Dissertations / Theses on the topic 'Desert animals'

Many zoo facilities record weight data for their animals as part of their management protocols. However, there is a lack of evidentiary support in the literature on captive animal management for the use of this data as a health management tool and little discussion on the many ways in which keepers can interpret weight data. Often, animals' weights are considered in the context of their health only when other signs suggest health compromise. While aberrant weight values as secondary signs of illness are useful in confirming health compromise, it is possible that changes in weight can be observed as initial clues to illness. This study explores this possibility but acknowledges the need for an understanding of baseline weight values in order for comparisons to be possible. Furthermore, the study seeks to characterize the baseline weight data for a variety of captive Sonoran Desert animals, so that an individual weight value may be evaluated in the context of the norm for a particular animal species over a span of time. Specifically, animal care staff members at the Arizona-Sonora Desert Museum expect that weight data may express patterns of seasonality, due to the changes that animals undergo with time of year.

Endothermic homeothermy is a major feature of the adaptive suites of tachymetabolic animals such as mammals and birds. The advantages homeothermy confers on birds and mammals include relative independence from the environment, a stable internal milieu, and possibly the ability to sustain high aerobic activity (Bennett and Ruben 1979). Some mammals in situations of limited water or energy availability, however, depart markedly from homeothermy and instead display patterns of heterothermy. Torpor is a lowering of body temperature (T(b)) to conserve energy and/or water. I studied the energetics of arousal from torpor in two desert pocket mice species. The species differed in warming rates and arousal durations, but used similar amounts of energy to arouse. The smaller species, Perognathus amplus, lost mass more quickly while fasting in the cold, yet waited as long as the larger species, Chaetodipus baileyi, before entering torpor. P. amplus maintained a lower T(b) during topor than C. baileyi. The thermodynamics of arousal indicated that metabolic rate during arousal was a function of T(b) but not ambient temperature (Tₐ), that the animals changed thermal conductance to increase heat gain when Tₐ was greater than T(b), and that Q₁₀ decreased during arousals. In contrast to torpor, adaptive hyperthermia provides desert mammals in dry, hot environments a means to conserve water that would normally be used for evaporative cooling. I modeled the effects of body size on adaptive hyperthermia and discovered that small mammals gain the most in terms of water savings using this strategy, and that small and large mammals can spend larger fractions of the day active than do medium size mammals. I demonstrated that two desert ground squirrel species make use of adaptive hyperthermia during the summer near Tucson, Arizona by following free-ranging squirrels implanted with temperature-sensitive radio transmitters. Ground squirrel T(b) fluctuated almost continuously, ranging from about 35°C to over 42°C, and rarely approached steady state. Of the two species studied, Ammospermophilus harrisii had higher mean T(b), similar maximum T(b), and lower T(b) variability compared to Spermophilus tereticaudus. These results are consistent with the more wide-ranging foraging style of A. harrisii compared to S. tereticaudus.

Animals were given a preponderant position in Egyptian art, symbolism, and cultual practices. This thesis centres on the relationship between humans and animals during the predynastic period in Upper Egypt (Naqada I-IIIB, 4th millennium BCE), focusing on hippopotamus and crocodile as representatives of the Nile environment and antelope species as representatives of the desert environment. Depictions of these animals are analysed and compared with contemporary faunal remains derived from activities such as cult, funerary, or every day consumption. The material analysed covers several centuries: temporal evolutions and changes have been identified. The animals studied in this thesis were first used by the Naqada I-IIB elites as means to visually and practically express their power, which they envisioned in two contrasting and complementary ways. The responsibilities of the leaders were symbolised by the annihilation of negative wild forces primarily embodied by antelope species. In contrast, they symbolically appropriated positive wild forces, chief among them being the hippopotamus, from which they symbolically derived their power. Faunal remains from after mid-Naqada II are few, depictions of hippopotamus disappeared and those of crocodile became rare. Antelope species became preponderant, especially on D-ware vessels, which were accessible to non-elite people. However, toward the end of the predynastic period, antelope species came to be depicted almost exclusively on high elite material; they lost their individuality and became generic representatives of chaotic forces that the leaders and early rulers had to annihilate in order to maintain control and order.

I studied diel activity patterns of female desert bighorn sheep ( Ovis canadensis mexicana) in the Little Harquahala Mountains, Arizona, July 1985-June 1986. Diurnal activity patterns were similar throughout the year. Nocturnal activity patterns were similar for all seasons except spring when activity significantly (P = 0.003) decreased. Bighorn sheep were active an average of 39 and 33% of any given hour during the day and night, respectively. Diurnal ambient temperatures and relative humidity were significantly (P ≤ 0.048) correlated with bighorn sheep activity during all seasons. Bighorn sheep spent a majority of the time foraging in the fall and winter, but spent more time resting during spring and summer. Bighorn sheep obtain water in their food throughout the day; percent moisture content of forage species remained high (≥ 32%) for any given hour of the day throughout the year.

The number of desert bighorn sheep (Ovis canadensis mexicana) in Pusch Ridge Wilderness (PRW), Santa Catalina Mountains, Arizona has declined to between 50 and 100 animals. Sheep have restricted movements to the southwest corner of PRW. I developed a model based on nitrogen (N) content of forage and forage quantity to measure seasonal changes in nutritional carrying capacity of sheep use areas in PRW. Forage based estimates of animals numbers were greater for April to September than for October to March. My study suggests that forage is not limiting desert bighorn sheep in PRW and illustrates the potential to support more desert bighorn sheep in PRW than the current population. Seasonal fluctuations in range productivity should be examined in relation to human disturbances proximal to desert bighorn sheep habitat and fire management programs for PRW.

Variability is a universal, but poorly understood, property of ecosystems. A common belief that environmental variability has a destabilizing effect on species coexistence is being challenged by a growing body of theoretical research; variance in resource abundances may actually promote species coexistence. Here, I develop three models which give ecological conditions for coexistence on a single resource. The first considers a resource whose abundance varies seasonally. Coexistence may be possible if there is a tradeoff between foraging efficiency and maintenance efficiency. The first species can forage profitably on low resource abundances while the second uses dormancy to "travel" inexpensively between temporal periods of high resource abundance. The second considers a resource whose abundance varies spatially. Coexistence may be possible if there is a tradeoff between foraging efficiency and the cost of travel. The first species forages patches to a lower giving up density while the second can inexpensively travel between patches with high resource abundances. The third considers an environment in which foraging costs change seasonally. Coexistence may be possible if there is a tradeoff between the cost of foraging during different seasons. The species which is the most efficient forager changes seasonally. Because coexisting species often exhibit little apparent diet or habitat separation, seed-eating desert rodents offer a promising community for testing the three aforementioned mechanisms of coexistence. In a community of four granivorous rodents, (Perognathus amplus, Dipodomys merriami, Spermophilus tereticaudus, and Ammospermophilus harrisii), I used artificial seed patches to measure species and habitat specific foraging efficiencies. The third mechanism of coexistence appears to explain the presence of P. amplus, D. merriami, and S. tereticaudus in the community. Each enjoys a season during which it is the most efficient forager. The second mechanism of coexistence explains the presence of A. harrisii in the community. This species preferred to forage a large number of widely spaced patches to a high giving up density rather than foraging a few patches to a low giving up density.

