Dissertations / Theses on the topic 'Animal migration'

Individual specialization refers to individuals using different portions of the total ecological niche of the population. The fact that individuals segregate into different strategies has important implications on ecology, evolution and conservation, which can be even greater than the implications associated to differences among species. Therefore, it is important to know the degree of individual specialization in wild populations and in what dimensions of individuals’ ecological niche it occurs. Similarly, to understand the processes underlying individual specialization, it is key to study intrinsic drivers and environmental conditions that lead individuals to segregate into different portions of the ecological niche. In this thesis, we aimed to delve into the extent of individual specialization in foraging and migration strategies, as well as to provide insights on the intrinsic and extrinsic drivers that shape it. We used two long-lived seabird species, Cory’s (Calonectris borealis) and Scopoli’s (C. diomedea) shearwaters, to study individual specialization in feeding and migratory traits by using stable isotope analyses, global location sensing (GLS) and global positioning system (GPS) loggers. In this thesis, we showed that individuals specialize in several aspects of the ecological niche, namely diet, foraging and wintering grounds, habitat use, daily habits and foraging movements. However, in none of these traits individuals showed high levels of specialization, thus suggesting a stabilizing selection in specialization levels. Regarding intrinsic drivers, our results elucidate that males and females can differ in their degree of individual specialization in diet and foraging movements. These differences were probably driven by a higher use of males on fishery discards. We also showed that the same individual can develop different strategies under different habitats, indicating individual foraging strategies are likely learned with experience when individuals are young and not driven by intrinsic constraints, such as physiological or morphological constraints. Regarding the extrinsic drivers, we provide evidences that resource scarcity is more relevant in driving among-individual variability in foraging movements than resource predictability. Overall, in this thesis we demonstrate that the extent of individual specialization within populations can depend on several intrinsic and extrinsic factors, and that individual specialization is a complex phenomenon that can vary across species and ecological traits. The fact that individuals can develop different strategies independently in different areas indicates a remarkable plasticity that may help them to cope with future natural or anthropogenic changes in the environment.

The adult mammalian kidney forms from the reciprocal interaction between two tissues; the ureteric bud which will form the collecting duct system and the metanephric mesenchyme which will form all the cells in the nephrons. This thesis used ex-vivo embryonic kidney culture to show that during mouse kidney development metanephric mesenchymal cells migrated towards the periphery of the kidney. When this migration is pharmacologically inhibited the Six2 expressing metanephric mesenchyme cells no longer expanded their population and kidney development ceases. LIM kinase, which had been shown to regulate cell migration, when inhibited not only prevented cell migration in both embryonic mouse kidneys and in HK2 cells but also prevented embryonic kidney cells from completing mitosis and caused them to undergo apoptosis. This thesis showed that inhibition of LIM kinase in HK2 cells resulted in the formation of multiple alpha-tubulin foci, multiple centrosomes, the premature dispersal of the cohesin complex protein SMC3 in the absence of a fully formed spindle, and cell death. Thus concluding that active LIM kinase is required for the generation of the mitotic spindle and the appropriate dispersal of SMC3. This thesis furthered the understanding of how the metanephric mesenchyme develops and showed that these cells migrated away from the ureteric bud and this migration is required for further growth of the kidney. This thesis also showed that active LIM kinase is required for the completion of mitosis in both embryonic kidneys and HK2 cells.

Thesis (MSc)--Stellenbosch University, 2014.
ENGLISH ABSTRACT: Introduction Normal cerebral cortex development depends on extensive neuronal migration during embryogenesis, permitting the formation of accurate synaptic circuits and a highly ordered laminar neocortex. The motility of a migrating neuron is achieved by a dynamic microtubule cytoskeleton that alternates between states of stabilization/lengthening and destabilization/shortening. This dynamic instability of the microtubule cytoskeleton is controlled by numerous microtubule-stabilizing and -destabilising proteins that bind directly to microtubules. Autophagy (“self-eating”), a major bulk intracellular degradation system, involves the fusion of autophagosomes with lysosomes, followed by proteolysis and recycling of cellular constituents. Like neuronal migration, autophagy is a microtubule-dependent process. The dynamic microtubule network serves as a track for autophagosomes to be transported to the lysosomes. WDR47 is a protein that is expressed in the brain during development, but of which the function is largely unknown. Novel interactions have recently been identified between Reelin and WDR47 and between the microtubule-destabilising protein superior cervical ganglion 10 (SCG10) and WDR47. These findings suggest that WDR47 may be regulating microtubule-dependent processes such as neuronal migration and autophagy. We hypothesize that WDR47 may play a role in regulating neuronal migration and/or autophagy, and that this regulation may be mediated by a tubulin stability-regulating role of WDR47. Aims and Methods Our aims are to assess the cellular localization of WDR47 in GT1-7 cells and to determine whether WDR47 is able to influence neuronal migration, filopodia extension, surface adhesion, ultra-structure, autophagy, tubulin stability, and tau or SCG10 protein levels. GT1-7 neuronal cells were cultured under normal conditions and transfected with WDR47 siRNA for 24 hours, followed by western blot verification of the knock-down. A 36 hour neuronal in vitro cell migration assay was performed and images of the wound were captured every 6 hours; the migration distances and the wound areas for the different time points were measured and analysed. A 24 hour migration assay was performed, capturing images every hour, and the direction of migration was determined. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were performed to analyse neuronal surface morphology and ultra-structure. Western blot analysis of SCG10, acetylated α-tubulin, Tau, LC3, and Sequestosome 1/p62 (SQTM1) protein levels was performed. Super-resolution structured Illumination microscopy (SR-SIM) three-dimensional (3-D) imaging of WDR47-YFP transfected cells, confocal microscopy of LC3 and acetylated tubulin, co-localization analysis of WDR47 and acetylated tubulin, and fluorescence recovery after photo-bleaching (FRAP) analysis were performed. Results WDR47 siRNA treatment significantly reduced the average migration distance and the migration velocity, resulted in fewer filopodia-like extensions as well as perturbed surface adhesion of migrating neurons, and lead to an increased presence of endoplasmic reticulum (ER) structures as well as an expanded nuclear envelope. LC3-II protein levels were significantly lower with WDR47 siRNA treatment, but were significantly increased with WDR47 siRNA treatment in conjunction with Bafilomycin A1 treatment, indicating increased autophagic flux. SCG10 protein levels were significantly decreased with WDR47 siRNA treatment. SR-SIM and confocal microscopy of WDR47 siRNA treated cells revealed a robust presence of highly convoluted acetylated tubulin in the perinuclear region as well as decreased LC3 fluorescence signal. Confocal microscopy revealed co-localization of WDR47 with acetylated tubulin. - Discussion and Conclusion: The results suggest that WDR47 is involved in regulating neuronal migration, neuronal surface adhesion and filopodia formation, microtubule dynamics, and likely also autophagic flux. Taken together, we propose that WDR47 is regulating microtubule dynamics by facilitating assembly of microtubule-regulating proteins such as SCG10, thereby affecting microtubule-dependent processes such as neuronal migration and autophagy.
AFRIKAANSE OPSOMMING: Inleiding Normale serebrale korteks ontwikkeling is hoogs afhanklik van neuronale migrasie tydens embriogenese, en is belanrik vir die vorming van akkurate sinaptiese netwerke en 'n hoogs geordende laminêre neokorteks. Die vermoё van 'n neuron om te migreer berus op 'n hoogs dinamiese mikrotubulien sitoskelet wat verleng/stabiliseer of verkort/destabiliseer soos tubulien-eenhede begevoeg of verwyder word. Hierdie dinamiese onstabiliteit van die mikrotubulien sitoskelet word beheer deur verskeie mikrotubulien-stabiliserende en - destabiliserende proteïene wat direk bind aan mikrotubuliene. Autofagie ("self-eet"), 'n grootmaat intrasellulêre degradasie stelsel, behels die fussie van autofagosome met lisosome, gevolg deur proteolitiese afbraak van sellulêre organelle en proteine. Soos neuronale migrasie is autofagie 'n mikrotubulien-afhanklike proses. Die dinamiese mikrotubulien netwerk dien as 'n spoor vir die vervoer van autofagosome na lisosome. WDR47 is 'n proteïen wat voorkom in die brein tydens ontwikkeling, maar waarvan die funksie grootliks onbekend is. Interaksies was onlangs geïdentifiseer tussen beide Reelin en WDR47 en die mikrotubulien-destabiliserende proteïen SCG10 en WDR47. Hierdie bevindinge dui daarop aan dat WDR47 n rol speel in die regulering van tubulienstabiliteit en sodoende mikrotubulien-afhanklike prosesse. Ons veronderstel dat WDR47 'n rol kan speel in die regulering van neuronale migrasie en/of autofagie en dat hierdie regulasie moontlik afhanklik is van 'n tubulien-stabiliteit-regulerende rol van WDR47. - Doelwitte en Metodes: Ons doelwitte is om die sellulêre lokalisering van WDR47 in GT1-7 neurone te evallueer en om te bepaal of WDR47 n effek het op neuronale migrasie, oppervlak adhesie en filopodia formasie, ultra-struktuur, autofagie, tubulien-netwerke en -stabiliteit, en Tau of SCG10 proteïenvlakke. GT1-7 neuronale selle is gekweek onder normale omstandighede en vir 24 uur getransfekteer met WDR47 siRNA, gevolg deur verifikasie met Western-blot analise. 'n 36 uur neuronale in vitro sel migrasie toets is uitgevoer en fotos van die wond is elke 6 uur geneem. Die migrasie afstande en die wondareas vir die verskillende tydpunte is gemeet en ontleed. 'N 24-uur-migrasie toets is uitgevoer, 'n foto van die wond is elke uur geneem, en die rigting van migrasie is bepaal. Skandering elektronmikroskopie (SEM) en transmissieelektronmikroskopie (TEM) is uitgevoer om neuronale oppervlakmorfologie en ultrastruktuur te observeer. Western blot analise van SCG10, geasetieleerde α-tubulien, Tau, LC3 en Sequestosome 1/p62 (SQTM1) proteïenvlakke is uitgevoer. Super-resolusie gestruktureerde verligting mikroskopie (SR-SIM) driedimensionele (3-D) beelding van WDR47-YFP getransfekteerde selle, konfokale mikroskopie vir visualisering van LC3 en tubulien, co-lokalisering analise van beide WDR47 en LC3 en WDR47 en tubulien, asook fluorescentie hersteling na foto-bleek (FRAP) analise is uitgevoer. Resultate Die gemiddelde migrasie-afstand en die migrasiesnelheid (μm/min) het beduidend afgeneem met WDR47 siRNA behandeling. SEM analise van WD47 siRNA-behandelde neurone het minder filopodia en veranderde oppervlak adhesie vertoon, en TEM analise het 'n verhoogde teenwoordigheid van endoplasmiese retikulum (ER) strukture, en 'n uitgebreide kernmembraan vertoon. LC3-II proteïenvlakke was beduidend laer met slegs WDR47 siRNA behandeling, maar beduidend hoёr met WDR47 siRNA behandeling in samewerking met Bafilomycin A1 behandeling. Hierdie resultate dui aan op toeneemende autofagie met WDR47 siRNA behandeling. Verder, beduidend laer vlakke van SCG10 proteïenvlakke is waargeneem met WDR47 siRNA behandeling. SR-SIM en konfokale mikroskopie van WDR47 siRNA behandelde selle het 'n robuuste teenwoordigheid van hoogs buigende geasetieleerdetubulien in die area rondom die nukleus, 'n afgeneemde LC3 Bespreking en Gevolgtrekking Die resultate dui daarop aan dat WDR47 betrokke is by die regulering van neuronale migrasie, filopodia vormasie, oppervlak adhesie, mikrotubuliendinamika, en waarskynlik ook autofagie. Ons stel voor dat WDR47 mikrotubuliendinamika afekteer deur die regulering van proteïene soos SCG10, en sodoende mikrotubulienafhanklike prosesse soos neuronale migrasie en autofagie fasiliteer.

