Добірка наукової літератури з теми "Snow animals"

Snow cover can significantly impact animal movement and energetics, yet few studies have investigated the link between physical properties of snow and energetic costs. Quantification of thresholds in snow properties that influence animal movement are needed to help address this knowledge gap. Recent population declines of Dall’s sheep (Ovis dalli dalli Nelson, 1884) could be due in part to changing snow conditions. We examined the effect of snow density, snow depth, and snow hardness on sinking depths of Dall’s sheep tracks encountered in Wrangell–St. Elias National Park and Preserve, Alaska. Snow depth was a poor predictor of sinking depths of sheep tracks (R2 = 0.02, p = 0.38), as was mean weighted hardness (R2 = 0.09, p = 0.07). Across competing models, top layer snow density (0–10 cm) and sheep age class were the best predictors of track sink depths (R2 = 0.58). Track sink depth decreased with increasing snow density, and the snowpack supported the mass of a sheep above a density threshold of 329 ± 18 kg/m3 (mean ± SE). This threshold could aid interpretation of winter movement and energetic costs by animals, thus improving our ability to predict consequences of changing snowpack conditions on wildlife.

Animal-borne tracking devices have generated a wealth of new knowledge, allowing us to better understand, manage and conserve species. Fitting such tracking devices requires that animals are captured and often chemically immobilized. Such procedures cause stress and involve the risk of injuries and loss of life even in healthy individuals. For telemetry studies to be justifiable, it is vital that capture operations are planned and executed in an efficient and ethical way. Project objectives must be clearly articulated to address well-defined knowledge gaps, and studies designed to maximize the probability of achieving those goals. We provide guidelines for how to plan, design, and implement telemetry studies with a special emphasis on snow leopards that are typically captured using foot snares. We also describe the necessary steps to ensure that captures are conducted safely, and with minimal stress to animals.

Abstract The snow leopard (Panthera uncia) is commonly seen in the cultural landscape within the Republic of Kazakhstan. This contrasts rather starkly with the endangered species’ presence on the natural landscape there. Three contemporary cultural landscape sightings of the snow leopard in Kazakhstan—the Almaty zoological park, the Kazakhstan 2030 strategy initiative, and the 2011 Asian Winter Games—are explored here. The positive imagery and symbolism linking the snow leopard to the Republic of Kazakhstan cements the non-human animal’s status as an unofficial state symbol. The borderlands of snow leopard landscapes, those spaces of cultural and natural environmental overlap, are vital for conservation efforts. Reincorporating non-human animals into social science research offers the opportunity for cultural landscape investigations. For the snow leopard, cultural landscape research may prove as important as traditional natural landscape research in Kazakhstan and throughout this majestic non-human animal’s territorial range.

Although travel in deep snow imposes high energetic costs, animals can mitigate these costs through behavioural adaptations. For example, they can select habitats with shallower or more supportive snow. It is less well known, however, if animals select for favourable snow conditions at the scale of the step, i.e., along the travel paths themselves. We snow-tracked grey wolves (Canis lupus L., 1758) over 187 km and used a paired design to compare snow conditions on travel paths to snow 1 m and 10 m away. Snow on travel paths was 3.2 cm shallower than measurements 1 m away, except when wolves travelled on linear features recently compacted by humans. In those cases, the mean difference in snow depth increased to 17.5 cm. Our analyses suggest that, under natural snow conditions, wolves are limited in the fine-scale differences they can achieve along their travel paths. By creating areas with highly favourable snow conditions, anthropogenic activities drastically change the winter landscape, with potential implications for energetics and predator–prey dynamics.

Autumnal body mass reduction in a seasonally snow-covered environment is reported for Antechinus swainsonii (Marsupialia: Dasyuridae), thus extending the phylogenetic spectrum in which this phenomenon is known. Above 1600 m altitude the average mass of individual A. swainsonii falls from 48.6 g to 42.6 g (a 12.3% loss) from April to May. The difference in mass results from a reduction in lean mass rather than a metabolisation of fat reserves. In A. swainsonii, the need to increase body mass in late summer only to lose it in autumn prior to a winter beneath the snow seems superfluous. However, the higher mass may be necessary to survive the harsher microclimate in autumn before conditions ameliorate beneath the snow cover. Survival from April to May is higher in heavier animals (that do lose mass in autumn) than lighter animals (with mass in April equal to that of animals after loss of body mass). These lighter animals disappear from the population in autumn. With snow cover in place, A. swainsonii is able to increase mass in winter.

Snow is understood to limit wildlife movements, often being the most important determinant of winter movement for animals in the boreal forest. However, the combined effect of snow and temperature on the movement ecology of animals at high latitudes is less understood. Here, we used GPS-collar data from a small population of wood bison (Bison bison athabascae Rhoads, 1898) in northeastern Alberta, Canada, to develop a series of generalized additive mixed models characterizing the effect of cumulative snow depth, daily change in snow depth, and temperature on movement rates. Our most supported model included cumulative snow depth, temperature, and day of winter. Bison movements decreased in the first 75 days of winter during snow accumulation and dramatically increased in the final 14 days of winter during snow melt. Cumulative snow depth, not daily change in snow depth, reduced wood bison movement rates, and movement rates increased more rapidly in warmer temperatures than in temperatures below −6.4 °C. By quantifying both the direction and the magnitude of snow and temperature’s effects on bison movement, our study fills critical knowledge gaps relating to the winter movement ecology of wood bison and contributes to a growing body of knowledge informing their conservation in the Anthropocene.