Predation by exotic predators (cats Felis catus and foxes Vulpes vulpes) is believed to be one of the factors that has contributed to the decline of medium-sized mammals in arid Australia. Other factors include habitat degradation by introduced herbivores (rabbits Oryctolagus cuniculus and grazing stock) and altered fire regimes after Aboriginal people moved into permanent settlements. In general, the impact of exotic predators on arid zone mammals is believed to be significant only when predator numbers have been elevated by increased food availability from exotic prey species (rabbits, house-mice Mus domesticus, cattle carcasses) or when native prey populations have already been dramatically reduced by competition from introduced herbivores. In much of the spinifex grasslands of the central Australian deserts, pastoralism never occurred, rabbit colonisation was extremely patchy and in some areas, traditional burning was still being practised when the extinctions commenced. None of the current models of mammalian extinctions adequately explain the declines in this environment. In this study I examined predator-prey interactions in two areas of the Tanami Desert to investigate whether predation by exotic predators may be a primary agent of extinction in its own right, capable of causing mass declines even in the absence of other human-induced perturbations. If this were the case then the following would be expected: (i) cats and foxes would eat medium-sized mammals when they are available, but be able to survive on alternative prey when mammals are scarce; (ii) populations of cats and foxes would be buffered against the declines of mammals during droughts, or would be able to recover more quickly than medium-sized mammals after droughts; (iii) medium-sized mammals would be more vulnerable to predation by cats and foxes than by dingoes Canis lupus dingo and other native predators, and (iv) there would be a correlation between the timings of the extinctions and the colonisation (or sudden increase) of cats and foxes. These predictions were investigated by monitoring the diets and relative abundance of cats, foxes and dingoes in relation to fluctuating prey availability in two areas of the Tanami Desert at latitudes separated by approximately 400 km. Mean annual rainfall is higher and more reliable in the northern study area which was situated in the centre of bilby Macrotis lagotis distribution within the Northern Territory, whereas the southern study area was located on the southern edge of the bilby�s range. Within each study area, monitoring occurred at three sites, approximately 20 km apart. Each site contained a sub-plot in each of two habitat types. Field work was conducted between September 1995 and December 1997. When the study began, the southern study area was experiencing drought conditions, however both study areas received significant rainfall in early 1997. The population dynamics of a variety of potential prey groups were monitored to examine their resilience during droughts, patterns of recolonisation after rainfall, and use of two habitat types: the ubiquitous sandplain, and the moister, nutrient enriched palaeodrainage habitat which is believed to have provided a refuge for medium-sized mammals during droughts. Native mammals were uncommon throughout the study period. Bilbies and macropods were significantly more abundant in the northern study area, and tended to occur more frequently in palaeodrainage habitat than sandplain. However, the palaeodrainage habitat did not appear to provide adequate refuge for the medium and large mammals during drought conditions in the southern study area, as they disappeared from the study sites altogether. Small mammals were significantly more abundant in the southern study area but densities remained low (less than 2% trap success) throughout the study, and showed little response to improved seasonal conditions. In contrast, the abundance and species richness of birds showed a marked increase following rainfall in the southern study area. Flocks of nomadic birds arrived within several months of drought-breaking rains, increasing the relative abundance of birds from 9.3 per km of transect in December 1996 to 49/km in July 1997. Reptiles were the most resilient prey group during the drought conditions. Both varanids and smaller reptiles were equally abundant in the wet and dry years and showed no difference in abundance between study areas. However, reptiles showed marked temperature-related patterns in activity, with many species becoming inactive in the winter months. A total of 142 cat scats, 126 fox scats and 75 dingo scats were analysed to investigate predator diets in the two study areas. Unlike cat, fox and dingo diets elsewhere in Australia (and the world), mammalian prey did not dominate. Reptile was the prey category that was most frequently consumed by cats and foxes in �summer� (October-April) and by dingoes throughout the year, and was identified as a �seasonal staple� prey type for all three predators in the Tanami Desert. When biomass of prey was taken into account, the varanids (predominantly the sand goanna Varanus gouldii) were the most important prey sustaining predators in the two study areas. Birds were an important part of the diets of cats and foxes in winter when reptiles were less active. Small mammals were consumed by cats and foxes throughout the study, in proportion to their field abundances. Invertebrates were a major component of the diets of foxes, representing 31% of prey items consumed. There was considerable overlap in the diets of the three predator species, but dingoes ate more medium (100-999 g) and large (greater than 1000 g) prey than cats and foxes did. The scarcity of medium-sized mammals in the study areas provided little opportunity to find evidence of predation events on such prey. However, bilby remains were found in two cat scats and one dingo scat in the northern study area, mulgara Dasycercus cristicauda remains occurred in several cat and fox scats from the southern study area, and there were fourteen occurrences of marsupial mole Notoryctes typhlops in predator scats during the study, primarily in fox scats. Elsewhere in Australia, there is ample evidence that cats and foxes regularly consume medium-sized mammalian prey (e.g. rabbits and ringtail possums Pseudocheirus peregrinus) when it is available. Overall cats were the most abundant eutherian predators in the two study areas, and they were significantly more abundant in the northern study area than the southern study area. Surveys revealed that cats can persist into droughts by feeding on reptilian prey. When the study commenced, cats occurred on five of the six sub-plots in the southern study area, despite six consecutive years of below-average rainfall. However, by the end of the first year, they could only be detected on one sub-plot. Recolonisation of the sites rapidly occurred after significant rainfall (260 mm in 2 months), when nomadic birds colonised the sites and provided a plentiful food source. Foxes also declined to very low densities during drought in the southern study area, but they had recolonised all sites by the winter of 1997. This coincided with the increase in abundance of birds, which became their most frequently consumed prey item. Overall, foxes were equally abundant in the two study areas, but statistical analyses revealed a significant interaction between latitude and habitat because in the southern study area foxes tended to utilise the palaeodrainage habitat more than the sandplain, whereas in the northern study area the majority of fox sign was detected in the sandplain habitat. This may have been due to the abundance of dingoes in the palaeodrainage habitat in the northern study area. Dingoes were significantly more abundant in the northern study area than the southern, where they were usually only present at one of the three sites. The northern study area had higher densities of macropods (supplementary prey for dingoes) and more reliable access to drinking water, which persisted in the palaeodrainage channels for up to 6 months after significant rain events. Dingo numbers were relatively stable throughout the study and did not increase in response to improved seasonal conditions in the southern study area in 1997. This study revealed that the distribution of foxes extends further north into the Tanami Desert than has previously been reported, and is not necessarily tied to the distribution of rabbits in the Northern Territory. Furthermore, discussion with Aboriginal people who lived a traditional lifestyle in the area until the 1940s, revealed that foxes were already present in the northern Tanami desert at that time, before the disappearance of many medium-sized mammal species. The patterns of medium-sized mammalian extinctions in the northern and western deserts between 1940 and 1960 is thus consistent with the colonisation of the fox. Although cats had been present in central Australia for at least 50 years before the mammalian declines occurred, this does not discount them from contributing to the extinction process. It is postulated that during the early decades of their colonisation of the arid interior, cat populations may have been maintained at low levels by predation from dingoes and also Aboriginal people (for whom cats were a favoured food). But between 1920 and 1960 the western deserts were depopulated of Aboriginal people, and human hunting of cats diminished. This coincided with the introduction of the dingo bounty scheme, which encouraged many Aboriginal people to continue making regular excursions into the deserts to collect dingo scalps. In this study, cat remains occurred in 9% of dingo scats, suggesting that dingoes may be an important predator of cats. Thus, there may have been an increase in the cat population between 1930 and 1960, producing a more significant impact on native mammal populations than had previously occurred. Information collected during this study was used to construct a new model of mammalian extinctions in the spinifex grasslands of central Australia that promotes predation by cats and foxes as the primary agent of extinction. The model proposes that cats and foxes will eat medium-sized mammals when they are available, but are capable of subsisting on naturally occurring alternative prey when mammals are scarce. Thus, cats and foxes can persist into drought periods by feeding on reptilian prey, which remains an abundant resource regardless of rainfall (at least during the warmer months). Predator populations eventually decline after a series of dry winters. When the drought breaks, the rapid response of nomadic birds provides a readily available food source for cats and foxes as they recolonise areas and commence breeding. Predation by cats and foxes thereby has the potential to exacerbate the declines of native prey populations during droughts and delay their recovery when seasonal conditions improve. In this way, introduced predators are capable of causing local extinctions of medium-sized mammals when populations contract during drought periods, even in the absence of introduced herbivores and altered fire regimes. Although dingoes also prey upon medium-sized mammals, dingoes did not cause extinctions of medium-sized mammals in the spinifex grasslands because (i) they are more reliant on drinking water than foxes and cats, thus waterless areas would have provided some degree of predation refugia, and (ii) their social structure and territoriality prevent high densities accumulating, even when resources are abundant. If further extinctions of medium-sized mammals (such as the bilby) are to be prevented, it may be necessary for wildlife managers to establish a series of predation refugia where fox and cat populations can be controlled without extinguishing local dingo populations. This could be achieved with a combination of predator-proof enclosures, zones in which foxes are killed through poison baiting and areas where Aboriginal people are employed to utilise traditional hunting methods to control introduced predators.

Human encroachment into wilderness areas can influence the persistence of wildlife populations by decreasing and degrading habitat, displacement, and decreasing survival. For bighorn sheep (Ovis canadensis), some human activities are detrimental, causing both physiological stress and habitat abandonment. Between 1979 and 2000, human recreation has increased over 300% in areas occupied by desert bighorn sheep (O. c. nelsonii) in southeastern Utah. We investigated if an increase in human activity in areas used by bighorns affected their behavior. We observed 34 bighorn sheep using focal-animal sampling for >14 hrs to compare time spent grazing and scanning between areas of high and low human use. We identified group size, presence or absence of a lamb, distance to escape terrain, and human use (high versus low) as potential explanatory variables that influenced grazing and scanning times, and created an a priori list of models based on these variables. We used Akaike's Information Criterion adjusted for small sample sizes (AICc) to rank models, and used model selection to find a best approximating model (lowest AICc value) for both behaviors. Desert bighorn sheep spent less time grazing and more time scanning in high human use areas (22% grazing, 29% scanning) than in low human use areas (54% grazing, 8% scanning). Caution should be taken when considering which areas or trails should be opened during these important seasons to minimize and reduce additional stresses to bighorns caused by human activity. Bighorn sheep populations experienced significant declines after European settlement in North America. Today, the primary practice of bighorn sheep conservation is through population restoration and augmentation from remnant source populations. We conducted a 9-year telemetry study for a source population of desert bighorn sheep in Canyonlands National Park, Utah. We captured and collared 58 bighorn sheep from 2002-2009. To estimate annual and seasonal survival, we used known-fate analysis in Program MARK 4.1. We used model selection to test hypotheses for bighorn survival, including sex, age, human use, year, and month, as possible explanatory variables. There were 20 mortalities during the study. Annual survival ranged from 83% - 88% with no significant variation among any of the years. Model selection results showed that the top six models included a temporal variable (e.g. season or month), and carried 92% of the AICc weight. Population persistence for bighorn sheep can be compromised by high levels of predation, habitat fragmentation, and disease transmitted from domestic sheep. We suggest that land managers continue to maintain the separation of domestic sheep from bighorns in CNP. We also recommend that survival studies continue to ensure that future translocation projects do not occur at the expense of the source population.

Traditional stylistic classifications have not provided conclusive dates for the rock art of the Sahara, and the imagery can therefore not be placed securely in its cultural or environmental context. This thesis proposes a new methodology in which content and patina of the engravings are used to establish a chronological sequence, against the background of changing palaeoenvironmental conditions. This framework can then be used to explore aspects of the relationship between the rock art and the changing Holocene landscape. The engravings of the Wadi al‐Hayat, which were recently recorded by the Fezzan Rock Art Project, form the basis of this research. A total of 2466 images of animals were individually analysed and entered into a database. The depicted species are shown to reflect the local fauna, and their habitats coincide with the palaeoclimatic conditions of the central Sahara. Additionally, recent geomorphological analyses of the rock surfaces of the Messak provide a chronology for the patina, and show that the formation of each type of patina was dependent on environmental conditions. Through analyses of the animal engravings, categorised according to positively identifiable species and patina types, this thesis demonstrates a direct correlation between the content (i.e. species depicted) and patina of the engravings, and the palaeoenvironment. Both content and patina of the engravings indicate a development from wet savanna to dry savanna, and finally to desert conditions, consistent with the Holocene climatic sequence. This provides a chronological framework for the engravings and places them into a palaeoenvironmental context. The locations of the engravings of each patina group also correspond to the changing lake levels of the al‐Hayat palaeolake identified in previous palaeoenvironmental research projects, which in turn supports the chronology of the engravings. Through spatial analyses, the locations and landscapes preferred by the engravers for the creation of rock art can be identified, whilst the new chronological sequence allows us to explore changes in the cultural conventions that underlie the creation of the engravings. As well as providing a chronological framework and environmental context for the engravings for the Wadi al‐Hayat, the research presented in this thesis therefore has the potential to change our understanding of Saharan rock art.

Climate change and exotic plant invasions are significant anthropogenic threats to desert community structure and resilience . In the Mojave Desert, the invasive grass red brome (Bromusrubens L) is increasing fire frequency and extent in response to climatic factors. The resilience of this ecosystem will be affected by how plant and animal communities respond to fire. To better understand these dynamics, we studied the environmental factors underlying changes in invasive grass fire regimes in the Mojave Desert and its structural and functional effects on plant and animal communities. Following fire, reestablishment of native vegetation can be preempted by repeated burning associated with the abundant exotic grass red brome. Red brome density is correlated with various climate and landscape variables, but to establish causality, we experimentally assessed germination and growth of red brome. Red brome responded positively to fall precipitation, finer-textured soils, fertile-islands soils, and soils from burned landscapes. Red brome germination is maximized in wet fall periods when adequate water and optimal temperatures overlap . To evaluate landscape responses of pre- and post-fire plant communities and the potential for repeated burning we analyzed vegetation greenness (NDVI) data from 1985-2011 in response to temperature and precipitation. Landscape analysis indicated that the dominance of exotic grasses increases on post-fire landscapes. Following wet fall and winter seasons, high red brome productivity increases fire potential. Without mitigation, the establishment of an invasive-plant-driven fire regime is likely and may drive state transitions from arid shrublands to arid annual grasslands. Potential revegetation of post-fire landscapes will depend at least in part upon the physiological response of surviving vegetation to post-fire landscapes. Plant physiological responses to post-fire landscapes were generally neutral or positive, suggesting that revegetation of post-fire landscapes is not precluded by resource loss associated with fire and may even be enhanced by post-fire conditions. This will likely translate to increased reproductive potential of surviving plants. Alterations to small mammal populations will likely play a role in the reestablishment of vegetation (both native and exotics) as small mammals have strong top-down effects in arid ecosystems. Diversity and species richness responded negatively to burned landscapes as Merriam's kangaroo rat (Dipodomys merriami) increased in abundance while other species practically disappeared from burned landscapes. Merriam's kangaroo rat affects propagule sources through direct consumption, and seed dispersal. Increases in abundance and dominance of Merriam's kangaroo rat will likely alter plant recruitment.

