Disease outbreaks and pathogen introductions can have significant effects on host populations, and the ability of pathogens to persist in the environment can exacerbate disease impacts by fueling sustained transmission, seasonal epidemics, and repeated spillover events. While theory suggests that the presence of an environmental reservoir increases the risk of host declines and threat of extinction, the influence of reservoir dynamics on transmission and population impacts remains poorly described. Here we show that the extent of the environmental reservoir explains broad patterns of host infection and the severity of disease impacts of a virulent pathogen. We examined reservoir and host infection dynamics and the resulting impacts of Pseudogymnoascus destructans, the fungal pathogen that causes white-nose syndrome, in 39 species of bats at 101 sites across the globe. Lower levels of pathogen in the environment consistently corresponded to delayed infection of hosts, fewer and less severe infections, and reduced population impacts. In contrast, an extensive and persistent environmental reservoir led to early and widespread infections and severe population declines. These results suggest that continental differences in the persistence or decay of P. destructans in the environment altered infection patterns in bats and influenced whether host populations were stable or experienced severe declines from this disease. Quantifying the impact of the environmental reservoir on disease dynamics can provide specific targets for reducing pathogen levels in the environment to prevent or control future epidemics.

Globalization has facilitated the worldwide movement and introduction of pathogens, but epizoological reconstructions of these invasions are often hindered by limited sampling and insufficient genetic resolution among isolates. Pseudogymnoascus destructans, a fungal pathogen causing the epizootic of white-nose syndrome in North American bats, has exhibited few genetic polymorphisms in previous studies, presenting challenges for both epizoological tracking of the spread of this fungus and for determining its evolutionary history. We used single nucleotide polymorphisms (SNPs) from whole-genome sequencing and microsatellites to construct high-resolution phylogenies of P. destructans. Shallow genetic diversity and the lack of geographic structuring among North American isolates support a recent introduction followed by expansion via clonal reproduction across the epizootic zone. Moreover, the genetic relationships of isolates within North America suggest widespread mixing and long-distance movement of the fungus. Genetic diversity among isolates of P. destructans from Europe was substantially higher than in those from North America. However, genetic distance between the North American isolates and any given European isolate was similar to the distance between the individual European isolates. In contrast, the isolates we examined from Asia were highly divergent from both European and North American isolates. Although the definitive source for introduction of the North American population has not been conclusively identified, our data support the origin of the North American invasion by P. destructans from Europe rather than Asia.

1. Conservation of nomadic species presents significant conservation challenges because of unpredictability in their movements and space use. Long-term studies on nomadic species offering insights into the variability in space use within and between years are largely missing but are necessary to develop effective conservation strategies.2. We examined the temporal variability in space-use of Mongolian gazelle, a nomadic species. We tracked 22 individuals for 1-3 years with GPS and used the resulting movement patterns to evaluate conservation strategies associated with their nomadic movements in the intact open plain grasslands of Mongolia.Individuals exhibited a high degree of variability in space use within and between years, often using different wintering areas in different years. The individual range size varied as much as threefold between years, with an estimated average annual individual range size of ~19,000 km 2 and a lifetime range of ~100,000 km 2 . Comparing simulated and empirical GPS trajectories for the Mongolian gazelleshowed that they avoided disturbed areas (e.g. oil fields) and did not prefer protected areas. Importantly, no single protected area in the region was large enough to cover the annual range of any of the tracked gazelle.4. Because of their wide-ranging movements, the presence of linear infrastructure and the resulting barrier effects are a particular concern. We found that fences along the national border were absolute barriers affecting movements of about 80% of all tracked individuals. When gazelle encounter the border fence, they moved a median distance of 11 km along fences, suggesting frequent crossing options are needed to make barriers permeable.

Around the world, climate change has impacted many species. In this study, we used bioclimatic variables and biophysical layers of Central Asia and the Asian Highlands combined with presence data of brown bear (Ursus arctos) to understand their current distribution and predict their future distribution under the current rate of climate change. Our bioclimatic model showed that the current suitable habitat of brown bear encompasses 3,430,493 km2 in the study area, the majority of which (>65%) located in China. Our analyses demonstrated that suitable habitat will be reduced by 11% (378,861.30 km2) across Central Asia and the Asian Highlands by 2,050 due to climate change, predominantly (>90%) due to the changes in temperature and precipitation. The spatially averaged mean annual temperature of brown bear habitat is currently −1.2°C and predicted to increase to 1.6°C by 2,050. Mean annual precipitation in brown bear habitats is predicted to increase by 13% (from 406 to 459 mm) by 2,050. Such changes in two critical climatic variables may significantly affect the brown bear distribution, ethological repertoires, and physiological processes, which may increase their risk of extirpation in some areas. Approximately 32% (1,124,330 km2) of the total suitable habitat falls within protected areas, which was predicted to reduce to 1,103,912 km2 (1.8% loss) by 2,050. Future loss of suitable habitats inside the protected areas may force brown bears to move outside the protected areas thereby increasing their risk of mortality. Therefore, more protected areas should be established in the suitable brown bear habitats in future to sustain populations in this region. Furthermore, development of corridors is needed to connect habitats between protected areas of different countries in Central Asia. Such practices will facilitate climate migration and connectivity among populations and movement between and within countries.

Studies of the distribution, assessment of the Snow leopard population, as well as the state of the populations of its main prey species, the impact of anthropogenic factors are the basis for the development of long-term and effective action plans and strategies for its conservation. To this end, we have carried out work on three different territories of the Mongolian Altai: Jargalant, Bumbat and Baatar Khairkhan Mountains. All three territories differ in the nature of the location in relation to other parts of the Snow leopard's range, and in the nature of the relief and economic use. The main method of research is the search and registration of traces of life activity of the Snow leopard and its main prey species (Mongolian marmot and Siberian ibex). For this purpose, we have passed 18 research routes with a total length of 197.5 km where we recorded all traces of the Snow leopard, Siberian ibex and Mongolian marmot life activities, as well as the distribution of the number of livestock. Another research method we have used is the application of camera traps. We installed 27 camera traps in total. As a result of their work we have obtained 51 photo location of the Snow leopard and identified at least 3 females, 2-3 adult males, 2-3 young individuals, the sex of which could not be established, including individuals aged about 2 years, 2 cubs. Both methods of research (search for traces of life activities and the application of camera traps) complement each other, and the correct use of camera traps can reduce the subjectivity of the results obtained by the search for traces of life activities. Thus, the reliability of the results is significantly increased. Our studies show that the largest number of traces of Snow leopard activity (the number of scrapes per 1 km of the route) and the largest number of photo locations were recorded in the central part of the Jargalant khairkhan mountain range-the territory that is the most remote and inaccessible for grazing livestock. In this territory, the highest frequency of Snow leopard presence was noted (20-40 scratches/km), and accordingly 5 from 11 identified snow leopards were registered. A similar pattern of distribution of traces of vital activity was registered for the other two territories.