The Indian Ocean represents one of the oldest exchange networks connecting South-East-Asia with India, the Arabian peninsula, as far as Africa in the West. Since the beginning of the Common Era, extensive trade between geographically distant and culturally diverse people enabled the transmission of not only new technologies, exotic goods and food items, but also diverse plant and animal species. Although archaeological remains, particularly from the 1st millennium AD, reflect an intensification of maritime connectivity across the Indian Ocean, the exact routes of travel and trade across this vast area in early times are still subject to discussion. This thesis presents different projects that aim to assess the potential of using commensal animals, such as the house mouse Mus musculus, the black rat Rattus rattus, and the Asian house gecko Hemidactylus frenatus, as proxies to infer pathways of human travel and trade. Commensal species are usually small animals, that live in close association with humans and opportunistically exploit their habitat and food sources. Utilisation of these new resources has led to a close relationship between humans and certain species, and thus favoured their global distribution due to translocations through humans. Therefore, genetic analyses from modern and museum samples of the species in question have been employed, and embedded in a phylogeographic approach. This integrative methodology connects genealogy and geography, with the aim to reconstruct evolutionary, demographic, and biogeographic processes that led to the contemporary distribution of genetic lineages of the commensal species and subsequently mirrors travel routes of the humans who carried them. The incorporation of ancient DNA analysis provides a powerful method, not only enabling the detection of source populations, but direct monitoring of their genetic change through time. Given that people have moved them around for a long time, undirected distribution pattern of populations were expected for each species. However, the results demonstrate that several unique and geographically restricted lineages have been identified, reflecting past human-mediated translocation throughout the Indian and Pacific Ocean from the 1st millennium AD onwards.

Zebrafish heart regeneration remains one of the most interesting phenomena of the 21st century. Considering the extremely high rate of deaths due to cardiovascular diseases in the developed countries, 1 out of every 3 people, understanding natural cardiac regeneration would address a worldwide challenge. Even though many aspects of zebrafish heart regeneration have been elucidated, there are still many open questions to be answered. Among these, the work presented here focuses on understanding cell migration mechanisms of cardiomyocytes and epicardial cells during heart regeneration. The first approach involves the development of a cardiomyocyte-specific, photoinducible Cre/lox genetic labeling system and its use in lineage tracing of embryonic cardiomyocytes during heart development and regeneration. By using this method we showed that cardiomyocytes labeled in embryonic hearts survive and contribute to all myocardial layers of the adult zebrafish heart. Moreover, lineage tracing during regeneration showed that only cardiomyocytes immediately adjacent to the injury site contribute to the regeneration, and cardiomyocyte fate is extensively predetermined, with cells from each myocardial layer giving rise to cells that retain their layer identity in the regenerated myocardium. Then, we showed that by coupling this labeling system to three-photon microscopy activation, we can perform prospective labeling, and increase the spatial resolution of our labeling system. Three-photon illumination has been used for in vivo imaging of deep structures, but whether it can be used for photo-activation had never been tested. Here we showed, theoretically and experimentally for the first time, that three-photon illumination is suitable for activating molecules in deep tissues and improving our system in terms of spatial resolution and prospective labeling. The final approach consisted on developing an ex vivo experimental set up in order to investigate physical characteristics of epicardial cell migration during zebrafish heart regeneration. This method allowed us to measure physical features that are essential for cell migration such as migration velocity and traction forces of the epicardial explants obtained from zebrafish hearts. All the approaches developed in this thesis offer new bioengineering tools to study zebrafish heart regeneration, and reveal new insights on this process. Moreover, these techniques present wide applicability to perform lineage tracing of other cell types during zebrafish heart regeneration or in other biological processes.
Los humanos tienen una capacidad muy limitada para regenerar el corazón y, como consecuencia de ello, una de cada tres personas fallece debido a enfermedades cardíacas. En cambio, el pez cebra tiene una enorme capacidad intrínseca para restaurar grandes porciones de su corazón tras un daño, por lo que se ha convertido en uno de los modelos experimentales más usados para investigar la regeneración del corazón. Entender los mecanismos que controlan la regeneración cardíaca del pez cebra permitirá desarrollar estrategias para regenerar el corazón humano y buscar soluciones a estas enfermedades. Basándonos en este gran objetivo, el trabajo que forma el estudio de esta tesis doctoral detalla algunas aproximaciones de bioingeniería dirigidas a estudiar el papel de la migración celular de los cardiomiocitos y de las células del epicardio durante la regeneración del corazón del pez cebra. La primera aproximación es un sistema de seguimiento del linaje de los cardiomiocitos del pez cebra para investigar su destino durante la regeneración cardiaca. Para esto, se desarrolló un sistema de marcado genético de linaje con triple especificidad, de tipo celular, temporal y espacial, que permitió marcar los cardiomiocitos en diferentes partes del corazón. Utilizando esta técnica se demostró que durante la regeneración sólo los cardiomiocitos inmediatamente adyacentes a la lesión contribuyen al miocardio regenerado. A continuación, se utilizó la iluminación multifotón de tres fotones para fotoactivar cardiomiocitos in vivo con el objetivo de aumentar la resolución espacial del marcado genético. En este trabajo se demostró teóricamente y experimentalmente que la iluminación de tres-fotones supera problemas de dispersión y es capaz de realizar la fotoactivación, convirtiéndose en el primer ejemplo donde se consigue utilizar este tipo de iluminación para fotoactivar células in vivo. El uso de la iluminación de tres fotones en combinación con el sistema de marcado genético fotoinducible permitió marcar los cardiomiocitos de embriones de pez cebra de forma prospectiva. Por último, se desarrolló un sistema ex vivo para caracterizar el comportamiento migratorio de las células del epicardio del corazón del pez cebra con el fin de investigar las características físicas de la migración celular durante la regeneración. Este método permitió medir las características físicas esenciales para la migración celular, tales como la velocidad migratoria y las fuerzas de tracción en las células del epicardio.

The ultimate causes of bird migration are largely unknown despite more than a century of research. By studying partially migratory short-distance tropical migrants and by employing comparative methods, some difficulties in testing hypotheses for evolution of migration can be overcome. Using comparative methods I tested the evolutionary precursor hypothesis, a major hypothesis for why migration evolved in some lineages and not in others. The results of this study conflicted with many assumptions and predictions of the evolutionary precursor hypothesis. Most importantly, migratory behavior was not related to diet and habitat in simple ways. The interaction between diet and habitat, as well as consistent associations between flocking behavior and migration suggested that food variability is poorly captured by the surrogates embodied in the evolutionary precursor hypothesis. I then employed comparative methods to studying tropical altitudinal migration. Comparisons of diets and fruit preferences between species pairs showed that migrants are more frugivorous, eat a broader diversity of fruits, and have diets that more strongly resemble their preferences than do residents. Although providing evidence that food limitation plays a role in altitudinal migration, these results do not support the hypothesis that interspecific competition explains variation in migratory behavior. Next, I provided the first test of a predation-based hypothesis to explain altitudinal migration. Migrants breed at higher elevations than where they spend their non-breeding season. Thus, birds may migrate uphill to escape high nest predation risk at lower elevations. Results from this experimental study are largely consistent with this hypothesis, but anomalies between predicted and observed patterns suggest that either migration of lowland birds occurs in response to other factors, or that anthropogenic change has altered the tradeoffs involved in migratory decisions. Finally, I focus on a single migrant species and evaluate (a) two food-based hypotheses to explain the destination of migration movements, and (b) mechanisms underlying intra-specific differences in migratory strategy. Food can explain why Corapipo altera migrate uphill, but not why they migrate downhill. My data on sex bias and body condition leads to a new hypothesis explaining the complete annual cycle of this tropical migrant bird.

Thesis (Ph.D.)--Indiana University, Dept. of Biology, 2006.
Source: Dissertation Abstracts International, Volume: 67-04, Section: B, page: 1801. Adviser: Wayne C. Forrester. "Title from dissertation home page (viewed June 20, 2007)."

There is currently widespread concern about the impact of continuing climate change on the distribution, and ultimately persistence of species across all the major taxa. While much previous work has focussed on using climate envelope models to make projections of the location of potential future suitable climate space for a variety of species, these can at best give an indication of the likely direction and potential magnitude of distributional change. They lack information on spatial population dynamics, dispersal, habitat suitability, local adaptation and inter-specific interactions. The aim of this thesis was to explore how some of these other factors might alter projections regarding species’ distributional change in response to climate change, using both theoretical models, and garden warbler (Sylvia borin) as a model system. A key aspect which has been largely over-looked until very recently is the complex range dynamics which can result from spatial variation in population dynamics, and the impacts of inter-annual variability rather than simply mean climate, both of which can impact extinction risk. Much insight into future impacts of climate change can also be gained through studies of past distributional changes, such as that observed in the British breeding population of garden warbler in the last three decades. In many cases, studies at smaller-scales are necessary to elucidate the mechanisms of climate change impacts and further explore potential synergies with other drivers of ecosystem change such as habitat loss and species invasions. The particular combination of factors which should be included to make projections of distributional change will be species-specific and scale-dependent, therefore modelling exercises should be carefully designed depending on the intended outcome for conservation.