The landscapes of the Great Basin and Mojave Deserts are changing due to plant invasion. Highly flammable invasive grasses increase the size and frequency of fire causing a cascade of effects through the plant and animal communities. One of the most influential animal groups in desert systems is small mammals. We sought to learn how small mammals are impacted by fire and how their influence on the plant community differs between burned and unburned habitat. Small mammals did not have higher rates of mortality as a direct result of a controlled burn. In the Great Basin, there were short-term reductions in abundance, richness, and diversity of the small mammal community in burned plots. In the Mojave, species richness and diversity increased in burned plots shortly after fire and no abundance differences were detected. These results correspond with our prediction based on the dominant small mammal species at each site. Small mammals are primarily granivores; however, they also have strong impacts on the plant community via folivory. We tested for small mammal impacts on seedling survival in burned and unburned habitat. Small mammal access, burned vs. unburned habitat, and plant species were all important determinants of survival. Small mammals greatly reduced survival at both sites in burned and unburned habitat and often had a stronger impact in unburned than burned plots. Accounting for small mammal folivory may be a crucial step in successful post-fire rehabilitation. Finally, we used seed trays to test how small mammals influence the persistence of seed on the landscape. Small mammals reduced persistence of an invasive and native plant species in the Great Basin in 2012, yet a year later when small mammal abundance was reduced, no small mammal effect was observed. In the Mojave, persistence was reduced for the majority of species both years of the study. Small mammals did not appear to avoid seed of invasive plant species as we had predicted and may be important consumers reducing the reproductive potential of these invaders. If small mammals do prefer non-native seedlings over natives and are also consuming non-native seed, they may be greatly reducing the presence of non-natives both on the unburned landscape as well as after fire. Non-native consumption by small mammals could aid in the biotic resistance of these desert ecosystems. This research further enforces the important role that small mammals play as consumers, dispersers, and regulators of the plant community.

Biocrusts and the ecosystem services they provide are becoming more susceptible to fire as exotic annual grass invasions facilitate the spread of desert wildfires. Further, precipitation patterns across the western United States are predicted to change over the next century, and have the potential to dramatically influence fire regimes and the recovery of burned biocrusts. Despite these changes to desert fire and precipitation cycles, our understanding of post-fire biocrust recovery is limited, especially regarding the first two years after fire. To investigate biocrust recovery, we created burn manipulations (i.e., unburned and burned) and tracked crust form and function over two years in one cold and one hot desert ecosystem (UT, USA). We evaluated the entire bacterial community, but focused on Cyanobacteria species that confer soil stability and N fixation capabilities to biocrusts. Specifically, we quantified shifts in biocrust bacterial community composition using target metagenomics of 16S rDNA; monitored biocrust moss and lichen cover; measured N fixation potential; and assessed soil infiltration rates and soil stability. We found little evidence that biocrust form or function recovered from fire within two years. Based on pyrosequencing results, fire altered biocrust community composition in interspace and shrub biocrusts. Cyanobacteria species were almost completely eliminated by fire, constituting 9-21% of unburned plots and less than 0.01% of burned interspace and shrub biocrust communities. Based on cover estimates, no lichen or moss species survived the fire or recovered within two years. N fixation potentials decreased by at least six-fold in burned interspace biocrusts, representing a reduction in soil N inputs into already N-limited desert soils. Soil infiltration rates also drastically declined in burned biocrusts and remained depressed, but only remained depressed for one year. To investigate the interactions between biocrust recovery, fire, and precipitation, we nested precipitation treatments manipulating the amount of monthly rainfall (i.e., ambient, plus 30% and minus 30%) within burn treatments during the second year. Soil NH4+ was the only parameter to be affected by precipitation, and exhibited a positive relationship with precipitation magnitude at the end of one year. Our results demonstrate that fire is a strong destabilizer of the bacterial components of biocrust communities and that the ecosystem services provided by crusts recover at different rates, with N dynamics recovering more slowly than soil ecohydrology.

Following its introduction to North America in the late nineteenth century, Bromus tectorum L., an inbreeding invasive winter annual grass, has become dominant on millions of hectares of sagebrush steppe habitat throughout Intermountain Western North America. It appears that within the last 30-40 years, B. tectorum has expanded its range southward into the Mojave Desert and also into more climatically extreme salt desert environments. Previous research using microsatellite markers and experimental studies has suggested that lineages found in desert habitats are genetically distinct from those found in the sagebrush-steppe habitat and possess suites of traits that pre-adapt them to these environments. To provide additional support for our hypothesis that desert habitat-specific haplotypes dominate and are widely distributed across warm and salt desert habitats, we genotyped approximately 20 individuals from each of 39 B. tectorum populations from these habitats and adjacent sagebrush steppe habitats using 71 single nucleotide polymorphic (SNP) markers. Our data clearly demonstrate that populations throughout the Mojave Desert region, as well as in salt desert habitats further north, are dominated by a small number of closely related SNP haplotypes that belong to the desert clade. In contrast, populations from adjacent environments are largely dominated by haplotypes of the common clade, which is widely distributed throughout the North American sagebrush steppe. Populations across all habitats were usually dominated by 1-2 SNP haplotypes. This suggests that inbreeding B. tectorum lineages can often maintain their genetic integrity. It also explains the strong association between marker fingerprints and suites of adaptive traits in this species.

Made available in DSpace on 2015-04-14T13:35:44Z (GMT). No. of bitstreams: 1 449056.pdf: 2018454 bytes, checksum: e1cb8245a85f0c29d0e1f07814420e60 (MD5) Previous issue date: 2013-03-15
Chronic cartilage lesions, like septal and auricular perforations, are easily found at the otolaryngologist office. Its treatment is a challenge for physicians and patients, due to few alternatives and limit success. With the objective to decrease the surgical procedures, it s been studying alternative methods for the total regeneration of the cartilaginous defects. The use of cellular therapy had been used in some cases, but there are no chronic cartilaginous protocols well written in the medical literature to compare the different results. This paper has the objective to describe a chronic cartilaginous lesion in an experimental model, for future studies with cellular therapy.
Les?es cartilaginosas cr?nicas, como as perfura??es septais e auriculares, s?o facilmente encontradas no consult?rio do otorrinolaringologista. Seu tratamento ? um desafio tanto para o m?dico quanto para o paciente, devido a poucas alternativas e sucesso limitado. Com o objetivo de diminuir a morbidade dos procedimentos cir?rgicos, cada vez mais t?m sido estudados m?todos alternativos para a regenera??o completa dos defeitos cartilaginosos. O uso de terapia celular j? est? sendo utilizado em alguns casos, por?m n?o h? protocolos de les?es cartilaginosas cr?nicas bem descritos na literatura m?dica a fim de se obter compara??es adequadas desses resultados. Este trabalho tem por objetivo descrever uma les?o cartilaginosa cr?nica em um modelo experimental, para estudos futuros com terapia celular.

The following thesis offers a philosophical critique of sociobiology, which is identified as a recent attempt to produce a general theory of animal behaviour, encompassing an account of human nature. The first chapter examines the empirical and theoretical foundations of sociobiology, highlighting some of the philosophical topics regarding the relation of the natural and social sciences, and the attempt to offer an account of human nature within a largely mathematical and mechanistic theoretical framework. Chapter two looks at the major specific areas of human behaviour featured in sociobiological accounts. A close examination of empirical evidence, underlying theoretical assumptions, behavioural categories and definitions, and finally deduced conclusions reveals several weaknesses and examples of fallacious reasoning. The third chapter continues to examine the account of human nature in relation to the broadest and most abstract features of social structures and interactions. The political dimension of sociobiology is examined - both in terms of its account of political behaviour, and in the theoretical opposition between sociobiology and left wing ideologies. The sociobiological account of religious behaviour is rejected in favour of one couched in terms of social rather than genetically heritable dispositions. Chapter four evaluates the attempt to respond to early criticisms of sociobiology. It is argued that the main theoretical stance regarding human behaviour remains little changed, and that the new theoretical models create even more conceptual problems, thus failing to provide a framework for an account of human nature. The final chapter applies some ideas from evolutionary theory to specific areas of philosophical controversy: the relation of mind to language; the ascription of mental life to other species; functionalist and epiphenomenaiist accounts of consciousness. It is argued that empirical and theoretical considerations from the natural sciences may thus inform traditional areas of philosophical debate, creating useful interdisciplinary dialogues.

Currently the size and frequency of wildfires are increasing at a global scale, including arid ecosystems that exhibit great sensitivity to disturbance. Fire effects on plant pollination and reproductive success in deserts are largely unknown. Plant dependence on animal pollinators for reproduction can increase the risk of reproductive failure if pollination services are hindered or lost. Species that depend on few taxonomically related pollinator species are expected to be most negatively affected by disturbances that disrupt pollination interactions. To assess fire and isolation effects on reproductive success in desert plant communities, and how wildfire influences the pollination success of generalist and specialist pollinated plants, the number of flowers, fruits, and viable seeds produced by plants surviving in burned and unburned desert landscapes were compared. Fire increased flower production for wind and generalist pollinated plants, and did not affect specialist plant flower production. Increases may be associated with positive physiological responses exhibited by plants surviving in burned areas. Fire did not affect pollination services. Wildfire effects on fruit production were neutral or positive, and overall seed:ovule ratios varied by 3% or less in burned and unburned areas for each pollination strategy. Increasing isolation within burned areas did not affect fruit production for generalist or specialist pollinated plants, suggesting that pollination services are functional across expansive burned desert landscapes. Annual reproductive output varied between years in burned and unburned areas, and shifts likely resulted from variation in annual precipitation patterns. Reductions in landscape reproductive output may be partially compensated by increased per plant fruit and seed production and maintaining pollinator services across burned landscapes, providing native shrub communities the possibility to naturally recover from fire disturbances. Habitat disturbances can influence plant interactions with herbivores, in addition to pollinators. To understand how fire and ungulate herbivory affect reproductive success of specialist pollinated desert plants, reproductive effort, floral herbivory, and pollinator visitation and success, were compared for Yucca baccata, and Yucca brevifolia in burned and unburned areas of the Mojave Desert. Fire increased Y. baccata flowering from 12% to 22% of plants in burned areas, but had no effect on the number of flowers or fruits produced per plant. Fruit set and pollinator collection failed at all sampled Y. baccata individuals, while fire and herbivory had no effect on Y. brevifolia flower, fruit, and pollinator collection. Herbivores consumed 50% and 67% of floral stalks produced by Y. baccata in unburned and burned areas. Herbivores pose a clear threat to successful sexual reproduction for Y. baccata. Removal of ungulate herbivores during important flowering periods may still result in failed fruit and seed production if local pollinator reserves have been drastically reduced or lost.