Body mass change, water influx, metabolic heat production and rectal temperature were measured in four pregnant beef cows offered only snow as a water source (snow cows) and in four pregnant beef cows that also had access to heated water (water cows). The study was carried out during winter (December to March) in Alberta, Canada. There was no difference between treatment groups in any of these measurements indicating that the snow cows were obtaining adequate water to satisfy their requirements and that no added nutrient energy was required to melt the snow and bring the water to body temperature. Milk yield in the two groups, measured in early spring when water was available to all cows, was similar as was the growth rate of the calves. Milk yield averaged 8.2 kg d−1 during weeks 2–4 of lactation and 4.6 kg d−1 during weeks 14–16. Average daily gain from birth to weaning (6 mo) of calves suckling the snow cows was 0.74 kg and of calves suckling the water cows was 0.70 kg. It was concluded that there was no detrimental effect of withholding liquid water from pregnant beef cows when snow is available and that cows can use snow as their only water source for lengthy periods of time during winter. Key words: Pregnant cows, snow, water, water influx, metabolic heat production

Five calves were denied water for 112 d during winter but had access to snow as a water source (snow calves) and were compared with five calves that had continuous access to water (water calves). All calves were then given continuous access to water for a further 56 d. There was no significant difference between groups in water intake or average daily gain except at the beginning of the 56 d rewatering period when the snow calves drank more water per kg body mass than the water calves. Key words: Calves (weaned), average daily gain, snow, water intake, water influx, tritiated water

Individually (n = 21) and group-fed (n = 100 over two winters) beef cows were either denied water in winter when snow was available or had free access to water. There was no difference in body mass or subcutaneous fat depth between the two treatments nor was there any difference in the birth or weaning body masses of their calves. It was concluded that beef cows could rely on snow as a water source during winter. Key words: Beef cows, snow consumption, body mass change, calf production

Between June, 1982 and October, 1984 traps were laid in the subnivean space of the optimal breeding habitat of Burramys parvus. Mean trapping success during both the snow-free and post-snow periods was more than 12%. No B. parvus were caught in traps set under the snow; the animals either have long periods of torpor and/or their activity is limited to feeding from their food caches, which are presumably located near to the nest (s). Food caches were similar to those of Burramys in captivity. In only one of 14 buildings located within 100 m of B. parvus habitat on Mt Higginbotham was B. parvus trapped during the snow period. In that building, the University Ski Club Lodge (USCL), where the mean trapping success was 28%, 10 females and 13 males were caught. Most of the females were caught during late October. About 50% of animals had been previously tagged during the snow-free period. During the snow period, the number of adult females moving to the USCL was few (8.1% of previous taggings, compared to adult males, 21%). Males returned to female breeding habitat during the breeding season October-November. These data suggest that the Burramys population is sexually segregated during the nonbreeding season.

In order to study sperm competition and mating dynamics in the snow crab Chionoecetes opilio, a genomic library was established with the goal of identifying highly polymorphic microsatellite markers. Six pairs of DNA primers were designed to amplify markers Cop3-4, Cop4-1, Cop5, Cop10, Cop24-3 and Cop111 by the polymerase chain reaction (PCR). All markers produced patterns as expected from single loci inherited in a mendelian fashion, except for Cop5 which revealed a multi-locus banding pattern. The cross-amplification of the six loci in seven additional crabs species revealed DNA polymorphisms at one or more loci for each species. Markers Cop3-4 and Cop24-3 were used to determine paternity of larvae of primiparous females both from the wild and from multiple mating experiments under laboratory settings. The two markers were also used to genotype the contents of female spermathecae in order to determine the number of number of male genotypes present. Spermathecal contents of wild-caught females were cut into several cross-sections and each section genotyped individually. Histological analysis of spermathecae was carried out to complement genetic data in order to elucidate patterns of sperm competition. Single paternity was observed for the progeny of all females. The analysis of laboratory females showed displacement was the mechanism by which single paternity was obtained by the last males to mate. The analysis of wild females revealed that their spermathecae contained on average the sperm of at least 3.7 males. Larvae appeared to be sired by males whose genotypes were found in the spermathecal cross-sections toward the blind-end of the spermathecae. This suggested that they were the first males to mate with females they guarded until oviposition, and females remated with other males thereafter. Also, a comprehensive account of the mating dynamics was carried out in a wild population of the Northwest Gulf of Saint Lawrence (Eastern Canada) and demonstrated the e

A thorough understanding of demographic parameters and their contribution to overall population growth is fundamental to effective conservation of small populations, but this information is often lacking. The Pacific Coast population of the Western Snowy Plover (Charadrius nivosus nivosus) is listed as threatened and has been the target of long-term, multi-pronged management in Oregon. The Oregon coastal population has been intensively monitored since 1990, and over 80% of the population is color banded, but a comprehensive analysis of demographic parameters and the effect of management on vital rates and population growth has been unavailable until now. Here, the author used capture-mark-resight techniques to document survival at each life stage and to explore environmental and management factors that best explained variation in survival over a 25-year study period. The author analyzed the effects of habitat restoration, exclosure use, and lethal predator management on survival at appropriate life stages and evaluated the effects of one management option, lethal predator control, on overall population growth. Chick survival to fledging improved dramatically after the chicks' 5th day, was higher in years with lethal predator management, and was highest during the peak of the long brood-rearing season. Cold weather, particularly during the chicks' first 5 days, had a negative effect on survival to fledging. Juvenile survival from fledging to the following spring declined over the study period, but rebounded after implementation of lethal predator management. Adult survival was lower in wetter-than-average winters and higher in years with predator management. The author used the survival analyses and productivity data collected over 25 years in a matrix population model to reveal that population growth is most sensitive to changes in adult survival, and that while predator management is important for continued growth, its use may be scaled back by as much as 50% and still maintain a growing population. My results, encompassing all phases of this species' life cycle, demonstrate that with holistic and thoughtful adaptive management, and with the cooperation of numerous agencies, a balance can be struck between protection and control of native species to bring about recovery of species threatened with (local) extinction.