The patterns of human diet and migration of the population of Boğazköy in north-central Anatolia were investigated through the application of carbon (δ13C), nitrogen (δ15N) and sulphur (δ34S) stable isotope analysis of bone collagen. The materials used for this research include human and faunal bone samples dating from the Bronze Age to the Roman period. This is the first isotopic study conducted at Boğazköy and for these time periods in north-central Anatolia. The aim of the research was both to reconstruct the dietary habits and mobility patterns of this community as well as investigating the usefulness of δ34S analysis as a dietary tool in this region of Anatolia. Examining the diet and economy at Boğazköy through an isotopic perspective provides a clearer understanding of the life of the inhabitants of the city and sheds light of the political and sociological changes observed during this period in Anatolia. Analysis across different periods revealed that the Bronze Age stands out with the most enriched δ15N (9.9±0.8‰) and δ34S (12.6±3.0‰) values, suggesting a higher consumption of protein in relation to later periods and/or foreign origin for these individuals. With the exception of the Bronze Age, dietary behaviours were very similar across all phases of occupation and do not differ significantly from those observed at other Anatolian sites. The δ13C (‒18.6±0.4‰) and δ15N (9.0±0.9‰) average values for the Iron Age, Hellenistic and Roman periods suggested a diet predominantly based on C3 terrestrial sources. Variations between individuals, implying the consumption of different levels of animal protein, were not directly connected to sex or age. The δ13C results for several of the domestic animals suggest inclusion of C4 plants in their diets. Slight elevated δ13C values for humans indicates the consumption of these animals or the variability of C3 plant values, which may relate to the aridity of this region. The δ15N results suggest the consumption of low quantities of meat, dairy products and/or the contribution of pulses. The application of δ34S has also provided insight into Boğazköy’s economy by suggesting the use of transhumance as a herding strategy during the Iron Age. The presence of foreigners during the Hittite period is also implied by the δ34S results from the human samples. These indicate a coastal provenance where sea-spray effect was visible; however, the lack of a δ34S baseline data for large regions of Anatolia hinders further interpretation of the results.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Universidade Estadual Paulista (UNESP)
O experimento teve como objetivo avaliar a sobrevivência de larvas infectantes (L3) de Trichostrongylus colubriformis em três espécies forrageiras. Para tal, foram utilizados módulos experimentais constituídos por seis canteiros de 32,4 m2 cada, estabelecidos com as seguintes gramíneas forrageiras: Brachiaria decumbens cv. Australiana, Cynodon dactilon cv. Coast-cross e Panicum maximum cv. Aruana, perfazendo dois canteiros por espécie. Cada canteiro foi dividido em 36 parcelas, de 30 x 30 cm, de forma a permitir seis repetições por espécie e por altura em cada semana de colheita de material. A sobrevivência larval foi avaliada nas quatro estações do ano, sob o efeito de duas alturas de poda das forragens (baixa, 5 cm e alta, 30 cm). A poda foi realizada imediatamente antes da deposição das fezes. Ocorreram quatro deposições de fezes, uma a cada estação do ano. A colheita das fezes e da forragem foi realizada uma, duas, quatro, oito, 12 e 16 semanas após cada deposição de fezes nos canteiros experimentais. A altura da forragem foi medida em cada uma das subdivisões imediatamente antes das colheitas. A forragem foi cortada com uma tesoura de poda, rente ao solo, de uma área delimitada com o auxílio de um círculo de 10 cm de raio. As fezes foram recolhidas manualmente dos canteiros. A recuperação de L3 das amostras fecais foi maior quando as fezes foram depositadas em meio ao capim alto (com 30 cm - P<0,05). Porém, a recuperação de L3 nas forragens foi similar em ambos os cortes. Em relação à concentração de L3, o corte baixo propiciou maior quantidade de L3 por quilo de matéria seca (P<0,05). As maiores recuperações de L3, nas fezes e nas forragens, ocorreram quando as fezes foram depositadas no outono e na primavera. Dentre as espécies forrageiras, o capim aruana foi o que no geral apresentou maiores concentrações de larvas infectantes de T. colubriformis.
The purpose of the experiment was to evaluate infective Trichostrongylus colubriformis larvae (L3) survival in three forage species. Experimental modules formed by six 32.4-m2 plot, established with the following forage grass species, were used in the study: Australian Brachiaria decumbens cv., Cynodon dactilon cv. Coast-cross, and Panicum maximum cv. Aruana, totaling two plots for each species. Each plot was divided into 36 30 x 30 cm parts in order to allow six replicates per species and per height in each week of material collection. Larval survival was evaluated in the four seasons of the year under the effect of two forage paring heights (low, 5 cm, and high, 30 cm). The paring was carried out immediately before the feces were deposited. Four feces deposits were made, one in each season of the year. Feces and forage collection was performed one, two, four, eight, 12 and 16 weeks after each feces deposition in the experimental plots. Forage grass height was measured in each subdivision immediately before the collections. The forage was cut using pairing scissors, close to the soil, from an area delimited with a circle with a 10-cm radius. The feces were collected manually from the plots. L3 recovery rates from fecal samples were bigger when the feces were deposited in high grass (measuring 30 cm - P<0,05). However, L3 recovery in the forages was similar for both cuts. So far as the L3 concentration is concerned, the low cut resulted in a bigger number of L3 per kilogram of dry matter (P<0,05). The higher L3 recovery in the feces and in the forage grass occurred when the feces were deposited in the autumn and in the spring. Among the forage species, the aruana grass was the one that, in general, harbored the biggest concentrations of infecting T. colubriformis larvae.

Mestrado em Biologia Marinha
Os sistemas de transição costeira, como estuários e lagunas costeiras, estão entre os ecossistemas aquáticos mais produtivos e valiosos. Com uma grande variedade de habitats que desempenham funções vitais para as espécies que os habitam, tendo, consequentemente, uma enorme importância no funcionamento ecológico desses sistemas. A Ria de Aveiro é a maior laguna costeira de Portugal com 4 canais principais radiando da embocadura. O objetivo deste trabalho foi o estudo de uma das espécies mais características da Ria de Aveiro - o caranguejo verde Carcinus maenas. Os caranguejos inter-litorais têm uma intensa ligação com os processos dos ecossistemas estuarinos, sendo considerados uma key-stone specie na Ria de Aveiro. Um estudo global dos padrões ecológicos desta espécie (uso do habitat, distribuição espacial, estado da sua condição, comportamento gregário e mecanismos de migração de maré) pode contribuir para uma melhor compreensão do seu relacionamento e interação com o ecossistema de que faz parte, fornecendo também informação sobre o estado ecológico da região. Para tal, utilizaram-se nassas como método de amostragem e a colheita de amostras foi realizada mensalmente durante os primeiros 6 meses de um ano. A amostragem foi realizada em 5 tipos de habitat (Sublitoral, Areia, Misto, Zostera e Sapal) em 5 locais diferentes ao longo da laguna. Para estudar a migração de maré desta espécie utilizamos uma câmara de vídeo com a qual gravamos a migração de enchente durante os períodos do dia e da noite num habitat arenoso localizado no sub-estuário de Mira, na Ria de Aveiro. Verificamos que a população de fémeas e machos de caranguejos da Ria de Aveiro procura mais ativamente por alimento em períodos diferentes do ano. Descobrimos que o local e sua proximidade com a entrada da laguna parecem ser fatores importantes para a compreensão das diferentes distribuições espaciais de cada sexo pela Ria. Verificamos que o caranguejo verde apresenta diferenças espaciais e temporais no uso do habitat na Ria de Aveiro. Ao estudar a alometria da população, verificamos que ambos os sexos apresentavam tendências semelhantes de condição ao longo dos meses, com níveis mais baixos durante Março e níveis maiores em Junho, último mês amostrado. Os nossos resultados também sugiram que caranguejos adultos podem formar agregações com outros com tamanhos semelhantes (SD entre 7 mm para fémeas e 8 a 12 mm para machos). Verificamos a presença de grupos de 35 a 45 indivíduos adultos com características semelhantes de tamanho para cada sexo, especialmente evidente nas fémeas. Descobrimos que as migrações de maré durante o dia, cerca de 90 a 120 minutos após a maré baixa, em comparação com a noite, parecem ser realizadas num período mais tardio. A maioria dos caranguejos possuíam uma largura de carapaça de 20-50 mm; nenhum menor que 10 mm foi observado a executar a migração. Constatamos também que o comportamento migratório nessa espécie não parece ser segregado temporalmente por tamanho.
Coastal transition systems, such as estuaries and coastal lagoons, are among the most productive and valuable aquatic ecosystems. They have a great variety of habitats which perform vital functions for the species that inhabit them and that have, consequently, an overall ecologic importance in those systems. Ria de Aveiro is the largest coastal lagoon in Portugal with 4 main channels radiating from a common inlet. The aim of this paper was the study of one of the most conspicuous species present in Ria de Aveiro - the green crab Carcinus maenas. Intertidal crabs have extensive linkage to estuarine ecosystems processes being considered keystone species. An overall understanding of this species ecologic patterns (habitat use, spatial distribution, monthly condition, gregarious behavior and tidal migration mechanisms) may contribute to a better understanding of its interaction with the ecosystem, and, also, increase the comprehension of the ecological status of this lagoon. In order to do so, we used baited hoop nets’ in a monthly sampling programme that encompassed the first 6-month period of a year. The sampling was conducted in 5 different types of habitat (Subtidal, Sand, Mixed, Zostera and Marsh) in 5 different sites along the lagoon. To study the tidal migration of this species, we used an underwater video camera to film the flood migration during the day and night time in a sandy habitat located in Mira’s sub-estuary in Ria de Aveiro. From our study, we found that the female and male population of crabs in Ria de Aveiro search more actively for food during different periods of the year for every site. We found that site and its proximity to the lagoon’s mouth appear to be important factors when comparing sex segregation data. The green crab was found to presents spatial and temporal differences in the use of habitat in Ria de Aveiro. While studying the allometry of the population, we found that both sexes presented similar trends of condition through the months, with lower levels during March and higher levels in June, the last month sampled. Our findings also suggested that adult crabs may form aggregations with others with similar sizes (SD between 7 mm for females and 8 to 12 mm for males) We verified the presence of groups of 35 to 45 adult individuals with similar characteristics of size for each sex, especially evident in females. We found that tidal migrations were performed later in time during the day, around 90 to 120 minutes from low tide, than during night. Most crabs migrating were of 20-50 mm carapace width; none smaller than 10 mm was observed. We also found that the migratory behavior in this species seemed not to be segregated by size.

Sexual Segregation (SS) is a phenomenon that occurs across a wide range of animal species, and that had been broadly categorized in spatial/habitat segregation and social segregation. SS of a given species is often related quantitatively to its Sexual Size Dimorphism (SSD), which frequently drives to sexual differences that can work as a mechanism to avoid competition between individuals of opposite sex. SS has been widely studied among terrestrial birds. The few existing studies on SS involving pelagic seabirds have focused on the breeding period, and the extent of SS in relation to environmental conditions and fisheries and its persistence during the non-breeding period remains poorly understood in this taxa. In this thesis, we aimed to understand the causes and consequences of SS in spatio-temporal distribution (inferred through geolocation and GPS-tracking data), migratory phenology (inferred through light-level data from geolocators), behaviour (inferred through immersion data from geolocators) and feeding ecology (inferred through Stable Isotope Analysis (SIA)) of three closely-related shearwaters: Scopoli’s, Cory’s and Cape Verde shearwaters (Calonectris diomedea, C. borealis, and C. edwardsii, respectively). To assess and understand potential sex differences within or between breeding (for Scopoli’s shearwater) and non-breeding periods (for the three Calonectris shearwaters), we adopted a multidisciplinary approach combining geolocation, immersion data, GPS-tracking, spatial modelling and SIA. Our findings pointed out that during the breeding period, females of Scopoli’s shearwater seem to be outcompeted by males and forced to increase their foraging effort, especially under unfavourable conditions. This result suggests unfavourable conditions induced an inter-sexual competition for limiting resources, and males forced females to forage further from the colony. Furthermore, males interacted with fishing vessels to a greater extent, profiting from discards more than females. Otherwise, during the non-breeding period, both sexes of the three Calonectris shearwaters shared the same non-breeding areas, suggesting competitive exclusion does not promote spatial segregation throughout the annual cycle. Sexual differences in the migratory phenology were subtle for the three species, with males consistently returning earlier to breeding colonies, and male Cory’s shearwaters remaining resident in a larger proportion than females, likely due to sex-specific reproductive roles at early stages of the breeding period. For both breeding and non-breeding periods, males consistently feed on higher trophic levels (inferred from higher δ15N) than females, suggesting that sexual differences in diet may persist year-round. For the breeding period, we found an increase of δ15N values correlated with fishing vessel attendance, indicating that sexual differences observed may mostly emerge from differential fishing vessel attendance and consumption of fishery discards between males and females. However, the influence of SSD in bill size in determining differences in diet remains unclear. Overall, we found consistent differences in foraging movements, migratory phenology, and resource use between sexes, indicating a robust SS during breeding and non-breeding periods in shearwater species. Furthermore, our results indicated that SS in foraging strategies of Scopoli’s shearwater may lead to unbalanced exposure of males and females to bycatch in the North-Western Mediterranean, which could reduce effective population size and compromise the population viability of the species. This thesis increase our knowledge about SS in Calonectris species, and show that species with slight SSD also present well-marked SS and that intrinsic and extrinsic factors can promote inter-sexual differences throughout the annual cycle. Furthermore, we highlight that SS in distribution and foraging behaviour of Scopoli’s shearwater, and probably in other seabird species, should be taken into consideration when implementing specific conservation plans in the marine environment.
La segregación sexual (SS) es un fenómeno habitual en animales, como consecuencia de diferencias entre sexos en la distribución espacio-temporal, el comportamiento o la ecología trófica. En aves marinas, el estudio de la SS se ha centrado principalmente en el período reproductivo. En cambio, su alcance e implicaciones en relación a las condiciones ambientales, así como su ocurrencia fuera del período reproductivo, han sido menos estudiadas. Nuestro objetivo fue comprender las causas y consecuencias de la SS en la distribución, fenología migratoria, comportamiento y ecología trófica de tres especies emparentadas: la pardela cenicienta mediterránea, cenicienta atlántica y de Cabo Verde (Calonectris diomedea, C. borealis y C. edwardsii, respectivamente). Para ello evaluamos las diferencias sexuales en el periodo reproductivo (en la pardela cenicienta mediterránea) y de invernada, y discutimos si dichas diferencias se extienden a lo largo del ciclo anual. Para el periodo reproductivo, nuestros resultados indicaron que las hembras de pardela cenicienta mediterránea son menos competitivas que los machos, viéndose obligadas a incrementar el esfuerzo de búsqueda de alimento, especialmente ante condiciones ambientales desfavorables. Además, los machos fueron más proclives a interaccionar con barcos pesqueros, haciendo mayor uso de descartes, pero exponiéndose a un mayor riesgo de captura accidental, lo que podría comprometer el tamaño efectivo de la población y su viabilidad en el Mediterráneo noroccidental. Fuera del periodo reproductivo, ambos sexos compartieron las zonas de invernada en las tres especies, indicando que la exclusión competitiva no causa, al menos a escala espacial, SS a lo largo del año. Ambos sexos se alimentaron en diferentes niveles tróficos, sugiriendo que la segregación trófica persiste a lo largo del año. Encontramos sutiles diferencias en el calendario migratorio, siendo los machos los primeros en retornar a las colonias, y un mayor porcentaje de machos que de hembras de la pardela cenicienta atlántica no migró, probablemente como estrategia ventajosa de cara a las etapas iniciales del periodo reproductivo. En general, encontramos evidencias de SS en los movimientos de búsqueda de alimento, fenología migratoria y ecología trófica, tanto durante el período reproductivo como en el período de invernada en las tres especies de pardela.