Historically, kit foxes (Vulpes macrotis) once occupied the desert and semi-arid regions of southwestern North America, ranging from Idaho to central Mexico. Their range-wide decline has warranted the kit fox to be listed as endangered in Colorado, threatened in California and Oregon, and designated as a state sensitive species in Idaho and Utah. Once considered the most abundant carnivore in western Utah, the kit fox has been in steep decline over the past decade, creating a demand to determine kit fox presence. Currently there is little consensus on which survey methodology is best to detect kit fox presence. We tested 4 survey methods (scat deposition, scent station, spotlight, trapping) along 15 5-km transects within a minimum known population of radio collar kit fox. Home range sizes for kit foxes on the study site were extremely large, averaging 20.5 km2. Scat deposition surveys had both the highest detection probabilities (= 0.88) and were the most closely related to known fox abundance (r2 =0.50, P = 0.001). For detecting kit foxes in a low density population we suggest using scat deposition transects during the breeding season. This method had low costs, was resilient to weather, had low labor requirements, and entailed no risk to the study animals.Next in determining kit fox presence is estimating kit fox distribution. We developed resource selection functions (RSF) using presence data from the noninvasive scat surveys to model kit fox distribution. We evaluated the predictive performance of RSFs built using three popular techniques (Maxent, fixed-effects and mixed-effects general linear models) combined with common environmental parameters (slope, aspect, elevation, soil type). Both the Maxent and fixed-effects models performed to an acceptable level with relatively high area under the curve (AUC) scores of 0.83 and 0.75, respectively. The mixed-effects model over valued higher elevations and had poor model fit. This study demonstrated that it was possible to create valid and informative predictive maps of a species distribution using a noninvasive survey method for detecting a carnivore existing at low density. By demonstrating the application of noninvasive surveying to model habitat quality for a small mesocarnivore, wildlife management agencies will be able to develop predictive maps for species of interest and provide more knowledge to help guide future management decisions.

Ion exchange resin capsules provide a possible alternative to conventional soil testing procedures. Previous studies with semi-arid, low fertility soils observed poor relationships with poorly mobile nutrients such as phosphorus (P). We propose that placement depth may improve those relationships. Our objective was to (1) determine if placement depth could improve resin capsule estimation of the bioavailability of nitrogen (N), P, and sulfur (S) and (2) to determine if resin capsules can effectively estimate S availability in semi-arid, low fertility soils. Field sites were established in Rush and Skull Valleys, Utah on loam and sandy loam soils, respectively. Fertilizer was surface applied as ammonium sulfate and triple superphosphate with six N, P and S treatments (0, 5.5, 11, 22, 44 and 88 kg ha-1 of N and P2O5 and 0, 7, 14, 28, 56 and 112 kg ha-1 of S). Thirty 4.0-m2 plots were established at each field location. Resin capsules were placed three per plot at 0–5, 5–10, and 10–15 cm deep in the soil and soil samples taken at respective depths. The capsules were removed and replaced after approximately 90 d. Final removal and soil sampling occurred approximately 240 d later. For the second study, fertilizer was surface applied as ammonium sulfate with six S treatments (0, 7, 14, 28, 56 and 112 kg ha-1 of S) with one resin capsule placed in each 4.0-m2 plot at a depth of 5 cm in the soil. Resin capsules were removed and replaced approximately every 90 d for a total of four samplings. Soil samples were taken with every resin capsules install and removal. In the first study, bicarbonate extractable P was significantly related to P application at all depths and times except the two lowest depths at the time of final sampling, and resin capsule P was only related to P application 398 days after application in the 0–5 and 5–10 cm depths. However, this is an improvement in estimates of bioavailability compared to a single placement depth. The 5–10 cm depth was the best for placement for determination of NH4-N, and resin capsules improved upon soil test estimates. For NO3-N, depth was not important, but resin capsules had a stronger relationship with N applied than the soil test 398 d after application. In addition, both resin capsules and the S soil test were related to S applied, but resin capsules were more able to pick up S cycling through the system. In the second study resin capsules and conventional soil tests were both effective in distinguishing between fertilizer rates, though only the conventional soil test was related to S applied at the last sampling (366 d after fertilizer application). Overall resin capsules were effective at reflecting application rates, and may be a good tool to estimate nutrient bioavailability. Correlation with plant uptake is required to determine if soil tests or resin capsules were a better estimate of bioavailable nutrients.

Commonly used soil analysis and resin capsule procedures are used to assess nutrient status in fertile soils, but their validity in semi-arid ecosystems is unknown. Three studies were performed to assess resin capsule effectiveness in semi-arid ecosystems. An incubation study was completed in which loamy sand and sandy clay loam soils were treated with rates of N, P, Fe and Zn. Each soil treatment was implanted with a resin capsule and incubated for 60 or 120 days. Resin capsules reflected NH4-N and P fertilizer at low rates in the loamy sand. NO3-N reflected rates in both soils, but did not reflect Fe or Zn application. Resin capsule NH4-N was a better indicator than KCl-extractable NH4-N, but resin capsule NO3-N was not as effective as water extraction, and resin capsule P was poor compared to NaHCO3-P. A second study was performed in glasshouse conditions using the incubation study soils. Soils were treated with rates of N, P and resin capsules were placed in pots. Pots were seeded with squirreltail grass (Elymus elymoides) and placed in a glasshouse. Resin capsules were removed at 120 days, soil samples taken, grass harvested and yield measured. Yield and total nutrient removal was correlated to resin NH4-N, marginally related to resin or soil NO3-N, and unrelated to resin P. Yield and total nutrient removal was correlated with application rates and resin NH4-N and NaHCO3-extracted P. The third field study, compared two sites with rates of N and P application were established on clay loam and sandy loam soils. Resin capsule and conventional soil tests for NO3-N, NH4-N and P were measured and plant nutrient status examined. Resin capsules were removed and replaced and soil samples taken every 90 days. Resins P was not related to P application or to plant tissue P but NaHCO3-extracted P was, while resin NO3-N, KCl-extracted NO3-N and NH4-N were correlated to N application and plant N. Soil test P was more effective in predicting P status and bioavailability than resin capsules. Resin NH4-N and NO3-N predicted N status and bioavailability, but soil tests were just as effective in semi-arid conditions.

This thesis explores the nexus between landscape design processes and the conservation of wildlife diversity. Extinction of earth’s unique and diverse animal species is progressing at unprecedented rates, due to humanity’s profound alteration of the natural landscape. Scientific literature increasingly points towards opportunities in the urban and landscape design fields to this issue. Unfortunately, the science and needs of wildlife are rarely integrated in rigorous ways in the planning and design of human landscapes. This gap in professional practice protocols and regulatory frameworks in much of the western world is explored and raises questions about how design can successfully protect, restore, and even re-create viable habitat and linkages for wildlife that is integrated with human landscape. Australia has modeled new integrated wildlife-centric design approaches and projects there demonstrate accumulated expertise in the specific area of wildlife habitat design. Through a case study of Australia’s Alice Springs Desert Park, I argue that balancing human and wildlife needs at every step of the design and building process is necessary for successful wildlife habitat design. This integrated approach does not view wildlife and humans as independent, but rather as two interdependent habitat participants that must coexist to ensure the future of both.

El deterioro del medio ambiente, debido a la actividad humana, causa cambios en las comunidades de seres vivos que los habitan. Esto tiene un impacto directo sobre el comportamiento de alimentación de las aves granívoras. Este estudio se propone evaluar los hábitos de alimentación, específicamente, las preferencias y sus causas, de semillas de gramíneas por tres especies de ave: Poospiza ornata, Saltatricula multicolor y Diuca diuca del Desierto del Monte de Mendoza (Argentina). Según la Teoría de Forrajeo Óptimo (TFO), un animal prefiere ítems alimenticios que maximizan su consumo de energía por unidad de tiempo de manipulación. La hipótesis de trabajo es que las aves prefieren semillas que les permiten optimizar el tiempo de manipulación, la eficiencia de manipulación y la rentabilidad de la dieta. Se realizaron experimentos de elección y no elección de semillas y se evaluaron las correlaciones entre las preferencias y el tiempo de manipulación (s), la eficiencia de manipulación (g/s) y la rentabilidad (kJ/s) de semillas. Según el protocolo aplicado, el tiempo de manipulación de las distintas semillas fue diferente dentro de cada especie de ave; sin embargo, el tiempo de manipulación no incidió en las preferencias de las tres aves observadas. Los resultados obtenidos muestran que las especies de mayor tamaño de pico prefirieron las semillas más rentables y que manipularon más eficientemente, que a su vez, fueron las más grandes dentro del rango de semillas ofrecido. En cambio, la especie más pequeña prefirió semillas de todos los tamaños; por consiguiente, no hubo un efecto de la rentabilidad ni de la eficiencia sobre el comportamiento de forrajeo de esta última. Es plausible que si P. ornata prefiriera semillas que manipula con mayor facilidad, éstas serían demasiado pequeñas para satisfacer sus requerimientos energéticos, mientras que si prefiriera las semillas más rentables demorarían demasiado tiempo en manipularlas. En consecuencia, esta especie podría estar prefiriendo semillas que en conjunto compensen ambas variables y maximicen la eficiencia de la dieta, otorgándole una cierta flexibilidad en su comportamiento. En contraposición, la dieta de las especies de mayor tamaño, S. multicolor y D. diuca, podría verse afectada en sitios perturbados donde hay una disminución de las semillas de mayor tamaño, es decir, las preferidas por estas aves.
The environmental degradation, due to human activity, modifies the communities of species that inhabit it. Therefore, this might has a straight effect on the feeding behavior of granivorous birds. This study aims to evaluate the feeding habits, specifically, the preferences, and their causes, of grass seeds by three bird species: Poospiza ornata, Saltatricula multicolor and Diuca diuca from the desert of Mendoza (Argentina). According to Optimal Foraging Theory (OFT), an animal must prefer items that maximize its energy per unit of handling time. Our hypothesis is that birds prefer seeds that allow them to optimize handling time, handling efficiency and the profitability of the diet. The experimental evaluation of seeds preferences was carried out by a combination of choice and non-choice trials, that were correlated with handling times (s), handling efficiency (g/s), and profitability (kJ/s) of seeds. According to the protocol applied, the handling time of all the seeds was different in each bird species; however, the handling time did not affect the preferences of the three birds observed. The results obtained show that the species with larger beaks preferred the most profitable seeds and the seeds that they handled more efficiently, which are the largest seeds in the range of seeds offered. In contrast, the species with the smallest beak preferred seeds of all sizes; therefore, there was no effect of profitability or handling efficiency on the foraging behavior of the smallest bird. This could be due to the fact that the seeds that P. ornata handles more easily would be too small to meet their energy requirements, while the more profitable seeds would take too long to handle. Consequently, this bird could prefer seeds that compensate both variables and that together maximize the efficiency of the diet, given its behavioral flexibility. In contrast, the diet of the larger species, S. multicolor and D. diuca, could be affected in disturbed sites where there is a decrease in larger seeds, that is, those preferred by these birds.
Fil: Estévez, Rocío María. Universidad Nacional de Cuyo. Facultad de Ciencias Exactas y Naturales.