Dam building activity by North American Beaver (Castor canadensis) alters the timing and delivery of stream water and facilitates groundwater infiltration, overall increasing natural water storage behind and adjacent to dams. At the stream reach scale, increased water storage often alters hydrologic regimes by attenuating annual, and storm-event hydrographs, and increasing base flows. In the montane west, the most important water storage reservoirs are not human-made dams, but mountain snowpack, which slowly releases water through a mix of runoff and infiltration. Given estimates of decreasing snowpack with warming temperatures, beaver dams could provide a conceptually similar function to snowpack by delaying the delivery of precipitation by increasing surface and groundwater storage, thus lengthening residence time as water travels downstream. However, lack of predictive methods for modeling storage increases associated with relatively small magnitude beaver ponds at large spatial scales has precluded further investigation of this hypothesis. I address this knowledge gap by supplementing existing empirical data regarding the height of beaver dams and implement these empirical height distributions to develop the Beaver Dam Surface Water Estimation Algorithm (Chapter 2), a predictive model estimating beaver pond water storage that can be applied spatially at large scales. I then apply this model to estimate potential surface water storage and parameterize a groundwater model to estimate resulting groundwater storage increases for the entire Bear River basin under four different beaver dam capacity scenarios (Chapter 3). Estimated water storage changes from beaver dams are presented in the context of expected reductions in average annual maximum snow water equivalent, and existing and proposed reservoir storage within the basin. While the water storage provided by beaver dams is only a small fraction of expected snow water equivalent loss, it is not insubstantial and may prove beneficial for ecosystems where human-made reservoirs are not available to regulate hydrologic regimes. These results also stress the importance of further research examining how the cumulative effects of dams may affect the timing of runoff under changing precipitation regimes.

Snowy plovers (Charadrius nivosus) are small, ground-nesting shorebirds that are a species of conservation concern throughout North America. Despite increased efforts to understand factors contributing to the decline of snowy plover, little is known about habitat selection and breeding ecology of snowy plover for the large population found in the Great Basin. We tested hypotheses concerning the occupancy and nesting success of snowy plover. First, we identified factors influencing snowy plover nest survival at Great Salt Lake, Utah. We hypothesized that snowy plover would demonstrate differences in nest survival rates across years due to differences in habitat characteristics, predator abundance, human influence, resource availability, and fluctuating water levels. We conducted nest surveys at five sites along the Great Salt Lake to locate new nests or monitor known nests until nest fate was determined. We found 608 nests between 2003, 2005-2010, and 2012. The most common cause of nest failure was predation, followed by weather, abandonment, and trampling. Nest survival estimates ranged from 4.6 -- 46.4% with considerable yearly variation. There was no correlation between researcher activity (visits to nests and trapping of adults) and nest survival. Nests in close proximity to roads had lower survival than nests far from roads. Nests located on barren mudflats also had lower survival than nests in vegetated areas or near debris. We found that nests had a higher probability of survival as they increased in incubation stage. Because nesting areas around the Great Salt Lake host some of the largest concentrations of breeding snowy plover in North America, we suggest that managers consider measures to maintain suitable nesting habitat for snowy plover. Second, we determined factors affecting snowy plover occupancy and detection probabilities in western Utah between 2011 and 2012. We hypothesized that snowy plover would be associated with spring water flows and sparsely vegetated salt flats. We made repeated visits to randomly selected survey plots recording the number of snowy plover adults and habitat characteristics within each plot. We modeled the relationship between snowy plover detection probability and habitat and environmental characteristics. The detection probability was 77% (95% CI = 64 -- 86%) and did not vary by year. There was a positive relationship between ambient temperature and detection probability. Next, we modeled the relationship between snowy plover occupancy and individual habitat characteristics including distance to water, distance to roads, land cover types, and vegetative characteristics. Snowy plover occupancy did not vary by year and was estimated at 12% (95% CI = 7 -- 21%). Occupancy was best predicted by close proximity to water, playa land cover, and minimal shrub cover. We used habitat characteristics that best predicted snowy plover occupancy to generate a predictive habitat model that can help prioritize future snowy plover surveys and guide conservation efforts.

Research in animal personality has been increasing over the last decade, as scientists realise its importance to a variety of health outcomes. In particular, personality has been shown to have an effect on immune function, stress, infant survival, overall well-being, morbidity, and mortality. Because of this, personality can play an important role in captive management, especially as stress is often a problem for captive animals. Research has already shown that personality affects captive breeding efforts, enclosure grouping, and stress regulation in some species. Only a few studies have focused on felids, but these have shown that there are possible applications for personality in that taxon. Because most felids are endangered, and because many of them face special challenges in captivity due to their size and biology, this work aimed to increase knowledge on felids, using personality as a framework, with implications for captive management as a target. Focusing on five species, I assessed the personality of domestic cats, Scottish wildcats, clouded and snow leopards, and African lions, and the well-being of the four latter species. With the exception of the domestic cat, there has been little to no personality work in these species, and none on well-being. I then compared the data within and among these species. I found three main personality factors among the species, including dimensions I labelled Neuroticism, Dominance, and Impulsiveness, with some differences, including an Agreeableness factor in some species, and elements of Openness. As in other species, well-being was negatively related to Neuroticism in most of the study species. Taking into consideration each species’ biology, natural history, and genetics, I discuss the implications and importance of using these species’ personality and well-being assessments in both captive management and conservation efforts. The results indicate that, like in humans, a targeted, individual approach to care is the best use of personality for captive animals.

