest that the Pleistocene fossil ground sloths 𝘔𝘺𝘭𝘰𝘥𝘰𝘯 𝘥𝘢𝘳𝘸𝘪𝘯𝘪𝘪 and 𝘕𝘰𝘵𝘩𝘳𝘰𝘵𝘩𝘦𝘳𝘪𝘰𝘱𝘴 𝘴𝘩𝘢𝘴𝘵𝘦𝘯𝘴𝘪𝘴 were not pure herbivores as commonly presumed, but rather that they were both mixed feeders/omnivores, incorporating items of animal origin in their diets.
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KOUTNÍKOVÁ, Lenka. "Vliv způsobu hospodaření na biodiverzitu modelových skupin obratlovců {--} drobní savci." Master's thesis, 2010. http://www.nusl.cz/ntk/nusl-50720.
Full textAbstract:
This thesis creates a part of more extensive scientific study, which evaluates effects of different agricultural management on ecological functions and on landscapes´s water regime in source water areas of Bohemian Forest. A one of examined characteristic of catchment is biodiversity of plant and animal communities. The aim of my thesis is a comparsion of diversity of small terrestrial mammals in three catchments with similar nature conditions, but different management. Small terrestrial mammals is a group of vertebrates often used for study of enviromental state, because of their high reprodctive potential, good invasive ability and ability to indicate the changes in environmental quality. The master thesis is a follow-up to a previous bachelor thesis and extends it significantly. A teoretical part involves literary review of small mammals´s occurrence in Bohemian Forest, their micro-habitat preferences and the effect of management on the biodiversity of their communities. Practical part of the thesis contains evaluation of the results of capture-mark-release trapping, which took place from June to September of the years 2007 and 2009. In those two years 52 individuals were captured. From this amount, 7 individuals were captured twice. Captured small mammals were included into 5 species, whose occurrence in studied localities was expected. There were yellow-necked mouse (Apodemus flavicollis - 22 individuals), field vole (Microtus agrestis - 6 individuals), common vole (Mircotus arvalis - 10 individuals), bank vole (Clethrionomys glareolus {--} 2 individuals) and common shrew (Sorex araneus - 5 individuals). In the Bukový potok catchment 20 individuals were captured in 2007 and only 2 individuals in 2009. They belong to species: Apodemus flavicollis, Clethrionomys glareolus and Sorex araneus. In catchment of Mlýnský potok no individual was captured in 2007 and 10 individuals of only one species (Mircotus arvalis) were captured in 2009. In Horský potok catchment 5 individuals were captured in 2007 and 8 individuals in 2009. Three species were found: Apodemus flavicollis, Microtus agrestis, Clethrionomys glareolus a Sorex araneus. The largest positive change of abundance between 2007 and 2009 was found in the Mlýnský potok catchment. The largest fall of abundanace was in the catchment of Bukový potok. Only in catchment of Horský potok the relatively stable abundance was noticed. The thesis was supported by projects: MSM 6007665806, NAZV-QH82106 a NPV2-2B08006.