El ganado vacuno consume principalmente plantas de gramíneas, lo que provoca una reducción en la abundancia de sus semillas tanto en pie como en el banco del suelo. Estas semillas son el principal alimento de las aves granívoras en el desierto del Monte central, quienes las prefieren por encima de las herbáceas dicotiledóneas. Se evaluó si el pastoreo genera cambios en la dieta de cinco especies de aves granívoras: Saltatricula multicolor, Diuca diuca, Poospiza torquata, Catamenia analis y Zonotrichia capensis (la cual posee tres subespecies con diferente estatus de residencia). Durante el invierno de 2014 se capturaron aves en algarrobales no pastoreados dentro de la Reserva de Biósfera de Ñacuñán (Mendoza) y en dos estancias aledañas con distinto grado de pastoreo. Se obtuvieron muestras de contenido estomacal por medio de la técnica de lavaje y evacuación del tracto digestivo. Las muestras fueron analizadas cuantificando y clasificando las distintas semillas presentes. Zonotrichia capensis y P. torquata se comportaron como especies plásticas incorporando una mayor cantidad de semillas sub-óptimas a la dieta. Saltatricula multicolor, D. diuca y C. analis mostraron, aunque en distinto grado, una dieta poco flexible basada en la ingesta casi exclusiva de semillas de gramíneas. Las tres subespecies de Z. capensis consideradas en este trabajo mostraron una dieta plástica consumiendo una gran cantidad de ítems sub-óptimos. El pastoreo, al disminuir la abundancia de semillas de gramíneas, provoca variaciones especie-específicas en la dieta de las especies de aves granívoras
Fil: Valdés, Daniela Yanina. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias.

Leydig cells produce testosterone in response to luteinizing hormone (LH) via the cyclic adenosine monophosphate (cAMP)/protein kinase A pathway. Additionally, these cells are responsible for producing insulin-like peptide 3 (INSL3), a peptide hormone that is essential for testicular descent. The insl3 promoter in Leydig cells can be activated by cAMP through the transcription factor Nur77, which has also been shown to regulate the promoters of the steroidogenic enzymes, cyp17 and 3b-hsd. While the mechanism of LH action on testosterone production is well characterized, the effect of LH on insl3 abundance has yet to be shown directly. The MA-10 Leydig cells treated with hCG exhibited a transient and robust increase in nur77 mRNA, while insl3 mRNA abundance remained unchanged. Further, cAMP failed to affect insl3 mRNA, though nur77 mRNA abundance was significantly increased. Inhibition of LH-receptor-linked signal transduction pathways in the presence of hCG implicated multiple signaling networks in the regulation of both insl3 and nur77. Treatment with hCG or cAMP did not affect the abundance of 3b-hsd mRNA. Interestingly, though the MA-10 cell line has been reported to lack CYP17 activity and mRNA and so produce progesterone instead of testosterone, cyp17 mRNA was present and inducible by hCG and cAMP. The addition of hCG, testosterone, nor the combination of hCG and testosterone affected insl3 mRNA abundance. Though hCG consistently increased nur77 mRNA abundance, the addition of testosterone did not enhance the effects of hCG. Collectively, these results indicate that insl3 is regulated by factors other than LH/CG and cAMP in the MA-10 cell line.

Los estudios que involucran la oferta de recursos en el ambiente y el modo en que las especies los explotan, permiten mejorar el entendimiento de esta relación. El presente trabajo propone estudiar la estrategia alimentaria de hábitos alimentarios, especie marsupial que habita en el desierto del Monte y cuya dieta presenta muy poca variabilidad estacional y está compuesta por 70% artrópodos y 30% material vegetal. Los objetivos planteados en esta tesina implican caracterizar y cuantificar la dieta de T. pallidior, describir la variación de recursos alimentarios (plantas y artrópodos) en relación al régimen de precipitaciones, evaluar la dieta en función de la disponibilidad y determinar si existen cambios estacionales en la selección de dieta y amplitud de nicho. El trabajo fue llevado a cabo en la Reserva de Biósfera Ñacuñan, Santa Rosa, Mendoza. Se tuvieron en cuenta muestreos realizados durante 2014 y 2016.
Fil: Sánchez Dómina, Andrea Rosarito. Universidad Nacional de Cuyo. Facultad de Ciencias Exactas y Naturales.

Anthropogenic provisioning of water (water developments) to enhance abundance and distribution of wildlife is a common management practice in arid regions where water is limiting. Despite the long-term and widespread use of water developments, little is known about how they influence distribution, competition dynamics, and behavior of native species. To elucidate the potential influences of water developments on native species, we tested hypotheses concerning the occurrence and behavior of native kit foxes (Vulpes macrotis). First, we tested the indirect effect of water hypothesis (IEWH) which proposes that water developments negatively affect the arid-adapted kit fox by enabling a water-dependent competitor (i.e., coyote; Canis latrans) to expand distribution in arid landscapes. We tested the two predictions of the IEWH (i.e., coyotes will visit areas with water more frequently and kit foxes will avoid coyotes) and evaluated relative use of water by canids in the Great Basin and Mojave Deserts from 2010 to 2012. We established scent stations in areas with (wet) and without (dry) water and monitored visitation by canids to scent stations and water sources using infrared-triggered cameras. There was no difference in the proportions of visits to scent stations in wet or dry areas by coyotes or kit foxes at either study area. There was no correlation between visits to scent stations by coyotes and kit foxes. Visitation to water sources was not different for coyotes between study areas, but kit foxes visited water sources more in Mojave than Great Basin. The intense visitation to water by kit foxes in Mojave challenges our understanding that this species does not readily drink water. Our results did not support the IEWH in the Great Basin or Mojave Deserts for these two canids. Second, we tested three hypotheses that have been proposed to explain spatial variation in vigilance behavior. The predator-vigilance hypothesis (PVH) proposes that prey increase vigilance where there is evidence of predators. The visibility-vigilance hypothesis (VVH) suggests that prey increase vigilance where detection of predators is impeded or visibility is obstructed. The refuge-vigilance hypothesis (RVH) proposes that prey may perceive areas with low visibility (greater cover) as refuges and decrease vigilance. We evaluated support for these hypotheses using the kit fox, a solitary carnivore subject to intraguild predation, as a model. From 2010 to 2012, we used infrared-triggered cameras to record video of kit fox behavior at water developments in the Mojave Desert. The RVH explained more variation in vigilance behavior of kit foxes than the other two hypotheses (AICc model weight = 0.37). Kit foxes were less vigilant at water developments with low overhead cover (refuge) obstructing visibility. Based on our results, the PVH and VVH may not be applicable to all species of prey. Solitary prey, unlike gregarious prey, may use areas with concealing cover to maximize resource acquisition and minimize vigilance.

Membres d’une communauté religieuse fondée au 15éme siècle dans le désert de Thar, les Bishnoï sont de nos jours environ 900 000 et résident encore majoritairement dans cette région du Rajasthan. Etablie originellement sur vingt-neuf préceptes dont plusieurs codifient notamment les relations aux autres vivants, animaux et végétaux, leur doctrine religieuse prône une éthique de vie en accord avec ces préceptes, leur ethnonyme « Bishnoï » signifiant littéralement vingt-neuf, bish : 20, noï : 9. Aujourd’hui, les Bishnoï voient leurs valeurs, leurs représentations et leurs pratiques remises en question par tout un ensemble de facteurs tant socio-économiques qu’écologiques. Avec en filigrane une réflexion sur les ruptures et les continuités dans la transmission de leur doctrine et de ses 29 préceptes, cette thèse interroge les relations et les interactions entre les Bishnoï, les animaux et les arbres de leur environnement, les revendications qui y sont liées ainsi que leurs influences sur les pratiques à la fois idéelles et matérielles de la communauté actuelle. Des pratiques (tout comme les références dogmatiques qui s’y attachent) qui ont pour effet de définir l’identité de ses membres à leurs propres yeux et à ceux du monde extérieur
Members of a religious community founded in the 15th century in the Thar desert, the Bishnoi number about 900 000 today, the majority of whom still live in the Rajasthan region. Originating from 29 precepts, several of which codify relationships to other living beings, animal and vegetal, their religious doctrine upholds a life ethic in accordance with these precepts, their ethnonym "Bishnoï" literally meaning twenty-nine, bish: 20, noï: 9. Today the Bishnoi see their values, representations and practices being questioned by a number of socio-economic and ecological factors. In addition to a look into the ruptures and continuities of the transmission of their doctrine and its 29 precepts, this thesis examines the relationships and interactions between the Bishnoi and the animals and trees in their environment, the demands resulting from them, as well as influences on both material and immaterial practices of the present-day community. Practices (along with their related dogmatic references) that have the effect of defining community members’ identity to themselves and to those of the outside world

El presente estudio busca evaluar otros aspectos de la capacidad de adecuación en Graomys griseoflavus. La hipótesis es que esta especie es capaz de ajustar su fenotipo ante las variaciones estacionales en la disponibilidad de agua, mediante la flexibilidad de rasgos fisiológicos. Para evaluar esto se midió la pérdida total de agua evaporativa (PTAE) y el consumo de oxígeno (TMB) con un equipo derespirometría. Se calcularon variables relacionadas con el balance hídrico como la producción de agua metabólica (PAM) y el índice de eficacia del mantenimiento del balance hídrico (PAM/PTAE), comparando animales de una población entre las estaciones seca y húmeda. Encontramos una disminución en PTAE y un aumento en PAM/PTAE en la estación seca; y una tasa metabólica basal sin diferencias estacionales. Los resultados sugieren que la flexibilidad de rasgos fisiológicos es clave para enfrentar los desafíos temporales en el Desierto del Monte, permitiéndole a G. griseoflavus ahorrar agua en la estación seca y manteniendo su metabolismo ante la demanda energética por las bajas temperaturas de esta estación.
Fil: Coronel, Betiana Melisa. Universidad Nacional de Cuyo. Facultad de Ciencias Exactas y Naturales.