Pour la grande majorité des grands herbivores vivant en régions tempérées, l'hiver est la saison la plus limitante à cause des effets combinés du manque de ressources et de la sévérité des conditions climatiques. Les espèces qui ne développent pas d'adaptations morphologiques ou physiologiques particulières pour faire face à la sévérité de l'hiver doivent mettre en place des mouvements et des tactiques d'utilisation de l'espace appropriés (comme par exemple les migrations). Plus spécifiquement, ces patrons d'utilisation de l'espace peuvent émerger à différentes échelles spatio-temporelles pour permettre aux individus d'accéder aux ressources dont ils ont besoin et d'échapper aux conditions climatiques défavorables. Ainsi, ces patrons d'utilisation de l'espace déterminent le sort des individus et la dynamique des populations. Une compréhension détaillée de la relation entre les facteurs limitants durant l'hiver et la réponse des animaux en termes de mouvements est prépondérante pour préserver et gérer les populations d'ongulés sauvages avec succès, tout spécialement dans le contexte actuel de changements climatiques rapides qui induisent des modifications importantes dans le paysage et la distribution des ressources (par exemple changement de patrons de couverture neigeuse en hiver). La comparaison de tactiques de mouvements sous différents scénarios de conditions environnementales, par exemple au moyen d'analyses à vaste échelle de l'aire de distribution de l'espèce cible, représente une approche pertinente pour mieux comprendre comment les mouvements des animaux répondent aux changements dans le paysage. Le chevreuil (Capreoluscapreolus) est une espèce modèle particulièrement intéressante pour étudier ces questions parce que la distribution de cette espèce couvre la plupart des pays d'Europe, grâce à sa forte plasticité écologique
For the majority of large ungulates living in temperate regions winter is the limiting season, because of the combined effects of lack of resource availability and severity of climatic conditions. Those species that did not develop any particular morphological and physiological adaptation to cope with winter severity may adopt movement and space use tactics instead (like e.g. migration). Specifically, these space use patterns may emerge at different spatiotemporal scales to allow individuals to accede the resources they need and escape unfavourable conditions, thus determining both individual fate and population dynamics. A detailed understanding of the relationship between limiting factors in wintertime, and individual movement response, is remarkable to preserve and manage wildlife successfully, especially in the context of fast-occurring climate change that induces important alterations in landscape and resource distribution (e.g. changes of snow cover patterns). The comparison of movement tactics under different environmental scenarios, e.g. by means of large –scale analysis at the species distribution range, represents a valuable approach to work in that direction and to assess the effects of landscape alteration on individual movement. Roe deer (Capreolus capreolus) is an excellent model species to investigate these issues, because its distribution range covers most of Europe, thanks to its high ecological plasticity. For those populations that live in northern and mountain environments, winter is the limiting season because roe deer lack any morphological and physiological adaptations to cope with winter severity. In spite of the adoption of specific movement tactics such as partial migration from summer to winter ranges, roe deer may still face limiting conditions in some areas of the distribution range exposed to winter severity

Chez les espèces longévives, une relation inverse entre la variabilité des paramètres démographiques et leur élasticité (i.e. la contribution relative du paramètre au taux de croissance de la population) semble exister. La théorie de la canalisation environnementale permet d’expliquer une telle relation. Les paramètres ayant la plus haute élasticité auraient évolué de façon à être moins variable face aux variations environnementales afin d’optimiser la fitness individuelle et ainsi maximiser la croissance de la population. Afin de tester l’existence d’une telle hypothèse chez une espèce, il est nécessaire d’estimer les paramètres démographiques ainsi que leur contribution relative au taux de croissance. À l’aide des modèles les plus récents de capture-marquage-recapture, nous avons donc estimé les paramètres de survie juvénile et de reproduction chez la grande oie des neiges pour les comparer au taux de survie adulte, paramètre le plus élastique. Notre étude a montré que les paramètres de survie juvéniles et de probabilité de nicher étaient très variables, tel qu’attendu. Le taux de survie juvénile dépend des conditions environnementales, avec notamment un fort effet du parasitisme. En vermifugeant des individus, nous avons trouvé un effet négatif des parasites intestinaux sur la survie des oies juvéniles femelles mais pas sur celle des mâles, ce qui s’explique probablement par une différence d’investissement dans le système immunitaire en fonction du sexe chez les individus en croissance. La probabilité de nicher est aussi dépendante des conditions environnementales mais notre étude a également révélé l’existence de coûts associés à la reproduction. En effet, la probabilité de nicher l’année suivante était fortement réduite suite à une reproduction avec succès comparé aux individus qui avaient eu un échec. Par contre, parmi les individus qui nichent, ceux qui avaient du succès l’année précédente avaient plus de chance d’avoir à nouveau du succès l’année suivante que ceux qui avaient eu un échec, ce qui suggère une hétérogénéité dans la qualité des individus. En parallèle de ces estimations, nous avons montré que le taux de survie adulte était constant au cours du temps et indépendant du statut reproducteur l’année précédente. Finalement, nous avons également trouvé que la survie adulte ne différait pas entre 2 colonies situés à 800 km de distance dans l’Arctique canadien, ce qui suggère une faible variabilité spatiale pour ce paramètre démographique. Notre étude a donc démontré la faible variabilité temporelle et spatiale du paramètre démographique le plus important pour le taux de croissance de la population, contrairement aux autres paramètres qui montrent une forte variabilité chez la grande oie des neiges. Notre étude permet donc d’appuyer la théorie de la canalisation environnementale des paramètres démographiques chez les espèces longévives.
In long-lived species, an inverse relationship apparently exists between variability of demographic parameters and their elasticity (i.e. the relative contribution of a given parameter to the population growth rate). The environmental canalization theory has been proposed to explain such a relationship. Demographic parameters with the highest elasticity should have evolved in a way that reduces their variability in presence of environmental variations in order to optimize individual fitness and hence to maximize the population growth rate. To test this hypothesis in a given species, demographic parameters and their elasticity need to be accurately estimated. Using advanced capture-mark-recapture models, we estimated juvenile survival and breeding probabilities in the greater snow goose and we compared their variability to adult survival, the parameter with the highest elasticity. Our study showed that both juvenile survival rate and breeding propensity were highly variable, as expected. The juvenile survival probability varied in response to environmental conditions, with a strong impact of parasitism. An anthelmintic drug treatment applied to juveniles revealed a negative effect of intestinal parasites on survival of juvenile females but not males, which could be explained by a sex-differential investment in the immune system in growing individuals. We found that the breeding propensity also varied with environmental conditions but we also found some evidence for costs of reproduction. Breeding propensity in the following year was greatly reduced after a successful reproduction compared to birds that had a failed attempt. However, among birds that bred, those that had a success the year before were more likely to be successful again the following year than those that had failed, which suggests heterogeneity in individual quality. In those studies, we showed that adult survival was constant over time and independent of the breeding status the year before. Finally, we also found that adult survival did not differ between 2 breeding colonies distant of 800 km in the Canadian Arctic, which suggests a low spatial variability for this demographic parameter. We thus demonstrated a low temporal and spatial variability in the most important demographic parameter for population growth, which contrasts with the high variability of other parameters in the greater snow goose. Our study supports the environmental canalization theory as applied to demographic parameters in long-lived species.