Two species of swan are regularly found in Utah, tundra swans (Cygnus columbianus) and trumpeter swans (Cygnus buccinator). Tundra swans migrate through Utah. During the fall migration period they are hunted in the state under guidelines established by the United States Fish and Wildlife Service (USFWS). Trumpeter swans are occasional visitors to Utah during the same migration period. Because trumpeter swans are difficult to distinguish from tundra swans in flight, they 11 are at risk of being harvested during the swan hunt. In my thesis, I examine the factors that may influence trumpeter swan vulnerability to harvest. Specifically, I evaluated height and velocity of foraging flights for both species of swans and identified characteristics of Utah swan hunters. This information could assist the Utah Division of Wildlife Resources in developing an educational program to reduce trumpeter swan vulnerability. I applied flight dynamics theory to 86 trumpeter and 178 tundra swan measurements. Both speed and height of short-range foraging flights were used to predict trumpeter and tundra swan vulnerability. The theory predicted that trumpeter swans fly slower and lower than tundra swans, and thus may be more vulnerable to harvest. The predicted flight height of tundra swans was compared to observations of tundra swans made at the USFWS Bear River Migratory Bird Refuge. Average body area of the two species of swans was compared. Trumpeter swans had, on average, a 30% larger body area. Combining the lower predicted flight and larger body size, trumpeter swans may be up to 26% more vulnerable on a 3.8-km flight and 15% more vulnerable on a 10-km flight than tundra swans on the same flight path. In addition to current regulations, the Utah Division of Wildlife Resources is interested in implementing a swan hunter education course to further reduce the likelihood of a trumpeter swan being harvested during the swan hunt. I surveyed a representative sample of Utah swan hunters to determine if they would participate in the course and attitudes about current regulations, and to identify specific topics that should be emphasized in the course. My survey suggested that Utah swan hunters would be receptive to a swan hunter education course. Based on the responses, any swan hunter education course should emphasize identification of trumpeter and tundra swans, distance estimation, and regulations regarding the swan hunt.

Wildlife crossings are present as a part of infrastructure systems since the 1950’s. Their development through years has proven that they are an integral part when considering building highways all over the world. This paper is aimed to bring closer to a broader public the potential of wildlife crossings while also highlighting their importance. What is more an exemplary overpass over the S11 motorway in Poland has been designed following given recommendations and studying errors on already existing ones. Wildlife crossings divide into three main categories: overpasses, underpasses, and crossings over the road. The latter gives the worst results as to mortality rate which indicates the necessity to upgrade crossings over the road to ones minimalizing possibility of accidents. What is more, a social campaign should be started to explain briefly but firmly why do we even need animal crossings as there are many misconceptions regarding this subject. New visions and ideas focus mainly on integrity and aesthetics, as construction is already developed on a high note. Engineers should work closely with ecologists to ensure proper migration patterns and provide a continuation to migration corridors.

Migration timing is a conserved life-history trait. To address the hypothesis that reproductive hormones are principal determinants of migration timing, I physiologically biopsied over 1000 sockeye salmon and monitored their subsequent behaviour with acoustic and radio telemetry as they migrated from the Pacific Ocean toward and into the Fraser River, and then onward to distant spawning areas. Links between physiology, behaviour, and survival were examined. Circulating testosterone was found to be positively correlated with the rates of river entry in Late-run females but not in males, despite having concentrations that were equal if not higher than those of females. The notion of protandrous migration, in which males synchronize their activities to the reproductive and migratory schedules of females, was postulated as the basis for this difference. Once in river however, successful males and females were those that (1) took longest to enter the river, and (2) had high somatic energy, low testosterone, and low gill Na+,K+-ATPase activities. An experimental test of the effect of reproductive hormones on the regulation of migration timing proved inconclusive. Relative to controls, GnRH and (or) testosterone treatment did not influence rates of ocean travel by males. Unfortunately, no females were examined. Nevertheless, significant, positive correlations between initial testosterone and travel times were found irrespective of hormonal treatment, which was unexpected but consistent with the previous studies. In an experimental simulation of an ‘early’ migration, normally timed Late-run sockeye exposed to typical 10 ºC river temperatures and then released to complete migration were 68% successful. In contrast, salmon held at 18 °C and released were half as successful. The expression of a kidney parasite was near maximal in the 18 °C fish and undetectable in the 10 °C fish. Only gill Na+,K+-ATPase activity differed between groups, with a drop in the 18 °C fish. Though no clear stress, reproductive, or energetic differences were observed between groups, the ultimate effect of high temperature treatment was high disease expression, slowed migration speeds, and high migration mortality. Changes in reproductive schedules, due to changes in latitudinal ocean distributions, are discussed as potential causes of early migration by Late-run sockeye.

Orientador: Alessandro Francisco Talamine do Amarante
Banca: Solange Maria Gennari
Banca: Cledson Augusto Garcia
Banca: Reinaldo José da Silva
Banca: Patrizia Ana Bricarello
Resumo: O experimento teve como objetivo avaliar a sobrevivência de larvas infectantes (L3) de Trichostrongylus colubriformis em três espécies forrageiras. Para tal, foram utilizados módulos experimentais constituídos por seis canteiros de 32,4 m2 cada, estabelecidos com as seguintes gramíneas forrageiras: Brachiaria decumbens cv. Australiana, Cynodon dactilon cv. Coast-cross e Panicum maximum cv. Aruana, perfazendo dois canteiros por espécie. Cada canteiro foi dividido em 36 parcelas, de 30 x 30 cm, de forma a permitir seis repetições por espécie e por altura em cada semana de colheita de material. A sobrevivência larval foi avaliada nas quatro estações do ano, sob o efeito de duas alturas de poda das forragens (baixa, 5 cm e alta, 30 cm). A poda foi realizada imediatamente antes da deposição das fezes. Ocorreram quatro deposições de fezes, uma a cada estação do ano. A colheita das fezes e da forragem foi realizada uma, duas, quatro, oito, 12 e 16 semanas após cada deposição de fezes nos canteiros experimentais. A altura da forragem foi medida em cada uma das subdivisões imediatamente antes das colheitas. A forragem foi cortada com uma tesoura de poda, rente ao solo, de uma área delimitada com o auxílio de um círculo de 10 cm de raio. As fezes foram recolhidas manualmente dos canteiros. A recuperação de L3 das amostras fecais foi maior quando as fezes foram depositadas em meio ao capim alto (com 30 cm - P<0,05). Porém, a recuperação de L3 nas forragens foi similar em ambos os cortes. Em relação à concentração de L3, o corte baixo propiciou maior quantidade de L3 por quilo de matéria seca (P<0,05). As maiores recuperações de L3, nas fezes e nas forragens, ocorreram quando as fezes foram depositadas no outono e na primavera. Dentre as espécies forrageiras, o capim aruana foi o que no geral apresentou maiores concentrações de larvas infectantes de T. colubriformis.
Abstract: The purpose of the experiment was to evaluate infective Trichostrongylus colubriformis larvae (L3) survival in three forage species. Experimental modules formed by six 32.4-m2 plot, established with the following forage grass species, were used in the study: Australian Brachiaria decumbens cv., Cynodon dactilon cv. Coast-cross, and Panicum maximum cv. Aruana, totaling two plots for each species. Each plot was divided into 36 30 x 30 cm parts in order to allow six replicates per species and per height in each week of material collection. Larval survival was evaluated in the four seasons of the year under the effect of two forage paring heights (low, 5 cm, and high, 30 cm). The paring was carried out immediately before the feces were deposited. Four feces deposits were made, one in each season of the year. Feces and forage collection was performed one, two, four, eight, 12 and 16 weeks after each feces deposition in the experimental plots. Forage grass height was measured in each subdivision immediately before the collections. The forage was cut using pairing scissors, close to the soil, from an area delimited with a circle with a 10-cm radius. The feces were collected manually from the plots. L3 recovery rates from fecal samples were bigger when the feces were deposited in high grass (measuring 30 cm - P<0,05). However, L3 recovery in the forages was similar for both cuts. So far as the L3 concentration is concerned, the low cut resulted in a bigger number of L3 per kilogram of dry matter (P<0,05). The higher L3 recovery in the feces and in the forage grass occurred when the feces were deposited in the autumn and in the spring. Among the forage species, the aruana grass was the one that, in general, harbored the biggest concentrations of infecting T. colubriformis larvae.
Doutor

In recent years, human decision-making has led to significant landscape impacts in the western United States. Specifically, migratory wildlife populations have increasingly been impacted by rural urban development and energy resource development. This research presents the application of agent-based modeling to explore how such impacts influence the characteristics of migratory animal movement, focusing on mule deer (Odocoileus hemionus) in Western Wyoming. This study utilizes complex adaptive systems and agent-based modeling frameworks to increase understanding of migratory patterns in a changing landscape and explores thresholds of interference to migration patterns due to increased habitat degradation and fragmentation. The agent-based model utilizes GPS-collar data to examine how individual processes lead to population-level patterns of movement and adaptation. The assessment incorporates elements from both human and natural systems to explore potential future scenarios for human development in the natural landscape and incorporates adaptive behaviors, as well as animal-movement ecology, in changing landscapes.