The dark kangaroo mouse, Microdipodops megacephalus, is a sensitive species in the Great Basin Desert. This thesis explores the structure of desert rodent communities of the Great Basin to better understand M. megacephalus' place in the community and the conditions that promote large and stable populations. To determine community structure, I used nestedness analysis to evaluate 99 communities of nocturnal granivorous rodents. I found that the community structure was non-random, indicating the existence of assembly rules and ecological constraints. I also found that M. megacephalus was the second most vulnerable species in the community. To explore the correlation between species diversity and relative abundance, I performed regression analyses on M. megacephalus and five commonly co-occurring species of the nocturnal granivore guild: Perognathus longimembris (little pocket mouse), Perognathus parvus (Great Basin pocket mouse), Dipodomys ordii (Ord's kangaroo rat), Dipodomys microps (chisel-toothed kangaroo rat), and Peromyscus maniculatus (deer mouse). Results showed a positive correlation between rodent species diversity and relative abundance for M. megacephalus, P. longimembris, P. parvus, and D. microps, and a negative correlation for D. ordii and P. maniculatus. To further understand community composition, I ran interspecific association analyses based on presence-absence data for the six species using chi-square to determine strength of interspecific associations. I found positive interspecific associations between M. megacephalus and P. parvus, between P. longimembris and P. parvus, between P. longimembris and D. microps, and between D. microps and P. maniculatus, and a negative association between P. longimembris and P. maniculatus. A species cluster dendogram with respect to sites in common further supports the interspecific association results. A site cluster dendogram with respect to species abundances implies that dune habitat promotes diversity but not uniformity. All results indicate that M. megacephalus is more abundant and stable at sites with high species richness. The results also provide evidence for the existence of assembly rules, competition, and niche partitioning in desert rodent communities.

La vegetation des oueds est etudiee a deux echelles spatiale: la region du desert oriental septentrional d'egypte (3010'n a 2610'n et 3050'e a 3230'e) et un secteur de l'oued sannur (29104n ; 3128'e). A l'echelle regionale, quatre groupements s'individualisent au sein des gradients climatiques nord/sud (precipitations et temperature moyenne annuelle) et nord-ouest/sud-est (evapotranspiration). Un gradient biogeographique se surimpose a cette description, avec des especes mediterranneennes au nord et des especes soudano-angolanes au sud, le fond commun etant saharo-arabique. A l'echelle d'un secteur de l'oued sannur ou la frequence des crues est estimee a sept ans, les especes perennes s'organisent en cinq groupes. La geomorphologie et la granulometrie de surface expliquent une partie de la structure de la vegetation: les especes sont liees au chenal ou aux rives et terrasses d'une part, a une granulometrie de surface fine ou a des zones plus grossieres d'autre part. Les especes annuelles ephemerophytes constituent une synusie ombrique en relation avec les precipitations hivernales et atteignent un maximum de recouvrement au mois de mars. Leur repartition depend essentiellement de la granulometrie dominee par des particules fines. D'une echelle spatiale a l'autre, le poids des facteurs expliquant la structure de la communaute vegetale peut etre different. A l'emboitement des echelles spatiales peut correspondre un emboitement des facteurs mesologiques explicatifs, parmi eux, certains seront pertinents a une echelle donnee et d'autres a plusieurs niveaux

Dr. Eleine Mad är Madeleine Jacobsssons talesperson för dom vetenskapliga och paranormala upptäckter som uppstår i hennes världar. Hon beskriver innehåll, teknik och estetik utifrån ett kategoriseringssytem där konsten delas upp som olika typer av komponenter och därefter avkodas dessa allteftersom. För att förstå intuitionens inblandning i arbetsprocessen omförvandlas den till tre separata roller av en Sökare, Samlare och Myntare. Med rollerna försöker jag beskriva på vilka sätt som intuitionen är till gagn eller av förödelse för det konstnärliga arbetet. Sagan om M handlar om en grodlik karaktär, Delop, som lämnar sin hemplanet för att uppsöka andra världar. I sitt sökande hittar Delop ett folkslag vars syn och levnadssätt skiljer sig från hennes erfarenheter av “verkligheten” såsom hon lärt sig att överleva i den.
Dr. Eleine Mad is Madeleine Jacobsson's spokesperson for the scientific and paranormal discoveries that arise in her worlds. She describes content, tecniques and aesthetics based on a categorization system where art is divided into different types of components and then decoded as they go. To understand the intuition's involvement in the work process, it is transformed into three separate roles by a Seeker, Collector and a Myntare(In swedish language the one who is a "myntare" -is verbally declaring a concept or term). With these roles I try to describe in what ways intuition is beneficial or devastating to the artistic work. The story of M is about a frog-like character, Delop, who leaves the home planet to seek out other worlds. In her search, Delop finds a world whose views and lifestyles differ from her experiences of "reality" as she learned to survive in it.

Recorded sound and image material of the presentation is available for private use.

Eremitalpa granti namibensis is a small blind subterranean insectivore (Chrysochloridae) endemic to the Namib Desert sand dunes. This study of the biology and ecology of the Namib mole assesses its adaptive strategies for survival in a harsh environment. Major areas of study include feeding ecology, movement patterns, home range, activity, thermoregulation and water metabolism. Diet of free-living moles was assessed through stomach content analysis while qualitative and quantitative descriptions of surface foraging paths related searching behaviour to resource abundance and distribution. Moles opportunistically fed on termites, a sedentary prey resource occurring in patches of high concentrations while non-random surface locomotion minimised foraging costs. Population density and home range utilisation were studied by following surface trails and capture mark and recapture. Population density was low but stable and home range size large. No permanent nests or burrows were found while the pattern of home range utilisation was nomadic but circumscribed. Although ranges overlapped, a system of mutual avoidance limited encounters with neighbouring animals. Activity phasing was examined in the field and in the laboratory. Free-living moles were almost exclusively nocturnal while captive moles were active day and night. These findings are discussed in relation to prey availability, predator pressure and avoidance of diurnal extremes. Light and temperature appeared to be important cues for daily onset and cessation of activity. Aspects of thermoregulation examined under laboratory and field conditions revealed high thermal conductance, a low basal metabolic rate and poor thermoregulatory abilities. Factors suggested to have selected for these traits are the gaseous regime of the sand in which moles burrow and the need to minimise energy expenditure in an energy sparse environment. Laboratory and field studies employing isotopic dilution of energy and water methods e xamined the metabolism ability of moles to survive on an insect diet without drinking water. Water independence was achieved through efficient renal function while low rates of energy usage and torpor were further effective in reducing overall water requirements. In summation, a broad overview of adaptive radiation in Namib moles compared to other subterranean mammals is discussed.
Thesis (Ph.D.)-University of Natal, Pietermaritzburg, 1989.

The negative consequence of recent climate change on the Earth’s biodiversity has become more evident in recent years. Some animals, due to insularity or habitat fragmentation, are unable to shift their ranges altitudinally and latitudinally. Vulnerable species need to rely on behavioural and, more importantly, physiological responses in order to persist through present climatic changes. It has therefore become more obvious that physiological responses of individuals need to be incorporated into predictive models of the responses of mammals to accelerated climate change. The primary purpose of this study was to test the ‘Hyperthermic Daily Torpor’ hypothesis proposed recently by Lovegrove et al., (in press). The hypothesis suggests that, based on albeit limited evidence, some small mammals may be capable of hyperthermia induced hypometabolism equivalent to that experienced during torpor and hibernation in response to cold temperatures. These authors argue that such hyperthermic hypometabolism should reduce the risk of entry into pathological hyperthermia and also reduce the rate of water loss driven by heat-induced evaporative cooling. The reaction norms of desert mammals have been selected to be adaptive over a wide range of climatic conditions due to the unpredictability of their habitat. Thus, they are good models for testing the reaction norms that may be expressed in response to accelerated climate change. We therefore tested our hypothesis using two presumably heat-adapted desert rodents; the Namaqua rock mouse, Aethomys namaquensis, and the pygmy rock mouse, Petromyscus collinus, as model species. We used indirect respirometry to measure metabolic rate at high ambient temperatures. We progressively exposed the animals to high temperatures to induce thermal tolerance and thus minimize the risks of lethal hyperthermia. We also measured subcutaneous and core temperatures, using temperature-sensitive PIT tags (BioTherm Identipet) and modified iButtons (Maxim Integrated), respectively. A. namaquensis displayed the capacity for hyperthermia-induced hypometabolism (Q10 79 = 1.27 ± 1.61) whereas the P. collinus did not (Q10 = 2.45 ± 1.41). The implications of such a physiological response in A. namaquensis are crucial in terms of its capacity to minimize the risks of lethal, pathological hyperthermia. Recent models of endothermic responses to global warming based on ectothermic models predict a dichotomy in the thermoregulatory responses of mammals to high temperatures. This study, to our knowledge, provides some of the first data on these interspecific variations in the thermoregulatory responses of mammals to high temperatures. However, the different physiological responses to hyperthermia between these two species cannot be meaningfully interpreted without phylogenetically independent comparisons with other species, that is, a more expansive interspecific analysis. Nonetheless, we provide some autecological sketches to assist in future multivariate interspecific analyses. Physiological differences between captive or captive-bred and free-ranging mammals preclude the extrapolation of our findings to free-ranging mammals. It is almost impossible to collect MR data in the field, although a few authors have successfully done so, and it is often not feasible to collect Tb data in small free-ranging mammals. Most studies have therefore made use of externally-mounted temperature-sensitive data loggers in order to collect Tskin data as a proxy for Tcore data in free-ranging mammals. However, misleading gradients between Tskin and Tcore can occur if data loggers are placed too close to major-heat producing tissues and the effects of the external environment on these data loggers may result in large Tskin – Tcore gradients. The second objective of this thesis therefore was to test the validity of using subcutaneous temperatures (Tsub) from subcutaneously injected temperature-sensitive PIT tags as a proxy for Tcore using the Namaqua rock mouse, Aethomys namaquensis. We found that the difference between Tcore and Tsub was minimal (~ 0.34˚C) within the thermoneutral zone (TNZ) with slight, non-significant, differences outside the TNZ. There was a tendency for Tsub to underestimate Tcore below thermoneutrality and overestimate it above thermoneutrality. We attributed these differences to the various heat loss and heat gain mechanisms activated in response to heat and cold stress in order to maintain a setpoint Tb. Nevertheless, we found that the Tcore – Tskin differential never exceeded 1.59˚C above the wide 108 range of Tas (5˚ – 41˚C) measured. Thus, we can conclude that subcutaneous temperatures provide a reasonably reliable proxy for core temperature in small mammals.
Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2012.