Le développement post-natal est une étape cruciale pour le reste de la vie d’un individu car c’est à ce moment que sont finalisées et maturées les fonctions physiologiques et comportementales individuelles et que la morphologie finale est acquise. Toute contrainte ou tout stress perçu par la progéniture pendant cette période peut avoir des conséquences morphologiques, physiologiques et/ou comportementales non négligeables à court mais aussi à long terme. In fine, c’est alors sa fitness qui peut être affectée par la qualité des conditions de développement subies. Ce doctorat vise à améliorer notre compréhension de l’importance des conditions environnementales abiotiques (climat, dérangement anthropique et exposition à un pesticide) et des soins parentaux rencontrés durant la croissance sur la qualité des poussins produits. Grâce à l’étude des marqueurs du stress et de l’allostasie (réponse au stress et longueur des télomères) chez des poussins d’Albatros à sourcils noirs et de Pétrel des neiges, nous avons pu démontrer, dans un premier temps, qu’à court terme, la qualité des soins parentaux – approximée par l’âge des individus reproducteurs – était un facteur très important pour la mise en place du phénotype du poussin. Dans un second temps, la manipulation des taux de corticostérone durant le développement chez des poussins de Moineau domestique (mimant une contrainte développementale) semble impacter à long terme les performances individuelles. En effet, à l’âge adulte, une réduction du métabolisme et des dépenses énergétiques, une réduction de l’attractivité sexuelle et une augmentation de l’investissement parental ont été mis en évidence. Au vu des résultats obtenus dans le cadre de ce doctorat, nous discutons de l’influence des conditions de développement sur la fitness des individus en s’appuyant sur les hypothèses évolutives détaillées dans la littérature scientifique
Post-natal development is a crucial step for the rest of life. Indeed, individual physiological and behavioral functions are set-up and matured during that life-stage and final morphology is acquired at that time. Any stress or constraint perceived by the offspring during this period can have significant morphological, physiological and/or behavioral consequences in the short but also in the long term. In fine, an individual’s fitness can be affected by the quality of its developmental conditions. This PhD aims to improve our understanding of the impact of abiotic developmental conditions (climate, human disturbance and exposure to a pesticide) and parental care on the quality of the produced chicks. Firstly, through the study of markers of stress and allostasis (stress response and telomere length) in Black-browed albatross and Snow petrel’s chicks, we demonstrated that in the short term, the quality of parental care - approximated by the age of the breeding individuals - was a major factor determining a chick’s phenotype. Secondly, the manipulation of corticosterone levels during development in House sparrow chicks (mimicking a developmental constraint) seems to have long-term impacts on individual performance. More precisely, in adulthood, I found that this experimental manipulation of developmental conditions was associated with a reduced metabolism, a reduced sexual attractiveness, and an increased parental investment during adulthood. Using the results obtained during this PhD, I discuss the influence of developmental conditions on individual fitness in an evolutionary context