One of the most fascinating aspects of birds is their capability of migrate from one area to another throughout the year. Unravelling the patterns and processes involved in the evolution of migration is paramount to understand the current biogeography, ecology and evolution of migratory birds. On this basis, the main aim of the present thesis was to extend the knowledge of the mechanisms involved in the evolution of bird migration. To achieve that two main sections are presented in this thesis. In the first one, the aims were to disentangle the patterns of evolution of migratory behaviour and the identifying the main factors that could play an important role in it, using Sylvia warblers as case of study. In the second section, we explored the climatic niche and the potential distribution of breeding and wintering ranges in the last glacial maximum (LGM) of trans-Saharan long migratory species, in order to unravel the changes in migratory behaviour. We explored the evolution of migration in Sylvia warblers as both a discrete and continuous character using ancestral state reconstruction methods. We recovered the basal node as migratory in most analyses, suggesting seven independent losses of migratory behaviour in Sylvia warblers. Both analyses performed with migration as discrete or continuous character recovered different probabilities of sedentariness or migratoriness in some conflicting nodes depending of the ASR elements used. This forced as to consider controversial hypotheses of evolution of migration in some clades that could evolved from migratory to sedentary in a very short period of time or going through a partial migratory status instead. We used phylogenetic comparative methods to assess whether the evolutionary patterns of migratory distances are correlated with several biometric, climatic and productivity variables in a phylogenetic context, using Sylvia warblers as a case study. Our results recover net primary productivity (NPP) in the breeding range and during the breeding season as the variable with stronger positive correlation with migratory distances. Several climatic variables show a correlation with the evolution of migration and among morphological variables, migratory lineages tend to have longer wings than sedentary ones. It is not possible to disentangle if NPP was a main driver in the evolution of bird migratory behaviour or a consequence of it, yet migration and NPP seem to be tightly related today and along their evolutionary history. Migratory birds occupy different geographic areas during breeding and wintering periods and are exposed to different factors. One of those factors is the climatic component of the niche. We tested if migratory birds display similar climatic conditions in both breeding and wintering areas, using 355 bird migratory species from Eurasian to Africa flyways. Our results show that there is not climatic niche overlap between both ranges. This suggests that the climatic niche of most Euro-African migratory species is larger than expected. Given these results, both breeding and wintering climatic data need to be considered when performing species distribution models, to incorporate the total width of the climatic niche. During the Plio-Pleistocene, glacial cycles have shaped Northern Hemisphere birds' distributions that could result in changes in their migratory behaviour. In this context, it has been suggested that long-distance North American migratory species could have lost their migratory condition during cold periods regaining it later in warmer periods. We tested this hypothesis in Eurasian-African extant migratory bird species. We modelled present and LGM distribution of 80 trans-Saharan bird migratory species and we revised the available fossil record. Our results show a southwards reduction of the breeding distributions during the LGM compared to the present and similar wintering areas in the present and Pleistocene, with the Saharan belt gap always present through time. These results and the Pleistocene fossils from Africa not support the hypothesis of a loss of migratory condition in these species.
Uno de los aspectos más fascinantes dentro de la ornitología es el estudio de la migración. Saber cuáles son los patrones y procesos implicados en la evolución de la migración, permite descubrir tanto componentes ecológicos, biogeográficos como evolutivos dentro las aves. Por ello, en esta tesis se pretende aumentar el conocimiento acerca de los mecanismos implicados en la evolución de la migración en algunas aves. Por un lado, se investigó cómo evolucionó la migración y qué factores pueden actuar como motores de su evolución en un contexto filogenético usando el género Sylvia como caso de estudio. Encontramos que los procesos de cambio en el comportamiento migratorio ocurrían siempre de migratorio a sedentario, siendo el antecesor del género también migratorio. Esto supone que probablemente el coste de pasar de migratorio a sedentario es menor que al revés. Además, evaluando si factores como el clima, la morfología o la productividad eran importantes en la evolución de la migración en el género Sylvia, encontramos que la productividad juega un papel muy importante. Esto supone que probablemente las especies comenzaron a migrar aprovechando los picos de productividad que surgen en latitudes medias durante la época de cría. Por otro lado, se investigó la evolución de la migración en un contexto biogeográfico y macrecológico utilizando especies migratorias Euro-Africanas. Primero se evaluó si las especies migratorias están sometidas a las mismas condiciones climáticas tanto en las zonas de cría como en invernada. Si fuera así, las especies migratorias podrían moverse guiándose o en busca de condiciones similares a lo largo de todo el año. Sin embargo, encontramos que no es así y por lo tanto las especies migratorias presentan un nicho climático mayor de lo esperado que es necesario tener en cuenta a la hora de hacer modelos de distribución. Considerando esto, realizamos modelos de distribución de especies transaharianas tanto en el presente como durante el último glacial máximo. En este caso queríamos descubrir si las especies seguían migrando cuando parte del Paleártico estaba cubierto de nieve, o si se hicieron sedentarias como se ha sugerido para especies migratorias norteamericanas. Nuestros resultados, junto con el registro fósil consultado, no apoyan que las especies dejaran de migrar, sino que probablemente redujeran sus distancias migratorias.

The purpose of this study is to examine lifestyle migration as a cultural and everyday practice, with the emphasis being on observing how lifestyle changes from urban to rural are described, practiced and made meaningful by people who have left major Swedish cities behind, in favour of a life on the Gotlandic countryside. The empirical material has been collected through ethnographical methods and is based on observations and qualitative interviews with 13 individuals who all reside on farms and practice animal husbandry. Focus has been placed on the practices, conceptions and other expressions which are related to the informants’ animals and their keeping. The theoretical starting point of this study is phenomenological, where anthropologist Tim Ingold’s ideas of what it means to dwell are central. Also, the term authenticity and the concept of lifestyle migration are important tools to examine the collected material. The result of the study demonstrates that the idea of the rural idyll, in other words, the preconception of the countryside as a calm and harmonious refuge far removed from the stressful life of major cities, plays a large part in the in-migrants lifestyle migration. The informants’ decisions to move to the countryside, as well as their everyday practices once settled in, are characterised by these romanticised notions. The study also shows that the informants’ lives, with animals and their keeping, presents a series of unexpected challenges and difficulties that are not present in the preconception of the rural idyll. In reality, the informants experience more stress and even higher workloads in their rural everyday, than they were exposed to living their previous urban lifestyle. The animals and their care, however, provide a series of positive experiences and the interactions with the animals are seen as authentic and meaningful. The everyday interchanges with the animals become an important part of the informants’ being and wellbeing on the countryside. They are therefore crucial to their lifestyle migration.

In this study, the factors influencing zooplankton community structure in Turkish shallow lakes were elucidated with four main approaches: (i) space-for-time substitution for shallow lakes using snap-shot sampling in 31 lakes along a latitudinal gradient
(ii) in-situ mesocosm experiments in eleven lakes along a latitudinal gradient using three sets of artificial plants systems
(iii)&lsquo
Habitat Choice&rsquo
laboratory experiments mimicking a &lsquo
shallow littoral&rsquo
zone with plants and a &lsquo
deeper pelagic&rsquo
zone with sediments testing the response of Daphnia magna to predation cues
and (iv) long-term monitoring data (1997-2011) from two interconnected lakes. Snap-shot and long-term monitoring showed that eutrophication has a strong influence on the zooplankton community via increased fish predation, nutrient loading and salinization. Here too the zooplankton community shifted towards a smaller sized profile, especially in lakes located at lower latitudes. Moreover, The laboratory and in-situ mesocosm experiments revealed that under predation risk Daphnia preferred to hide near sediment instead of using submerged plants as a refuge. Accordingly, in-situ mesocosm experiments revealed a predation pressure induced size structure shift towards small-medium sized zooplankton and calanoid copepods. The long-term monitored lakes experienced (i) drought-induced water level drop, leading to increased salinity and eutrophication, and consequent anoxic conditions and fish kill
as well as (ii) biomanipulation in the downstream. Both conditions resulted in major reduction in the top-down control of fish and ultimate predomination by large sized Daphnia spp. Nevertheless, the excessive exploitation of lakes and ongoing warming entail Turkish shallow lakes to become more eutrophic, making this study indicative for the Mediterranean region.

Thesis: Ph. D., Joint Program in Applied Ocean Science and Engineering (Massachusetts Institute of Technology, Department of Earth, Atmospheric, and Planetary Sciences; and the Woods Hole Oceanographic Institution), 2018.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 138-154).
Highly migratory marine fishes support valuable commercial fisheries worldwide. Yet, many target species have proven difficult to study due to long-distance migrations and regular deep diving. Despite the dominance of oceanographic features, such as fronts and eddies, in the open ocean, the biophysical interactions occurring at the oceanic (sub)mesoscale (< 100 km) remain poorly understood. This leads to a paucity of knowledge on oceanographic associations of pelagic fishes and hinders management efforts. With ever-improving oceanographic datasets and modeling outputs, we can leverage these tools both to derive better estimates of animal movements and to quantify fish-environment interactions. In this thesis, I developed analytical tools to characterize the biophysical interactions influencing animal behavior and species' ecology in the open ocean. A novel, observation-based likelihood framework was combined with a Bayesian state-space model to improve geolocation estimates for archival-tagged fishes using oceanographic profile data. Using this approach, I constructed track estimates for a large basking shark tag dataset using a high-resolution oceanographic model and discovered a wide range of movement strategies. I also applied this modeling approach to track archival-tagged swordfish, which revealed affinity for thermal front and eddy habitats throughout the North Atlantic that was further corroborated by synthesizing these results with a fisheries-dependent conventional tag dataset. An additive modeling approach applied to longline catch-per-unit effort data further highlighted the biophysical interactions that characterize variability in swordfish catch. In the final chapter, I designed a synergistic analysis of high-resolution, 3D shark movements and satellite observations to quantify the influence of mesoscale oceanography on blue shark movements and behavior. This work demonstrated the importance of eddies in structuring the pelagic ocean by influencing the movements of an apex predator and governing the connectivity between deep scattering layer communities and deep-diving, epipelagic predators. Together, these studies demonstrate the breadth and depth of information that can be garnered through the integration of traditional animal tagging and oceanographic research with cutting-edge analytical approaches and high-resolution oceanographic model and remote sensing datasets, the product of which provides a transformative view of the biophysical interactions occurring in and governing the structure of the pelagic ocean.
by Camrin Donald Braun.
Ph. D.