The endangered Snow leopard (Panthera uncia) inhabits the high mountain regions through central Asia and is subjected to numerous threats including poaching for traditional Chinese medicine, retribution killing for preying on domestic stock, and habitat fragmentation. However the occurrence and impact of disease on snow leopard populations is unknown. As emerging infectious diseases of wildlife can be an insidious yet important cause of population decline due to mortality or reproductive failure, my study aimed initially to gain knowledge of pathogens circulating among wild and domestic hosts in this region. I used a broad One Health approach to survey a range of species to collect data on disease occurrence that would be useful in improving human and livestock health, as well as snow leopard conservation. This study is set in the Tost Mountains of the South Gobi Desert of Mongolia and was prompted due to the unexplained deaths of four snow leopards detected within a short timeframe during an ecological study by members of the Snow Leopard Trust. However, investigating disease occurrence in remote, rare and endangered species is a challenge due to inaccessibility of sites, difficulty of capture, and processing samples without facilities. A One Health approach uses multidisciplinary expertise such as ecological, medical and veterinary, to understand host, pathogen and environmental disease factors. This approach is especially useful for diseases that transfer between people, domestic animals and wildlife. As snow leopards are a rare and elusive species, my surveys were aimed at assessing pathogens circulating in snow leopards as well as in sympatric wild and domestic animals. I collected samples from the following hosts: snow leopards – the target species; rodents which are ubiquitous over the study area and are a suitable sentinel species; ibex which are a native ungulate and natural prey species of the snow leopard; domestic goats which are also a prey species of the snow leopard; free-ranging domestic dogs which interact with the goats. The local indigenous people interact with all these species including snow leopards, mostly via retribution killing. Water samples were also collected from waterholes and wells, which are communal meeting places as drinking sources for all species, hence enabling pathogen exchange. Samples collected included blood samples, faecal samples or rectal swabs and ectoparasites if present. These samples were transported to laboratories in Sweden and Belgium where I conducted diagnostic assays for zoonotic pathogens that are present in other regions of Mongolia and impact the health of humans and animals. I used enzyme- linked immune assay (ELISA), polymerase chain reaction (PCR) and next-generation sequencing (NGS) for pathogens including Coxiella burnetii, Toxoplasma gondii, Leptospira spp., Brucella spp., Yersinia pestis and tick borne encephalitis virus. Serovars of Leptospira were elucidated using microscopic agglutination tests (MAT). The dog blood samples were also tested for canine distemper virus. Ticks, faeces, rectal swabs and water were tested for bacteria, Echinococcus, Giardia and Cryptosporidium using PCR and NGS. Health records for humans and animals in the region were not available so, in addition to testing animal samples, I used questionnaire surveys to obtain information on perceptions of the herders concerning health of their families, their domestic animals and wildlife. Questions also assessed preventative health management and treatments used. Over three field trips I caught and sampled twenty snow leopards, 177 rodents (8 species), 41 dogs and 270 goats. I also sampled 11 waterholes/wells, and preserved 18 ticks, hundreds of fleas and collected faecal samples from ibex. Most animals that were sampled and examined clinically appeared in good health, but the serosurvey revealed a moderate to high level of exposure to serious pathogens: C. burnetii, T. gondii and Leptospira spp. There were no published reports of human infections with these pathogens in the study area, which is likely due to a lack of testing. Snow leopards had the highest prevalence of C. burnetii antibodies (25%), followed by rodents (16%), dogs (10%) and goats (9.5%). Goats had the highest prevalence of T. gondii antibodies (90%), dogs (66%), snow leopards (20%) and rodents (16%). Rodents had the highest prevalence of Leptospira spp. (34%), followed by snow leopards (20%) and dogs (5%). Serovars interrogans Australis was identified in the rodents and snow leopards and interrogans Ictohaemorrhagiae was identified in the rodents and dogs. Other serovars were also present from the results of the ELISA but did not match those listed in the MAT panel, so could not be identified. Goats were not tested for infection with leptospirosis. Brucella was not identified in the goats even though it occurs at high prevalence in stock in the rest of Mongolia where it is a large health and economic concern. In rodents, the zoonotic Puumala and Seoul hantavirus were identified for the first time in Mongolia. Analysis of data from rodents showed the pathogens detected (C. burnetii, T.gondii, Hanta virus and Leptospira spp.) differed significantly in prevalence, with a strong year effect driven mainly by Leptospira, which increased in prevalence across the three year study period. Toxoplasma gondii differed slightly in prevalence among rodent species. There was no significant difference in prevalence of interaction of pathogens among years or rodent species. Poor health was detected in goats with 10 out of the 14 goats tested via haematology and biochemistry being anaemic with haematocrits less than 20%. Haematology and biochemistry values for the other animal species appeared normal. I established haematology and biochemistry reference tables for two rodent species - red-cheeked ground squirrels and jerboas. Water samples were negative for serious pathogens. Fleas were negative for Yersinia pestis. However, ticks were positive for several genera of potential zoonoses, including Anaplasma, Bacillus, Coxiella, Clostridia, Francisella, Rickettsia, Staphylococcus, Streptococcus and Yersinia. Faecal samples were also positive for genera of potentially zoonotic bacteria including those listed above plus Bacteroides, Bordetella, Campylobacter and Enterococcus. Results from the two questionnaire surveys revealed the main reported illness in people were colds and flu. However, the local doctor also reported hepatitis as common. She also said that the local people contracted brucellosis whereas I did not identify this pathogen in their livestock. The herders thought their main loss of stock was from predation, with wolves identified as the main predator and snow leopards as the second. Other causes of stock loss perceived as important were adverse climatic conditions such as drought or severe winters while infectious disease was not a concern. Results from these surveys also highlighted gaps in health care for humans and livestock, especially around vaccination and parasite treatments. In summary, I found that snow leopards and other wild and domestic animals within the study area tested positive for previous exposure to several important zoonotic pathogens. These pathogens were likely circulating among species via contamination of pasture and via predation and have potential to cause illness and reproductive loss. However, I detected no adverse effects on the health of the animals due to infection with these pathogens, and observed no related mortality or illness during my field trips. Hence the deaths of the four snow leopards that were the impetus for my study have not been explained, and monitoring and surveillance of this population should continue. My findings on wildlife and domestic animal pathogens have relative importance to improving productivity of livestock and the health of the nomadic herders. I recommend improving the health of goats through vaccination and anti-parasite programmes, which will improve their fecundity and survival and thus increase herder income. These programmes will also have flow-on effects to improve the health of the native ungulates that share the grazing areas by decreasing the risk of pathogen transfer between them and also to the snow leopards that prey on them. Demonstrating the importance of herd health may also help mitigate herder wildlife conflict as increased productivity could decrease the perceived importance of predation on herd numbers. Coxiella burnetii and Leptospires spp are a likely cause of illness in people, despite the lack of reported diagnoses. As rodents had a moderate prevalence of all pathogens tested and inhabit the gers of the local people, it is important to raise awareness of the risk of pathogen transfer to people via rodent excrement contaminating stored food and eating utensils. Risk of human exposure to pathogens during goat slaughter can also be reduced via improved hygiene practices. By identifying pathogens with broad host ranges in a variety of species in this remote mountainous region, my study provides the basis for understanding health risks to wildlife, domestic animals and humans. Consideration of likely transmission routes for pathogens between species can inform current recommendations to improve health, productivity and hence conservation, of the endangered snow leopard – The Ghost of the Mountain.

abstract: This dissertation considers the potential of desire to protect humans, animals, and the environment in the biopolitical times of late capitalism. Through readings of recent South African Literature in English from a postcolonial ecocritical perspective, this project theorizes desire as a mode of resistance to the neocolonial and capitalist instrumentalization of communities of humans and nonhumans, where they are often seen as mere "resources" awaiting consumption and transformation into profit. Deleuze and Guattari posit this overconsumption as stemming in part from capitalism's deployment of the psychoanalytic definition of desire as lack, where all desires are defined according to the same tragedy and brought into a money economy. By defining desire, capitalism seeks to limit the productive unconscious and attempts to create manageable subjects who perform the work of the capitalist machine--subjects that facilitate the extraction of surplus value and pleasure for themselves and the dominant classes. Thinking desire differently as positive and as potentially revolutionary, after Deleuze and Guattari, offers possible resistances to this biopolitical management. This different, positive desire can also change views of others and the world as existing solely for human consumption: views which so often risk bodies towards death and render communities unsustainable. The representations of human and animal desires (and often their cross-species desires) in this literature imagine relationships to the world otherwise, outside of a colonial legacy, where ethical response obtains instead of the consumption of others and the environment by the dominant subjects of capitalism. This project also considers other attempts to protect communities such as animal rights, arguing that rethinking desire is a necessary corollary in the effort to protect communities and lives that are made available for a "non-criminal putting to death" since positive desire precedes the passing of any such laws and must exist for their proper administration. These texts often demonstrate the law's failures to protect communities through portraying corrupt officials who risk the communities they are charged with protecting when their protection competes with government officials' personal capitalist ambitions. Desire offers opportunities for imagining other creative options towards protecting communities, outside of legal discourse.
Dissertation/Thesis
Doctoral Dissertation English 2014

abstract: Human-inhabited or -disturbed areas pose many unique challenges for wildlife, including increased human exposure, novel challenges, such as finding food or nesting sites in novel structures, anthropogenic noises, and novel predators. Animals inhabiting these environments must adapt to such changes by learning to exploit new resources and avoid danger. To my knowledge no study has comprehensively assessed behavioral reactions of urban and rural populations to numerous novel environmental stimuli. I tested behavioral responses of urban, suburban, and rural house finches (Haemorhous mexicanus) to novel stimuli (e.g. objects, noises, food), to presentation of a native predator model (Accipiter striatus) and a human, and to two problem-solving challenges (escaping confinement and food-finding). Although I found few population-level differences in behavioral responses to novel objects, environment, and food, I found compelling differences in how finches from different sites responded to novel noise. When played a novel sound (whale call or ship horn), urban and suburban house finches approached their food source more quickly and spent more time on it than rural birds, and urban and suburban birds were more active during the whale-noise presentation. In addition, while there were no differences in response to the native predator, rural birds showed higher levels of stress behaviors when presented with a human. When I replicated this study in juveniles, I found that exposure to humans during development more accurately predicted behavioral differences than capture site. Finally, I found that urban birds were better at solving an escape problem, whereas rural birds were better at solving a food-finding challenge. These results indicate that not all anthropogenic changes affect animal populations equally and that determining the aversive natural-history conditions and challenges of taxa may help urban ecologists better understand the direction and degree to which animals respond to human-induced rapid environmental alterations.
Dissertation/Thesis
Doctoral Dissertation Biology 2018

abstract: The impact of urbanization on wildlife is becoming an important topic in conservation. However little is known concerning the proximate mechanisms involved which enable some species to persist in cities, while others perish. Adapting to novel city environments requires individuals to maintain a functional physiological response to stressful stimuli, while concurrently using the necessary resources (food) needed to persist. A primary function of the stress response is the mobilization of intrinsic energy resources, and thus both requirements (energy and stress) are explicably linked. This dissertation investigates the interaction of energetic reserves and the physiological stress response in a native bird species, the Curve-billed Thrasher, within the context of this species' colonization of Phoenix, Arizona. This research uses a combination of comparative studies, statistical modeling, and experimental approaches conducted in field and captive settings to demonstrate how urban and desert populations of these species differ in energetic state and stress physiology. These studies reveal that the current energetic status of an individual bird influences the secretion of glucocorticoids (primary stress hormones) and can alter how energy reserves are used for gluconeogenesis to produce energy during acute stress. In addition, this research also identifies how differing levels of a hypothalamic neuropeptide (vasotocin) may play a role in mediating differences in stress physiology between populations. The quantity of food available and even temporal variability in its abundance may alter how native birds respond to stress. Increased body condition offsets the costs of maintaining the stress response in urban areas.
Dissertation/Thesis
Ph.D. Biology 2010