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

Snow is an important factor in the lives of flora and fauna in those regions where it occurs. Despite this, there is a relative lack of information about the ecological role of snow. In addition, on a global scale the majority of the research on snow ecology has been based in the boreal regions of North America and Eurasia. Insights from these areas may not extrapolate well to Australia. The distribution and physical characteristics of snow are highly variable both temporally and spatially. Its occurrence is affected by a range of factors acting at multiple scales. Working in snow covered areas, however, presents considerable practical problems, particularly for researchers attempting to sample organisms in the subnivean space between the base of the snowpack and the ground surface. As a result, most research has focused on small-scale projects because of logistical and animal-welfare issues. A technique was developed for this study for sampling small mammals beneath the snow using hairtubes fitted with bait and a removable adhesive surface that could be inserted into the subnivean space through a vertical PVC pipe. The technique provided a 39% detection rate with only 0.2% of tubes visited but not collecting hair samples. Using. this technique, it was possible to expand systematic sampling of small mammals in the subnivean space to larger scales at which snow cover can vary spatially and temporally particularly at the landscape scale. The main part of this research was conducted over two winters (2002-2003) at sites established in a series of valleys close to the Summit Road in Kosciuszko National Park, south-eastern Australia. Selection of sites was based on factors considered important in influencing the distribution of snow in the landscape and representative of the key vegetation types occurring in the subalpine zone. The resulting design consisted of 72 sites stratified by elevation (1501-1600 m, 1601-1700 m, 1701-1800 m), aspect (accumulating, ablating) and vegetation type (woodland, wet heath, dry heath, grassland) with each combination replicated three times. Each site consisted of three hairtube plots approximately 10 metres apart, at which small mammals were sampled. In addition, a range of biotic and abiotic factors including snow cover characteristics were measured throughout the winter at these same sites. In January 2003, a major bushfire burned 70% of the subalpine area of Kosciuszko National Park and damaged 83% of the sites established in 2002. As a result sampling during winter 2003 was limited to high elevation sites, along with a fifth habitat type (boulderfields). The snow cover that occurs in the main alpine and subalpine region of the· Snowy Mountains is primarily maritime in areas where there is sufficient accumulation, and ephemeral at lower elevations and ort higher ablating aspects. Maritime snow is generally deep (> lOOcm), with a density >0.30gcm-3, as a result of destructive metamorphism throughout the winter. The formation of depth hoar, which is considered to be important in acilitating the development of the subnivean space, does not occur under these conditions. Ephemeral snow is characterised by warm shallow snow that often melts before new snow is deposited. When snow was present, detections of dusky antechinus, Antechinus swainsonii and the bush rat, Rattus fuscipes were negatively correlated with snow depth and duration, and positively correlated with the complexity of structures and microtopography. At high elevations, detections were largely confined to boulderfields, and at mid- and low elevations, small mammals were detected primarily in habitats where the subnivean space was most extensive. Antechinus swainsonii and R. fuscipes responded differently to snow cover with the latter seeming better able to overwinter where snow cover was shallow and patchy. In contrast, A. swainsonii occurrence was correlated with the size of the subnivean space. The development of the subnivean space in the Snowy Mountains is dependent on the presence of structures such as shrubs, boulders and microtopographic features that are capable of supporting a snow layer above ground level. The temperature in the subnivean space was virtually constant beneath the snowpack, ranging between 0 and + 1 °C. When snow was patchy or absent, temperatures at ground level were highly variable with a minimum as low s -13°C and maximum as high as +47.5°C. Antechinus swainsonii and R. fuscipes were detected more regularly at sites that were thermally variable. At sites with deep and persistent snow cover (maritime snow), subnivean temperatures were stable, but small mammals were detected at low frequencies. At high elevations, boulderfields were favoured by small mammals during the nival period but were no different thermally from other habitats. The limitations imposed by snow cover on small mammals were further verified by a radio tracking study conducted during 2003 at Perisher Creek. That study investigated the home range size and activity patterns of R. fuscipes and A. swainsonii in relation to snow cover. Once continuous snow cover became established, the home range of both species contracted dramatically and there was an increase in home range overlap. Neither species showed any change in diurnal activity patterns. Rattus fascipes showed signs of social interaction during both seasons in contrast to A. swainsonii, which appeared to remain solitary. In winter, R. fuscipes nested communally at a single location, while during autumn the species appeared to use a number of nest sites. There was no significant change in daily activity patterns between autumn and winter in either species. R. fuscipes remained primarily nocturnal during both pre-nival and nival periods while A. swainsonii continued to be active throughout the diel cycle, although there was a slight shift in its peak activity time. Human activities can, have significant effects on the subnivean space and its residents. The physical characteristics of a range of modified snow types were investigated in the vicinity of several ski resorts in Kosciuszko National Park. Human activities associated with snow-based recreation, such as the creation of ski pistes, surface ski lifts and over-snow routes, involve compression of the snowpack and resulted in small or absent subnivean spaces and high snow cover densities compared to unmodified snow cover. To test the effects of the loss of the subnivean space on small mammals, the snowpack was experimentally compressed in high quality subnivean habitats. Detections of R. fascipes and A. swainsonii declined by 75-80%. Burnt sites from the 2002 study were used in 2003 to investigate the effect of removing vegetation on the subnivean space, to simulate the loss of structure associated with ski slope preparation. There was a significant reduction (p<0.0001) in the size of the subnivean space compared to unburnt sites regardless of habitat type. The key conclusions of the work reported in this thesis are listed below: • Snow conditions in the Australian Alps are markedly different from those of higher northern latitudes and altitudes. As a result, conclusions about snow/fauna interactions based on research in regions with particular snow cover types need to be carefully considered before attempting to extrapolate generalisations to other parts of the world. • The subnivean space can be formed either by passive or active processes. The former occurs when there are sufficient competent structures to permit the support of the snow pack above the ground surface, while the latter refers to the ability of small mammals to actively tunnel through relatively low density snow (depth hoar) and thus create their own subnivean space. In Australia the passive process dominates. • The widely held assumption that small mammals are dependent on the thermally stable conditions in the subnivean space was not confirmed. Rattus fascipes and A. swainsonii survive in the Australian Alps because they are able to exploit thermally variable environments. • Management of human activities in nival areas should focus on avoiding disturbance in areas where a subnivean space forms, particularly in high quality winter habitats such as boulderfields. • Global warming resulting from climate change is likely to provide conditions in the Australian Alps that favour an expansion of the distribution and population of R. fuscipes and A. swainsonii, but nival endemics such as Burramys parvus and possibly Mastacomys fuscus may be at a disadvantage. • The extent of alpine and subalpine environments in Australia will decrease in future, imposing greater pressure on a shrinking resource and raising the possibility of conflict between user groups and conservation imperatives.

When the ponds were firmly frozen, they afforded not only new and shorter routes to many points, but new views from their surfaces of the familiar landscape around them. When I crossed Flints’ Pond,* after it was covered with snow, though I...

The beaver meadow is quiet in January. For many plants and animals, winter is a season of subdued activity, or of waiting. North St. Vrain Creek remains open along the main channel, the water flowing clear but tinted brown as pine bark between snowy banks. Densely growing thickets of willow closely line the banks. Each stem starts pale brown near the ground, then grades upward to shades of maroon or yellowish orange at the branch tips. In a bird’s-eye view, these startling colors make the meadow stand out distinctly from the dark green conifers that define the edges of the meadow. Spruce and fir trees grow sharply pointed as arrows; pines present a slightly more rounded outline. Snow falls silently in thick flakes from the low, gray sky. The upper edges of the valley walls fade into snow and clouds. The sun appears briefly as a small, pale spotlight behind the clouds to the south. Snow mounds on the patches of ice in the shallow channel. The water flowing beneath creates flickers through the translucent ice like a winter fire of subdued colors and no heat. Tussocks form humps of straw-colored grass above the dark, frozen soil. Rabbit tracks line the snowy bank, sets of four paw marks with a large gap between each set. Something small crossed the bank, leaping one to two feet at a bound, two paws with slight drag marks behind them. In places the powdery snow has drifted deeply, but mostly it is shallow over a frozen crust. Beaver-gnawed sticks and stumps poke up through the snow. A large flood came through four months ago, in mid-September, washing out dams that the beavers have not yet rebuilt. Chunks of wood deposited among the willow stems by the floodwaters stand far above the January flow of the creek. A dipper fishes the creek, wading rather than swimming, at home in the cold water. The slate-gray bird is the only visible animal, busily probing the bed with its short bill, then pausing to stand and bob up and down.