Movement is a widespread characteristic in the animal kingdom —occurring at many spatiotemporal scales— with consequences at an individual, population, species, and even ecosystem level. It is a very diverse character, with many different drivers that stem from the way in which individuals interact with their environment. Of these, one of the most important is the distribution of resources, particularly for migratory and foraging movements. In migration, the search for an optimal environment involves movement at large spatiotemporal scales, following seasonal changes in resource distribution. In foraging movements, the search for resources happens at small spatiotemporal scales, and involves different strategies to optimise the search and capture of food, including the ability to obtain foraging cues from conspecifics. In seabirds, movement —at large and local scales— has deep repercussions in their life-history traits, evolutionary history, morphology, physiology and behaviour, which makes them a very valuable study group to understand the role, the causes and consequences of migratory and foraging movements in the ecology of marine top- predators. The study of migratory and foraging movements has been revolutionised by the development of smaller, cheaper and better tracking devices, promoting multi-colony, population and even species approaches to the study of animal movement, but which also come with a set of methodological challenges that have to be addressed in order to make unbiased inferences of space and habitat use at population or species level from individual movement data. In this thesis, we develop methods to test the possible biases introduced by the use of individual tracking data to infer distribution at a population or species level. we then apply these tools to a multi-colony dataset of non-breeding locations of Cory’s (Calonectris borealis), Scopoli’s (C. diomedea) and Cape Verde (C. edwardsii) shearwaters, to study their migratory connectivity and non-breeding habitat segregation at the colony, population and species level. Lastly, we apply state-of-the-art spatial models to study foraging distributions of three neighbouring colonies of Cory’s shearwaters, detect the segregation among them and unravel the environmental and behavioural drivers of this segregation. I developed several functions in the R environment aimed at the detection of the effects of individual site fidelity and temporal variability in the inference of spatial use at a colony or population level, and to calculate the degree in which the movements of a single population can be representative of those of the entire species. These tools are applicable to individual movement data regardless of the species or tracking device. we also used these tools to demonstrate the spatial and ecological segregation between the non-breeding distributions of three taxa of Calonectris shearwaters studied, as well as detecting a stronger degree of migratory connectivity at a population than at a colony level, indicating that individuals of different colonies within a population mix in the non-breeding areas, but birds from different populations do not, which has important implications for their population dynamics and for their conservation and management. Lastly, we demonstrated segregation among the foraging distributions of three neighbouring colonies of Cory’s shearwaters, both in the waters surrounding the colony and in distant, foraging grounds, finding evidences of both environmental and behavioural drivers behind this segregation, and suggesting a mechanism through which transfer of information between individuals can be shaping the distributions of foraging seabirds. The results of this thesis provide relevant tools for the field of movement ecology, as they can be used for analysing movements of mobile species, regardless of species, tracking device or spatiotemporal scale. In addition, they are relevant for the field of seabird ecology as they provide insights into the causes of space and habitat use in long-ranging pelagic seabirds.
El moviment és una característica omnipresent en el regne animal, a les més diverses escales espacio-temporals i amb conseqüències a diferents nivells (individual,. poblacional, específic i fins i tot ecosistèmic). La força impulsora del moviment més predominant i generalitzada és distribució dels recursos en el medi, important tant a gran escala (moviments migratoris) com en els moviments diaris de recerca d’aliment a escala petita. En les aus marines en particular, el moviment té repercussions profundes en les seves característiques morfològiques i de comportament, en la seva història de vida, i la seva història evolutiva. El desenvolupament de dispositius de seguiment més petits, barats i precisos ha promocionat la proliferació d’estudis del moviment animal des d’un punt de vista multi- colònia, de població i fins i tot d’espècie. En aquesta tesi, desenvolupo diferents funcions per testar els biaixos introduïts en l’estudi del moviment, a través de dades de seguiment individual, a nivell de població o espècie. Posteriorment, utilitzo aquestes eines per a analitzar la connectivitat migratòria i la segregació dels hàbitats d’hivernada, des d’un punt de vista multi-colònia, de les baldrigues cendroses de l’Atlàntic (Calonectris borealis), del Mediterrani (C. diomedea), i de Cap Verd (C. edwardsii). Per últim, aplico un mètode innovador de modelatge espacial per a estudiar les distribucions d’alimentació de baldrigues cendroses de l’Atlàntic criant en tres colònies veïnes, per detectar-ne la segregació i descobrir-ne les causes, tant ambientals com comportamentals, incloent com els diferents mecanismes de transferència d’informació entre individus poden afectar a aquestes distribucions. Els resultats d’aquesta tesi tenen rellevància per a la ecologia del moviment en general, ja que són aplicables a dades de moviment individual de qualsevol espècie, independentment de l’aparell de seguiment utilitzat, i en el camp de l’ecologia de les aus marines, ja que proporciona nous coneixements sobre els diferents factors afectant la distribució i l’ús de l’espai, tant durant la cria com durant la hivernada, en aus pelàgiques.

Le déplacement animal joue un rôle déterminant dans la structuration spatiale et la dynamique des populations biologiques, en particulier des espèces fortement mobiles. L’espace et l’environnement font ainsi partie intégrante du cycle de vie des tortues marines. Ce travail de thèse propose de caractériser l’écologie spatiale des tortues marines, du stade juvénile au stade adulte, dans le Sud-ouest de l’océan Indien, principalement par l’usage de deux méthodes : la télémétrie satellitaire et la modélisation individu-centrée. Il montre en premier lieu que la phénologie de la reproduction de la tortue verte à travers la région est principalement liée à la température de surface de la mer au voisinage des sites de reproduction. Sont ensuite étudiés les patrons de dérive des nouveau-nés générés par les courants océaniques qui impacteraient inégalement leurs traits d’histoire de vie selon l’emplacement du site de naissance. Concernant le stade immature, les résultats suggèrent un cycle de développement trans-équatorial pour la tortue caouanne dans l’océan Indien. Pour le stade adulte, cette étude caractérise les couloirs et la connectivité migratoires de la tortue verte dans la région. Enfin, l’intégration de ces résultats permet de comprendre la structuration des patrons migratoires régionaux et leur influence sur la dynamique des populations. L’ensemble des connaissances acquises fournit un support concret d’aide à la décision pour la mise en place de plans de gestion et de conservation des tortues marines dans le Sud-ouest de l’océan Indien. Cela souligne l’importance d’une approche à grande échelle pour la protection d’un patrimoine biologique partagé par plusieurs nations
Animal movement is crucial to the ecology of spatially structured population, particularly for highly mobile species. Marine turtles’ life cycle is indeed closely related to spatial and environmental factors. This work analyses the spatial ecology of marine turtles, from early juvenile to adult stages, in the Southwest Indian Ocean, primarily through the use of two methods: satellite tracking and individual-based modeling. Firstly, this analysis argues that green turtle’s reproductive phenology across the region is mainly related to the sea surface temperature in the vicinity of the nesting site. Then, it shows how drifting trajectories of hatchlings in oceanic currents unevenly influence their life history traits depending on the position of the natal site. By tracking late juvenile stage, this work also suggests a trans-equatorial developmental cycle for loggerhead turtle in the Indian Ocean. At adult stage, it describes migratory corridors and connectivity for green turtle across the region. Finally, an integrative approach considering all these results allows for an understanding of the regional migratory patterns and their influence on population dynamics. The results of this work provide a practical policy decision tool for management and conservation of marine turtles in the Southwest Indian Ocean and highlight the need for a large-scale approach in the protection of biological resources and heritage shared by multiple nations

The overwintering ranges of North American bird populations are shifting and the winter ranges of south Florida’s landbirds remain understudied. Expert-drawn range maps used for scientific studies and environmental public policy could therefore be depicting inaccurate ranges for many migratory birds. This study used citizen science data from eBird (2001–2017) to evaluate patterns in overwintering avian species richness and identify discrepanciesin expert-drawn species range maps for overwintering passerines in south Florida. Most of Florida’s overwintering bird species were sighted in south Florida. Of the species observed there between 2001 and 2017, 66% had range map discrepancies. Fifteen target species were examined in the present study and fourteen of them were sighted in south Florida throughout the winter. None of these were depicted on range maps as overwinterers. These results showed that current expert-drawn range maps likely misrepresent the current winter ranges of passerine species in south Florida.

Large marine vertebrate species can exhibit vast movements, both horizontally and vertically, which challenges our ability to observe their behaviours at extended time-scales. There is a growing need to understand the intra- and inter-annual movements of mobile marine species of conservation concern in order to develop effective management strategies. The basking shark (Cetorhinus maximus) is the world's second largest fish species, however, a comprehensive understanding of this species’ ecology, biology and spatial behaviour in the north-east Atlantic is currently lacking. This thesis seeks to investigate the movement ecology of basking sharks using a suite of technologies to integrate biologging, biotelemetry, remotely sensed data, and ecological modelling techniques. I use satellite telemetry data from basking sharks tracked in 2012, 2013 and 2014 to quantify movements in coastal waters off the west coast of Scotland within the Sea of the Hebrides proposed MPA. Sharks exhibited seasonal residency to the proposed MPA, with three long-term tracked basking sharks demonstrating inter-annual site fidelity, returning to the same coastal waters in the year following tag deployment (Chapter 2). I reveal that sharks tracked into winter months exhibit one of three migration strategies spanning nine geo-political zones and the High Seas, demonstrating the need for multi-national cooperation in the management of this species across its range (Chapter 3). I examine the vertical space-use of basking sharks to improve an understanding of the processes that influence movements in all dimensions. Basking sharks exhibit seasonality in depth-use, conduct deep dives to over 1000 m, and alter their depth-use behaviour in order to remain within thermal niche of between 8 and 16 oC (Chapter 4). Finally, I combine contemporaneous data recorded by deployed satellite tags with remotely sensed environmental data to employ novel ecological modelling techniques to predict suitable habitat for basking sharks throughout the Atlantic Ocean (Chapter 5).