Nous nous pencherons sur les travaux du jeune Heidegger afin de montrer que, s’il affirme dans Être et temps que les animaux ne sont ni chose, ni Dasein, mais participent d’un énigmatique mode d’être propre – le « simplement vivant », ce qui ne fait « rien de plus que vivre » – cela constitue un revirement dans la pensée heideggérienne. Dans les travaux qui préparent la rédaction de Sein und Zeit, l'animal avait toujours été considéré comme un être qui a un monde, comme un être auquel nous devons reconnaître le mode d'être du Dasein. En s’appuyant sur l’interprétation phénoménologique d’Aristote qu’il présente dans ses cours de 1919 à 1926, nous montrerons que les structures fondamentales de l'être-au-monde ont été élaborées sur le fond des capacités propres à la vie animale que sont l’affection (pathos), la perception (aisthēsis), la discrimination (krinein), la mobilité (kinesis kata topon) et le désir (orexis).
Our investigation of young Heidegger’s work aims at showing that, if Being and Time states that animals are neither mere things, neither Dasein, but have their own puzzling mode of being – “mere life”, which does not exist, but simply lives – this constitutes a reversal in Heidegger’s way of thinking. In the works that prepared the way towards Sein und Zeit, animal life was always presented as being-in-a-world, as a being to which we must ascribe Dasein’s way of being. With the help of Heidegger’s phenomenological interpretations of Aristotle presented between 1919 and 1926, we will show that the basic features of being-in-the-world that will become Being and Time's existential structures were developed on the basis of capacities belonging to animal life : affection (pathos), perception (aisthēsis), discrimination (krinein), mobility (kinesis kata topon) and desire (orexis).

abstract: Modified and artificial water sources can be used as a management tool for game and non-game wildlife species. State, federal, and private agencies allocate significant resources to install and maintain artificial water sources (AWS) annually. Capture mark recapture methods were used to sample small mammal communities in the vicinity of five AWS and five paired control sites (treatments) in the surrounding Sonoran desert from October 2011 to May 2012. I measured plant species richness, density, and percent cover in the spring of 2012. A Multi-response Permutation Procedure was used to identify differences in small mammal community abundance, biomass, and species richness by season and treatment. I used Principle Component Analysis to reduce 11 habitat characteristics to five habitat factors. I related rodent occurrence to habitat characteristics using multiple and logistic regression. A total of 370 individual mammals representing three genera and eight species of rodents were captured across 4800 trap nights. Desert pocket mouse (Chaetodipus penicillatus) was the most common species in both seasons and treatments. Whereas rodent community abundance, biomass, and richness were similar between seasons, community variables of AWS were greater than CS. Rodent diversity was similar between treatments. Desert pocket mouse abundance and biomass were twice as high at AWS when compared to controls. Biomass of white-throated woodrat (Neotoma albigula) was five times greater at AWS. Habitat characteristics were similar between treatments. Neither presence of water nor distance to water explained substantial habitat variation. Occurrence of rodent species was associated with habitat characteristics. Desert rodent communities are adapted for arid environments (i.e. Heteromyids) and are not dependent on "free water". Higher abundances of desert pocket mouse at AWS were most likely related to increased disturbance and debris and not the presence of water. The results of this study and previous studies suggest that more investigation is needed and that short term studies may not be able to detect interactions (if any) between AWS and desert small mammal communities.
Dissertation/Thesis
M.S. Applied Biological Sciences 2013

Tese de mestrado, Ecologia Marinha, Universidade de Lisboa, Faculdade de Ciências, 2020
A cada ano, o ambiente marinho e costeiro é progressivamente mais afetado pelos efeitos nocivos do lixo marinho, representando uma ameaça para o ecossistema marinho e para a sua biodiversidade. O presente estudo analisou, pela primeira vez, a prevalência, abundância e características dos resíduos antropogénicos, com ênfase nos detritos plásticos, em colónias de gaivota-de-patas-amarelas (Larus michahellis) no arquipélago da Madeira. Um total de 228 amostras de egagrópilas, ninhos e excrementos foram recolhidas em colónias mais próximas de zonas urbanas (ilha da Madeira) e em colónias mais isoladas (ilhas Desertas), no qual se verificou a presença de resíduos antropogénicos em 65,8% e 57,0% das amostras analisadas para cada local, respetivamente. Os resultados obtidos evidenciam a presença de detritos plásticos em todos os tipos de amostra para ambos os locais de amostragem, bem como uma maior prevalência e abundância de detritos plásticos detetados na ilha da Madeira. Verificaram-se diferenças significativas entre locais para as características dos detritos plásticos, nomeadamente nas categorias, cores e tamanhos. O estudo evidencia, ainda, diferenças entre os três tipos de amostra. As cores mais predominantes foram o verde e o branco nas egagrópilas da Madeira e o azul e o branco nas Desertas; o branco nos ninhos; o azul e o preto nos excrementos. Cordas e filamentos, muito semelhantes aos materiais de pesca, foram as categorias de plástico mais observadas, o que indica uma pressão desta atividade nos locais de amostragem. Dos 169 detritos de plástico identificados através da técnica de espectroscopia FTIR, obteve-se uma grande variedade de polímeros, dos quais o PE (25,2%), PET (16,6%) e PVC (13,3%) foram os mais frequentes. São necessárias mais investigações futuras sobre a interação dos detritos plásticos com outras espécies de aves marinhas no arquipélago da Madeira em diferentes intervalos temporais, de forma a compreender os potenciais efeitos destes resíduos nos organismos marinhos deste ecossistema insular.
Each year, marine and coastal ecosystems are progressively affected by the harmful effects of marine litter, posing a threat for the marine ecosystem and its biodiversity. The present study analyzed, for the first time, the prevalence, abundance and characteristics of anthropogenic debris, focused on plastics, in colonies of yellow-legged gull (Larus michahellis) in Madeira archipelago. A total of 228 samples of pellets, nests, and feces were collected in colonies close to urban hotspots (Madeira Island) and more isolated colonies (Desertas Islands), of which 65,8% and 57,0%, respectively, verified the presence of anthropogenic debris. The results highlight the occurrence of plastic debris on every type of sample, for both locations, as well as higher prevalence and abundance of plastic debris on Madeira Island’s colonies. Significant differences were found regarding the characteristics of plastic debris found between locations, namely in category, color and size. Moreover, the study underscores significant differences between the three sample types. The predominant colors were green and white for Madeira pellets, blue and white for Desertas pellets; white for nests; blue and black for feces. Rope and filaments, which are very similar to fishing gear, were the most observed categories of plastic, indicating pressure from this activity in both sample sites. From the 169 plastic debris analyzed by FTIR spectroscopy, a large variety of polymer compounds were found, of which the most frequent were PE (25,2%), PET (16,6%) and PVC (13,3%). Further investigation on the interaction between plastic debris and Madeira archipelago’s marine birds on different temporal trends is needed to better understand to what extent these residues affect marine organisms in this insular ecosystem.

This thesis is comprised of two parts: a Studio Research component with accompanying Exegesis (66%), and a Dissertation (33%). The Dissertation provides the historical theoretical component that informs the Studio Research and Exegesis, entitled The Dingo in the Colonial Imagination.This body of work investigates the tensions between humans and animals that share boundaries. It focuses on the terse relations between humans, dingoes and wild dogs in southeastern Australia. Ideological and practical themes emerged through the studio-based and theoretical research, which spans a range of disciplines including art, science, culture and history. At its core is how humans and undomesticated animals share arbitrary boundaries and suffer the transgression of these boundaries. Primary field research informed the studio and theoretical aspects of the project. It involved consultation with individuals and agencies affected by dingoes and wild dogs in interface zones where private and government managed lands intersect. The 30,000 word dissertation traces colonial visual representations of the Australian native dog during the century that spans early European settlement to Federation. It follows perceptions of the dingo as it is imagined and encountered by European settlers. The dingo's guise ranges from scientific curiosity, object of desire, symbol of wilderness, metaphor for a dying race and as an enemy that threatens the social and economic fabric of the colonial project. The studio work amplifies the influence of these colonial perceptions on contemporary attitudes to dingoes. It follows a trajectory of the disappearing dingo in its representational form, to its implied remnant presence within the farmers' psyche. Early studio work explored a range of materials and practices, encompassing sculptural and drawing strategies, and took its cue from a macabre ritual of animal shaming in remote regional Australia, the so-called 'dog trees', that display the carcasses of one or multiple dingoes and wild dogs. The studio work has culminated in a large-scale sculptural installation, designed to pare back the visual language to its essential elements. This work incorporates the dissolution of the dingo form, which becomes absorbed into the personal objects embedded into the farmers' private territory. The poetic objects that form the final sculptural work presented for examination, Lines of desire, become metaphors for the dingo's capacity to survive and unsettle the rural subconscious.

The Philebus is devoted to the question what constitutes the good for a human being. Although Socrates initially favors a life of pure intelligence against the hedonist’s life of pure pleasure, he quickly concedes that some pleasures actually enhance the life of intelligence. In order to determine which pleasures deserve a place in the best life, Socrates undertakes a lengthy investigation into the nature of pleasure. Commentators have long been frustrated in their attempt to uncover a single, unified account that explains in a plausible way the extraordinary variety of pleasures analyzed in the dialogue. I argue that this search for a generic account of pleasure is misguided, because one of the main purposes of Socrates’ division of pleasure is to expose its essentially heterogeneous nature. Pleasures can be bodily or psychic, pure or mixed with pain, truth apt or not, healthy or diseased, and inherently measured or unmeasured, and there are no essential properties which all of these diverse phenomena share. The inclusion of some pleasures in the final ranking of the goods at the end of the Philebus represents a dramatic shift in Plato’s attitude towards certain pleasures, and so it is not surprising that many scholars misinterpret the force of this conclusion. Even in the Republic where the pleasures of reason are favorably compared to the pleasures of spirit and appetite, intellectual pleasures are judged to be more pleasant and real than other pleasures, but they are nowhere judged to be better or praised as genuine goods. In the Philebus, not only are some pleasures unambiguously ranked among the highest goods, but Socrates gives no indication that these pleasures are good only in some qualified or extrinsic way. Instead, certain pleasures make their own positive contribution to the goodness of the best human life, making the mixed life more valuable and choiceworthy than the unmixed life of intelligence.