By late November, snow covers much of the beaver meadow. I visit on a sunny day well above freezing, but the low-angle light comes with long, long shadows. The meadow is noisy with continuously rushing wind that keeps the bare willow branches swaying and sculpts the snow on the lee side of plants into streamlined mounds. Individual grass stems have traced downwind crescents on the snow surface. Tracks of wind, tracks of animals: the activities of the meadow are once again made visible in the footprints of moose, hare, squirrel, coyote, and birds. The snow is mushy in the warmth and many of the tracks are blurred, but I also cross fresh, sharply defined traces left by four little leaping paws, with just the brush from a long, slender tail behind them. The prints are so delicate that they barely indent the snow, but clearly a mouse was stirring here recently. The fragile tracery of tiny claws in the snow seems vulnerable, but I know the animal is probably better adapted to the cold than I am. The main channel of the creek remains open, the water golden brown between white banks bulbed with ice along the edges. The creek flows quietly, the sound of moving water submerged beneath the wind. The larger side channels also remain open and green with filamentous algae, but I break through the snow-covered thin ice on the smallest side channels. The off-channel ponds are frozen more solidly. Mats of dried algae quiver in the wind on one newly drained pond. Downwind, the snow is dirty with silt blown from the exposed bed. A layer of sticks, sand, and muck floors the pond with a woody carpet created by the beavers. The main beaver lodge is freshly plastered with mud and sticks, but the ice on the surrounding pond remains unbroken and the snow is trackless. Away from the pond, snow into which I sink to mid-calf obscures the details of the ground. The upright stems of willows and aspen trunks dominate the foreground.

“Home on the Range” evokes a western landscape “where the deer and the antelope play.” But even at the song’s debut in the 1870s, deer and antelope were declining in numbers and cattle grazing was degrading rangelands across the American west. In their natural state, arid North American lands are robust and productive, but they recover exceedingly slowly from heavy grazing. By 1860, more than 3.5 million domesticated grazing animals were trampling arid western soils, causing severe erosion and lowering both water quality and water supplies in a water-poor region. The early start and persistence of grazing over such a long period of time invaded every nook and cranny of the public lands, making livestock grazing the most pervasively damaging human land use across all western ecosystems. Today, grazing affects approximately 260 million acres of publicly owned forest and rangelands, mostly in the 11 western states—about equivalent to the combined area of California, Arizona, and Colorado. Those acres include Pacific Northwest - r and ponderosa forests; Great Basin big sagebrush lands; the richly H oral Sonoran Desert; magni- cent high-desert Joshua tree forests; varied shrub associations in the low-elevation Mojave, Great Basin, Chihuahuan, and other southwestern deserts; and extensive Colorado Plateau pinyon–juniper forests stretching from northern Arizona and New Mexico to southern Colorado and Utah and decorating the arid inland plateaus of Washington, Oregon, and northeastern California. Proponents of public lands grazing argue that cattle have not changed anything. They just replace the immense herds of hooved native herbivores—bison, deer, antelope, and elk—that once dominated western ranges. But in pre-European settlement times, natural forces, including unlimited predators and limited fodder, effectively controlled the native animal populations. Unlike cattle, the herds of deer, antelope, and elk wintered in generally snow-free lowland areas and used much less than their full range each year. And those animals were easier on the land, especially the rivers. Immense bison herds ranged over vast areas, never staying very long on any range. Bison rarely visited the sites of today’s major livestock grazing problems in Great Basin and southwestern deserts, however. On northern ranges, bison obtained winter moisture from eating snow and did not cling to creeks and streams the way cattle do.

Alpine tundra is an intriguing ecosystem—for its beauty as well as for the harsh climate in which it exists. Contrasted against jagged rock precipices and snow and ice and subjected to rapid changes in weather, the tundra, with its proliferation of diminutive flowers, appears deceptively fragile. John Muir, in detailing the alpine of the Sierra Nevada, was at a loss to adequately describe “the exquisite beauty of these mountain carpets as they lie smoothly outspread in the savage wilderness” (Muir 1894). Despite this aesthetic fascination for the alpine, it is one of the least studied ecosystems in the world. Significant effort has been expended to describe the physiological ecology of alpine organisms (e.g., Bliss 1985; Carey 1993; Körner 1999) and community patterns (Komárková 1979; Billings 1988), but there have been no syntheses detailing alpine ecosystem processes and patterns to the degree that they have been described in the arctic (e.g., Chapin 1992) and forest (e.g., Likens and Bormann 1995) ecosystems. The goal of this book is to provide a description of the Niwot Ridge/Green Lakes Valley alpine ecosystem of the Front Range in the Colorado Rocky Mountains, including the spatial and temporal patterns of animals, plants, and microorganisms and the associated ecosystem processes. The book focuses on the strengths of the research carried out on Niwot Ridge during the past four decades, particularly physical factors influencing alpine ecology (climate and geomorphology), patterns and functions of the vegetation, and N biogeochemistry. While the book focuses on a particular site, the results can be extrapolated to much of the southern and central Rocky Mountains, and thus it pertains to a broader geographic and scientific scope and will be of direct interest to ecologists in general as well as to those interested in ecosystems in extreme environments. There are numerous justifications for a synthesis of alpine ecosystem studies. While alpine tundra occupies only about 3% of the global land surface (Körner 1995) and thus has little impact on atmosphere-biosphere exchange, its presence at the extreme climatic tolerance for many organisms and its presence on every continent make it a good “indicator” system for regional environmental change.