[ES] Resumen Como pez de gran valor económico, procedente de una de las líneas de teleósteos más antiguas, con un ciclo de vida misterioso, un potencial de acuicultura excepcional, y con importancia cultural y actividades de pesca en casi todos los países de Europa, la anguila europea posee un enorme valor socioeconómico. Este valor se suma a la desgraciada situación actual en peligro crítico de población natural de anguilas europeas. Como el ciclo de vida de la anguila aún no se ha conseguido cerrar en cautiverio, si la especie se extingue en la naturaleza, no seremos capaces de recuperarla. El cierre del ciclo de vida de la anguila europea ha sido, por lo tanto, el objetivo final de varios estudios. Sin embargo, a pesar de una investigación científica sustancial, desde la década de 1930, varios aspectos de la maduración de la anguila, como el mecanismo que bloquea la maduración de la anguila en la etapa prepúber en cautiverio, aún no se conocen bien. Por lo tanto, es necesario ampliar nuestro conocimiento sobre la reproducción de la anguila para inducir mejores hipótesis y lograr un progreso sustancial. Para profundizar en este campo, esta tesis se realizó con el objetivo específico de desarrollar métodos innovadores para la inducción de la maduración de la anguila y aumentar el conjunto de conocimientos sobre los procesos europeos de maduración de la anguila. Los procedimientos hormonales utilizados actualmente para la maduración sexual de la anguila artificial probablemente no induzcan el proceso natural de maduración. Por lo tanto, esta tesis ha evaluado el potencial de las hormonas recombinantes específicas de la anguila para inducir un proceso de maduración más natural. Este estudio específico mostró que la espermatogénesis completa y la espermiación se pueden inducir con gonadotropinas específicas de anguila recombinante; sin embargo, la calidad del gameto resultante es aún inferior a los resultados de los protocolos establecidos. Sin embargo, la utilización de hormonas recombinantes tiene un gran potencial para futuras implementaciones. Además, el experimento de gonadotropina recombinante ha generado nuevos detalles sobre el efecto de las gonadotropinas homólogas en el eje BPG de las anguilas europeas. Trabajos previos han llevado a la hipótesis de que un tratamiento térmico adecuado puede reducir o reemplazar parcialmente los tratamientos hormonales estándar para la maduración sexual de la anguila europea, o puede mejorar la calidad y / o cantidad de gametos. En esta tesis, se probó el efecto de varios regímenes térmicos en el eje BPG de machos de anguila europeos prepúberes, sin administración de hormonas. Los resultados muestran claramente que un tratamiento de agua de mar fría durante 2 semanas (10 ° C) afecta el eje BPG de los machos de anguila europeas. Los resultados específicos incluyeron un aumento en la sincronización de espermatogonias, niveles elevados de testosterona y 11-ketotestosterona en plasma, agrupamiento de muestras de transcriptomas del eje BPG del grupo tratado con agua de mar fría y posiblemente niveles aumentados de la proteína subunidad ß de la hormona luteinizante de la hipófisis. Los genes transcritos diferencialmente incluyeron varios genes, procesos y vías interesantes, que parecen estar involucrados en la maduración "natural" temprana de la anguila y que pueden ser biomarcadores adecuados para las distintas etapas de este proceso. Para un análisis adecuado de los datos transcriptómicos, se creó un transcriptoma de anguila europea de novo. Se demostró que este transcriptoma de novo posee una superior integridad al genoma de anguila europea disponible y, por lo tanto, es una herramienta útil para el análisis adicional de genes específicos. Un análisis de este transcriptoma reveló un gran número de pares de genes parálogos, que mostraron una baja divergencia entre secuencias sinónimas. Entre las hipótesis potenciales sobre e
[CAT] Com a espècie de renom culinari que pertany a un dels llinatges teleostis més antics, amb un cicle vital misteriós, un potencial d'aqüicultura excepcional, i una tradició pesquera a gairebé tots els països d'Europa, l'anguila europea posseeix un enorme valor socioeconòmic. No obstant això, aquest valor només fa que augmentar la preocupació de la seva població, que actualment es troba catalogada com "en perill crític d'extinció". Atès que el cicle de vida de les anguiles encara no ha estat tancat en captivitat, l'espècie no serà salvable en el cas que s'extingeixi en estat natural, per la qual cosa tancar el cicle de vida d'aquesta espècie ha estat l'objectiu final de diversos grups d'investigació durant els últims anys.. No obstant això, i malgrat la investigació científica de qualitat duta a terme des de la dècada de 1930, encara hi han diversos aspectes de la maduració de les anguiles -com el mecanisme que bloqueja la maduració sexual de l'anguila a l'etapa pre-puberal en captivitat- que son poc coneguts en l'actualitat. Per tal d'ampliar els coneixements sobre la reproducció de les anguiles i aconseguir un progrés substancial, aquesta tesi es va dur a terme amb l'objectiu específic de desenvolupar mètodes innovadors per a la inducció de la maduració de l'anguila europea, a més de afegir-hi el coneixement en els processos de maduració bàsics d'aquesta espècie. Els procediments hormonals utilitzats actualment per a la maduració artificial de l'anguila europea no acaben d'induir el procés de maduració natural tal i com probablement es dóna a la natura. Doncs, en primer lloc, aquesta tesi va avaluar el potencial d'hormones recombinants específiques d'anguila europea per induir un procés de maduració molt més natural. Aquest estudi específic va mostrar que mitjançant estes gonadotropines específiques d'anguila europea és possible induir l'espermatogènesi i l'espermiació completes. Tot i que els resultats van mostrar que la qualitat dels gamets va ser inferior als resultats que generen els protocols establerts fins ara amb un altre tipus d'hormones (generalment d'origen humà), la utilització d'hormones recombinants específiques es presenta amb un gran potencial per a la seva implementació futura en la inducció de la maduració sexual de l'anguila europea, ja que l'estudi va generar noves idees sobre l'efecte de les gonadotropines l'eix BPG de l'anguila europea. En segon lloc, i treballant amb la hipòtesi que un tractament tèrmic adequat pot reduir o substituir parcialment els tractaments hormonals estàndards per a la maduració sexual de l'anguila europea, en aquesta tesi es va provar l'efecte de diversos règims tèrmics (sense administració d'hormones) en l'eix BPG dels mascles europeus pre-puberals amb l'objectiu de millorar la qualitat i / o quantitat dels gamets. Els resultats mostraren clarament que un tractament d'aigua de mar de 2 setmanes a baixa temperatura (10 °C) va afectar l'eix BPG dels mascles europeus d'anguila. Resultats més específics van mostrar un augment de la sincronització de les espermatogonies, elevats nivells plasmàtics de testosterona i 11-ketotestosterona, una agrupació de mostres de transcriptoma de l'eix BPG del grup tractat amb aigua de mar freda i, possiblement, un augment dels nivells de la proteïna de la subunitat ß de la hormona luteinitzant de la hipofisi. Els gens transcrits diferencials van al·ludir a diversos gens, processos i vies interessants, que semblen estar implicats en la maduració inicial de l'anguila "natural" i podrien resultar biomarcadors adequats per a les etapes d'aquest procés. No obstant això, es necessiten estudis addicionals per avaluar el potencial dels biomarcadors d'aquests gens i, de manera complementària, comprovar si un pre-tractament d'aigua de mar freda pot millorar la resposta de les anguiles europees a un tractament hormonal artificial, com suggereixen els resultats. Finalment, amb l'objectiu
[EN] As an expensive fish from one of the most ancient teleost lineages, with a mysterious life cycle, exceptional aquaculture potential, and cultural associations and fishing activity in almost every country in Europe, the European eel possess huge socioeconomic value. This value only adds to the misfortune of the current critically endangered state of the wild European eel population. As the eel lifecycle has not yet been closed in captivity, the species will not be salvable if it went extinct in the wild. Closing the life-cycle of the European eel has thus been the ultimate objective of several studies. However, despite the substantial scientific investigation, since the 1930s, several aspects of eel maturation, such as the mechanism which blocks eel sexual maturation at the pre-pubertal stage in captivity, is still poorly understood. Therefore, it is necessary to broaden our knowledge of eel reproduction to induce better hypotheses and therethrough achieve substantial progress. In order to further this field, this thesis was conducted with the specific objective of developing innovative methods for induction of eel maturation and add to the pool of knowledge of European eel maturation processes. The hormonal procedures currently used for artificial eel sexual maturation are probably not inducing the natural maturation process. Therefore, this thesis has evaluated the potential of eel specific recombinant hormones to induce a more natural maturation process. This specific study showed that full spermatogenesis and spermiation can be induced with recombinant eel specific gonadotropins; however, the resulting gamete quality is still inferior to the results of established protocols. Nevertheless, the utilization of recombinant hormones holds a large potential for future implementation. Furthermore, the recombinant gonadotropin experiment has generated novel insights into the effect of homologous gonadotropins on the BPG axis of European eels. Previous work has led to the hypothesis that the right thermal environmental treatment may reduce or partially replace the standard hormonal treatments for sexual maturation of European eel, or may improve gamete quality and/or quantity. In this thesis, the effect of various thermal regimes was tested on the BPG axis of pre-pubertal European eel males, without administration of hormones. The results clearly show that a 2 week cold (10 °C) seawater treatment effects the BPG-axis of European eel males. Specific results included an increase in the synchronization of spermatogonial cells, elevated testosterone and 11-ketotestosterone plasma levels, clustering of BPG-axis transcriptome samples from the cold seawater treated group and possibly increased levels of pituitary luteinizing hormone ß-subunit protein. Differentially transcribed genes alluded to several interesting genes, processes, and pathways, which appears to be involved in early "natural" eel maturation and may prove to be suitable biomarkers for the stages of this process. In order for proper analysis of the transcriptomic data, a de novo European eel transcriptome was assembled. This de novo transcriptome was proven to have superior completeness to the available European eel genome and is thus a useful tool for further analysis of specific genes. An analysis of this transcriptome revealed a large number of paralog gene pairs, which showed low synonymous sequence divergence. Among the potential hypothesis regarding the origin of these paralog gene pairs, the hypothesis of a 4R whole genome duplication is among the most parsimonious. Several of these duplicated genes were involved in reproduction and the onset of puberty. Regardless of the origin, further analysis of these genes may reveal eel specific adaptations, which could help to better understand the exceptional reproductive system of eels.
Rozenfeld, C. (2019). Development of innovative methods for induction of European eel (Anguilla anguilla) spermatogenesis [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/125697
TESIS

The macroscopic laws of diffusion were laid down for the case of liquids by Adolf Fick 150 years ago who realised the analogy of diffusion and heat conduction. 100 years ago Einstein and Smoluchowski put up the equation named after these scientists teaching us how to trace down the motion of a single diffusing particle and thus to understand long time unexplained Brownian motion as a fluctuation phenomenon. In the last fifty years these laws and their combination were boldly but successfully applied to the diffusion, migration, dispersion of single atoms, men, animals and ideas. We start by showing how the Einstein-Smoluchowski equation makes possible to induce diffusivity from microscopic information on details of the diffusion jump in solids. We then report on Brownian motion and diffusion of our fore-fathers in the Neolithicum following Cavalli-Sforza’s ideas and show how this diffusion must have been a mixture of demic diffusion, i.e. the diffusion of people, and the diffusion of technological ideas. Next we risk a glimpse to the immigration of early Americans. We point out the discrepancy a physicist faces in the conclusions of the Archaeologists. We finally discuss the ultra-fast dispersion of the horse-chestnut leaf miner throughout Europe following recent work of ecologists.

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A movimentação dos organismos pode ser considerada uma resposta comportamental mensurável, resultante da combinação de fatores ambientais, estados internos e restrições fisiológicas. O objetivo deste trabalho foi avaliar e caracterizar os diferentes padrões de movimentação realizados pelas baleias jubarte (Megaptera novaeangliae), em relação ao gênero e o papel social. Dados de localização por telemetria satelital foram filtrados e modelados pelo Modelo de Estado e Espaço (State-Space Model). A rota obtida foi divida em área de alimentação e rota migratória, considerando como limite a isóbata de 500m. A partir disso, foram calculados os ângulos de virada e as frequências com que ocorrem para o lado direito e esquerdo, utilizando o programa ArcGIS 9.3 e o programa livre R. As médias das angulações variaram significativamente, tanto para o lado esquerdo, quanto para o lado direito na análise comparativa das duas áreas, considerando conjunto total dos grupos. Fêmeas com filhote apresentaram valores de significância maior para ambos os lados, enquanto machos exibiram angulações mais proeminentes para o lado direito. A frequência média relativa de virada para a direita e para a esquerda, mostraram-se significativamente diferentes quando comparadas entre machos, fêmeas e fêmeas com filhote, na área de reprodução, bem como o papel social. Animais categorizados como mães, realizaram mais viradas para ambas as direções, em relação à acompanhantes e animais adultos sem presença de filhote. Concluímos que os animais, quando na área de alimentação, realizam movimentos mais irregulares e que fêmeas apresentam mais variação na movimentação quando associadas a filhotes. Novas ferramentas devem ser associadas à técnica de telemetria para obtenção de dados de fina escala, a fim de avaliar de forma mais apurada a movimentação dos animais.
Organisms movements may be considered a measurable behavioral response which outcomes from a combination of environmental factors, internal states and physiological restrictions. In this work, our goal was to evaluate and characterize the different patterns of movements of humpback whales (Megaptera novaeangliae Borowski, 1781), regarding gender and social role. Location data obtained with satellite telemetry were filtered and patterned by State - Space Model. The obtained route was divided in feeding area and migration route going from the isobath of 500 m. In this context, the turning angles and their frequencies to the right and to the left were calculated using ArcGIS 9.3 and the open source software R. The average angulations varied significantly, both to the left and right sides, in the comparative analysis of the areas regarding the whole group. Females with calf showed more significant differences to both directions, while males presented more prominent angles to the right side. The average frequencies for the moves facing right and left turned out to be significantly different when correlated between males, females and females with calf, in the reproduction areas, as well as the social role. Animals categorized as mothers presented more turns to both directions, when compared to companions and adult animals without calves. We have concluded that when the animals are in feeding area, they present more irregular movements and that females with calf are the ones with the highest movement variation. New tools should be associated with the satellite telemetry in order to obtain fine scale data providing a more accurate form to evaluate the animal movement.