Viewed from space by human eyes, the predominant colours of our planet are the blue of the oceans and the white of the clouds. The blue of the oceans forms the subject of another of our chapters. However, if one focuses on the land masses other colours dominate. On land the white colour still features prominently in the polar areas covered with snow and ice, but zoom in on lower latitudes and much of the land is a mix of the green of vegetation and the brown of more arid areas. Green dominates large areas of land, so unless you are reading this in a desert, during the high-latitude winter, or in a highly urban area, then green will probably feature prominently in your surrounding landscape. One answer to the question that heads this chapter is that the climate (often rainfall) allows some parts of the land to be green with plant life, while making other areas arid and brown. However, this green of extensive plant life is still a puzzle—plants are food for a wide range of animals, so why is so much food left unused? Swarms of locusts, destroying most plants in their path (be they biblical plagues or modern day outbreaks), are the exception not the rule. But why is this so? Why are so many parts of our world green in the face of this threat from herbivores? As we will see, if herbivores are the key to our question, then what starts as a question in plant ecology ends up being a question about factors that limit the size of herbivore populations. In effect, we need to understand why herbivore populations do not increase in density to such a level that they destroy all the available plants, giving a land that is brown rather than green. Until the middle of the twentieth century if you had put the green world question to biologists, many of them would probably have suggested that it was not in the interests of a species to consume all of its food reserves.

Pigs belong to a rare group of domestic animals that are bred only for one type of product - meat. There is a difference between open and closed rearing systems in organic pig farming. An open rearing system means keeping sows outdoors during whole year, which means in summer when pigs are exposed to high temperatures and in winter when they are exposed to rain, snow and wind. Therefore, it is recommended to make a shelter in the area where the sows are staying, where they will take shelter from unfavorable weather conditions. The closed rearing system largely limits natural movements and movements, and especially activities due to the urge to digging. The most common systems of facilities for housing sows are two-part, three-part and the so-called stolba pen.

Теоретические и эмпирические исследования показывают, что распределение хищников в значительной степени определяется доступностью основных видов жертв. Доступность зависит не только от плотности населения животных, но также от их уязвимости, на которую влияет конфигурация атрибутов ландшафта, увеличивающих шанс удачной охоты для хищника. Остается плохо изученным то, как именно пространственные вариации в этих процессах формируют модель поведения хищников в масштабах индивидуального участка. В данном исследовании рассматривалось влияние плотности популяций и уязвимости жертв на использование индивидуального участка амурским тигром Panthera tigris altaica на Дальнем Востоке России в течение 20 снежных сезонов. Всего было построено 80 карт, изображающих предсказание относительной плотности населения видов жертв тигра, как по отдельности, так и для всех видов, объединенных в группу, для каждого снежного сезона года в течение 20 лет исследований. Модель, прогнозирующая относительную уязвимость основных видов жертв в зависимости от ландшафта, в основном включала высоту над уровнем моря, близость к поселкам/сельскохозяйственным районам, крутизну склона, средний уровень покрытия снегом, и близость к ближайшим водотокам. Изюбрь, пятнистый олень и кабан чаще всего добывались в местах с более низкой высотой над уровнем моря в удалении от поселков/сельскохозяйственных районов. Кабан оказался единственным видом, для которого уязвимость увеличивалась в местообитаниях с большей высотой снежного покрова. Обнаружено, что амурский тигр в пределах своего индивидуального участка использует места с наивысшей плотностью населения изюбря Cervus elaphus и кабана Sus scrofa. Важнейшую роль в формировании индивидуального участка тигра играет территория, где изюбрь наиболее уязвим для хищничества, а места с наибольшей плотностью населения изюбря используются на периферии участка обитания хищника. Выявлено две стратегии хищнического поведения тигра. Так как распределение ресурсов в пределах индивидуального участка обитания влияет на выживание и размножение хищника, исследование имеет большое значение не только для более детального понимания взаимоотношений в системе тигржертва , но и для сохранения тигра.Theoretical and empirical studies show that the distribution of predators is largely determined by the availability of the main species of prey. Accessibility depends not only on the population density of animals, but also on their vulnerability, which is affected by the configuration of landscape attributes that increase the chance of successful predator hunting. It remains poorly studied how exactly spatial variations in these processes form a predator behavior model on the scale of an individual site. This study examined the impact of population density and prey vulnerability on the home range use by the Amur tiger Panthera tigris altaica in the Russian Far East for 20 snow seasons. A total of 80 maps were constructed depicting the prediction of the relative population density of tiger prey species, both individually and for all species combined for each snow season for over 20 years of research. The model predicting the relative vulnerability of the main prey species depending on the landscape mainly included altitude, proximity to villages / agricultural areas, slope steepness, average snow cover, and proximity to nearby watercourses. Red deer, sika deer and wild boar were most often killed in places with a lower altitude, away from villages / agricultural areas. The wild boar turned out to be the only species for which vulnerability increased in habitats with greater snow cover. We found that the Amur tiger, within its individual home range, used places with the highest population density of the Manchurian deer Cervus elaphus and wild boar Sus scrofa. The most important role in the formation of tiger individual home range had area where red deer was most vulnerable to predation, and places with the highest density of red deer used at the periphery of individual home ranges. Revealed two strategies of tiger predation. Since the distribution of resources within an individual home range affect the survival and reproduction of the predator, the study is of great importance not only for a more detailed understanding of the relationship in the tigerprey system, but also for the conservation of Amur tiger.

Fatty acid methyl esters (biodiesel), prepared from transesterification of vegetable oils or animal fats, have gained great importance in substituting petroleum based diesel for combating environmental problems and higher diesel prices. Moringa oleifera fatty acids are among the newly investigated potentials for biodiesel production in recent years. In getting rid of soap formation and thus large waste washing water from biodiesel produced from homogenous catalysts, the use of heterogeneous catalysts is currently preferred due to easily separation and purification of the final products. In this study, biodiesel was produced from moringa oleifera oil using sulfated tin oxide enhanced with SiO2 (SO42−/SnO2−SiO2) as super acid solid catalyst. The experimental design was done using design of experiment (DoE), specifically, response surface methodology based on three-variable central composite design (CCD) with alpha (α) = 2. The reaction parameters in the optimization process were reaction temperature (60°C to 180°C), reaction period (1 to 3 hrs) and methanol to oil ratio (1:6 to 1:24 mol/mol). It was observed that the yield up to 84wt% of moringa oleifera methyl esters can be obtained with reaction conditions of 150°C temperature, 150 minutes reaction time and 1:19.5 methanol to oil ratio, while catalyst concentration and agitation speed are kept at 3wt% and 350 rpm respectively.