Les perturbations de l'hématopoïèse peuvent mener au développement d'une leucémie mais les voies moléculaires jouant un rôle dans la leucémogenèse ne sont pas encore identifiés. Les traitements actuels des leucémies myéloïdes aigus (LMA) ne permettent pas d'éradiquer complètement les cellules leucémiques de la moelle osseuse chez certains patients ce qui fréquemment entraîne une rechute après le traitement de ces patients. Un modèle animal reproduisant la rechute d'une leucémie LMA a été utilisée pour étudier in vivo les événements initiaux qui se produisent lorsque les cellules leucémiques prolifèrent dans la moelle osseuse. Nous avons suivi in vivo, par endoscopie confocale, les étapes précoces d'initiation d'une leucémie dans la moelle osseuse des fémurs de souris Svl29 non-conditionnées après l'injection de 1000 cellules leucémiques syngéniques exprimant la protéine de fusion MLL-ENL (Mixed Lineage Leukemia-Eleven Nineteen Leukemia). Nous avons distingué deux phases au cours du développement de la leucémie : 1) une phase de latence, avec une prolifération faible et un nombre stable de cellules leucémiques détectables dans les fémurs, 2) une deuxième phase caractérisée par une prolifération des cellules leucémiques à l'intérieur de la diaphyse, puis une invasion progressive des épiphyses et des organes périphériques. Les expériences dans des souris conditionnées par y-irradiation ou celles de compétition entre cellules leucémiques dans des souris non-conditionnées ont indiqué que la prolifération mais pas la prise de greffe est un facteur limitant à la propagation des cellules leucémiques dans les épiphyses. Ces cellules leucémiques forment des grappes en bordure des vaisseaux sanguins et de la partie osseuse dans la diaphyse. Des cellules lymphoïdes B220+ ont été retrouvées au voisinage de ces grappes concomitamment à une diminution du nombre de cellules B220+ IgM+ dans les fémurs. Ainsi, l'invasion des cellules leucémiques MLL-ENL s'initie préférentiellement dans la diaphyse des fémurs et est précédée par des changements des populations lymphoïdes B. Ce travail in vivo a permis de montrer une activité suppressive de la population leucémique à rencontre de cellules hématopoïétiques normales au cours du développement d'une leucémie grâce à l'observation in situ des blastes leucémiques dans leur environnement naturel
Hematopoiesis disturbances can lead to the development of leukemia and molecular pathways playing a role in leukemogenesis are not identified yet. Actual treatments for acute myeloid leukemia (AML) do not allow to eradicate efficiently the leukemic cells in some patients and relapse can be observed after the treatment. An animal model mimicking leukemic AML relapse was used to investigate the in vivo initial events that occur when leukemic cells start to proliferate inside the bone marrow. We have followed by in vivo fiberoptic confocal endoscopy the early steps of femoral bone marrow invasion after rétro-orbital injection into non-conditioned 129/Sv mice of 1000 syngenic fluorescent leukemic cells expressing MLL-ENL (Mixed Lineage Leukemia-Eleven Nineteen Leukemia) fusion protein. We have observed that two phases can be distinguished during leukemia development: 1) the latency phase, with a weak proliferation and a stable number of leukemic cells detectable inside the femurs, 2) a second phase characterized by a prolifération inside the diaphysis, followed by a progressive invasion of epiphyses and a further invasion of peripheral organs. The conditioning of recipient mice with y-irradiation and leukemic competition experiments done with non-conditioned mice have indicated that prolifération but not engraftment is a rate-limiting factor of leukemic cells spreading in the epiphyses. These leukemic cells form clusters edging blood vessels near bone surface in diaphysis. B220+ lymphoid cells were found in the vicinity of these leukemic cells clusters and this association is correlated with a decrease number of femoral B220+IgM+ cells. Thus, MLL-ENL leukemic cell burden preferentially initiates in femoral diaphysis and is preceded by changes of femoral B lymphoid populations. This work allowed to show in vivo a suppressing activity of leukemic population on normal hematopoietic cells during leukemia development by the direct observations of leukemic blasts in their natural host environment

Vivre en groupe implique une cohésion et une synchronisation des activités des membres d’un groupe. Dans ce contexte, des individus avec des besoins pouvant être différents doivent décider conjointement où et quand se déplacer collectivement. Alors que les comportements de recrutement et de vote ont été relativement bien étudiés chez les primates et que les processus auto-organisés ont été démontrés dans des grands groupes, peu de chercheurs ont étudié l’existence de processus simples dans des petits groupes structurés d’individus aux capacités cognitives avancées. De même, alors qu’il a été démontré que les relations sociales d’une espèce conditionnaient la forme de certains comportements tels que les comportements d’agression, de réconciliation ou de toilettage, aucune étude n’a démontré cette influence sur le type de consensus d’une espèce. Afin de tester ces différentes hypothèses, j’ai étudié deux espèces de macaques au style social contrasté, le macaque rhésus (Macaca mulatta) ayant une hiérarchie stricte et un népotisme élevé et le macaque de Tonkean (M. Tonkeana) connu pour être tolérant. Les résultats de cette thèse montrent donc l’existence conjointe de processus auto-organisés et de processus plus complexes et intentionnels chez les macaques. Ils démontrent également l’influence du système social sur la prise de décision collective, en termes de dominance et de parenté. Le macaque de Tonkean présente un consensus équitablement partagé et les membres du groupe s’organisent au sein du déplacement en fonction des relations affiliatives, contrairement au macaque rhésus pour lequel le consensus ne semble que partiellement partagé, en faveur des individus dominants et l’organisation des individus biaisée en faveur de la parenté
Living in groups involves group cohesion and synchronization. In this context, animals with different needs have to decide collectively about the time and the direction to move. In Primates, studies mainly focused on intentional behaviours such as recruitment, while in large groups they showed the existence of auto-organised processes. Few studies however have been carried out to prove the existence of these self-organised processes in highly structured groups as primates’ ones. In the same way, studies showed how social relationships of group members constrained behaviours like aggressive, conciliatory or grooming ones but we don’t know how these social relationships influenced the kind of consensus in a species. In order to test these hypotheses, I studied two macaque species with contrasted social style, the rhesus macaque (Macaca mulatta) having a strict hierarchy and a high nepotism and the Tonkean macaque (M. Tonkeana) known to be tolerant. Results of this thesis showed the existence of both auto-organised processes and more complex ones in these stable small groups with individuals demonstrating relatively complex cognitive abilities. Results also proved the influence of the social style of a species, in term of dominance and kinship, on the consensus. Tonkean macaques displayed an equally shared consensus and group members are organised according to affiliation during a collective movement. Conversely, rhesus macaques displayed a partially shared consensus in favour of high-ranking individuals and the organisation of individuals was biased in favour of kinship

Inventaire de la population d'acridiens. Etude de l. Adaptation des especes a differents habitats. Evaluation de l'efficacite des pieges lumineux avec prise en compte de l'eclairement lunaire. Observation de migrations. Etude des fluctuations demographiques par la mise en evidence des facteurs influencants les stades de developpement

Population structure and vital rates of Gulf of Maine (GOM) humpback whales, Megaptera novaeangliae, were studied by a combination of longitudinal data, region-wide surveys and modern mark-recapture statistical methods. Demography and rates of exchange were examined among six GOM areas. Juveniles and females were preferentially encountered in southern GOM habitats, including at the Studds Stellwagen Bank National Marine Sanctuary (SBNMS). Multi-state modelling also revealed unequal probabilities of movement between areas that was not explained by inter-area distance, adjacency, whale density or dominant prey type. Aerial surveys and photo-identification data indicated that the population was likely closed to migration between June and September. Otherwise, seasonal trends in population composition were consistent the demographically staggered migration reported in other oceans. Over-wintering occurred,but there was little evidence that a significant number of humpback whales failed to undertake or complete migration each year. Vital rates varied with sex, age and time. Juveniles exhibited lower and more variable survival than adults and so were a potential source of downward bias in “non-calf” survival estimates. Males exhibited higher survival than females and achieved maximal survival at age five, the estimated age at male puberty. By contrast, females did not reach peak survival until the current average age at first birth (8.78 years, s = 2.33). The latter was significantly higher than previous estimates and females that recruited by age seven had a lower likelihood of subsequent survival than those that recruited late. Costs of reproduction persisted into adulthood, with breeders exhibiting lower survival than nonbreeders. Calves born during years of low fecundity exhibited lower survival than those born when fecundity was high, possibly due to lower maternal investment. Costs of reproduction have not previously been described in cetaceans, but are consistent with the risks potentially associated with capital breeding.

El rorcual común (Balaenoptera physalus) es una de les especies de misticeto más abundante en el Atlántico Norte y es considerada como una especie de alta importancia ambiental por la legislación española. Sin embargo, aún quedan grandes lagunas de conocimiento en la biología de esta especie, especialmente durante el invierno. El objetivo global de esta tesis es la mejor comprensión de la estructura poblacional y las migraciones del rorcual común mediante el análisis de marcadores químicos en tres tejidos diferentes. En el primer capítulo, se analizaron alquenonas en la grasa hipodérmica y en el contenido estomacal de rorcuales de Islandia y del noroeste español. Las alquenonas son moléculas orgánicas producidas por organismos haptófitos que pueden ser usadas para estimar la temperatura del agua donde han sido sintetizadas. Los resultados muestran que estas moléculas pueden ser transferidas a lo largo de la red trófica y ser detectadas tanto en el contenido estomacal de los rorcuales como en la grasa hipodérmica. Mientras la temperatura estimada en el contenido estomacal refleja la temperatura ambiental de los 10 días antes del muestreo, las alquenonas de la grasa hipodérmica parecen reflejar la temperatura del hábitat de los rorcuales durante el invierno. Los rorcuales de las dos áreas estudiadas mostraron una composición de alquenonas bien diferenciada, lo que indica que se trata de poblaciones segregadas. En el segundo capítulo se analizaron los isótopos estables en aminoácidos muestreados en las barbas de ballena. Se observó que el nivel trófico de los rorcuales se vuelve más alto y variable durante el invierno, lo que podría indicar que esta especie complementa su dieta con pescado durante esta época. Además, los valores isotópicos ambientales del invierno sugieren que los rorcuales pasan la época invernal en zonas de emergencia de agua profunda, las cuales pueden sostener una producción primaria mayor que el resto del océano oligotrófico. En el tercer capítulo se midió la consistencia temporal de los isótopos estables en los conos auditivos de los rorcuales. Estos mostraron que los rorcuales son especialistas individuales, es decir los individuos ocupan una porción del nicho poblacional disponible. En conjunto, los stocks estudiados de rorcual común del Atlántico Norte parecen ser más generalistas durante el invierno, pero los individuos parecen migrar y alimentarse en zonas concretas cada año, caracterizadas por una alta producción primaria.
Fin whales (Balaenoptera physalus) is one of the most abundant mysticete species in the North Atlantic, and it is considered a species of high environmental importance by the Spanish legislation. However, large knowledge gaps exist in the biology of this species, especially in winter. The main goal of this thesis is to improve our understanding of the migrations of the fin whale analyzing chemical tracers in three different tissues. In the first chapter, alkenones were analyzed in blubber and the stomach content of the fin whales from Iceland and the NW of Spain. The alkenones are a group of organic molecules produced by some haptophyte species, and may be used to infer the water temperature where they were synthesized. The results show that these molecules can be transferred through the trophic web and detected both in the stomach content and the blubber of the whales. While the temperature estimated in the stomach content reflected the environmental SST 10 days before the sampling date, the alkenones in the blubber reflected the environmental temperature where the fin whales had roamed during winter. In the second chapter, the stable isotopes of amino acids were analyzed in baleen plate samples. The results showed that the trophic level of the individuals were higher and more variable during winter, which could indicate that they were including fish in their diet during the winter season. Furthermore, the baseline isotopic values suggested that the fin whales spent the winter season in zones of deep water emergence, which can support a higher primary production than the oligotrophic ocean. In the third chapter, the temporal consistency of the stable isotopes was measured in the earplugs of fin whales. The results showed that the fin whales are individual specialists, this is, they occupy a small portion of the population isotopic niche. Overall, the fin whale stocks studied in this thesis are more generalist during winter than during summer, however, the individuals tend to migrate and feed in specific zones every year, which are characterized by a high primary production.