72 research outputs found
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Distribution and Population Dynamics of Ungulates in the Mongolian Gobi
The Mongolian Gobi is one of the most spectacular and important regions in Central Asia, comprising the largest area of intact grassland in the world. In recent years, a growing human population, expanding exploitation of natural resources, and the development of infrastructure in the region place increasing pressure on these species and their habitats. This dissertation has focused on three species of ungulates such as Mongolian saiga (Saiga tatarica mongolica) in western Mongolia, and Asiatic wild ass (Equus hemionus), and goitered gazelle (Gazella subgutturosa) in Southern Gobi. The study on endangered saiga antelope in western Mongolia found that the calving location selection of saiga influenced by multiple factors and individual saiga females preferred calving locations that were away from settlements and closer to water sources and avoided steeper slopes. While the variation in saiga group size predominantly determined by Normalized Difference Vegetation Index, predation rate and season. These results demonstrate that the choice of calving locations and grouping patterns of saiga antelope is driven by both internal and external factors. Understanding which factors influence calving location selection and variation in group size for saiga provides insights to the management of this endangered antelope. The ground-based ungulate survey in the Southern Gobi of Mongolia confirm that Mongolia’s Gobi desert still supports the largest population of khulan and goitered gazelle in the world. Spatial analyses results of the ground survey suggest disturbance associated with human activities have a negative influence on the amount and distribution of suitable habitats for khulan and goitered gazelles in Southern Gobi. Spatially explicit models also indicate approximately half the study area is unsuitable habitat for khulan and goitered gazelles. The data presented here contain valuable information on factors influencing distribution and calving site selection of the plains ungulates and these results can be used to plan mitigation measures and reduce the impacts of developments. The ways in which we approach this important question can also serve as a model for other systems
Capture of Ungulates in Central Asia Using Drive Nets: Advantages and Pitfalls Illustrated by the Endangered Mongolian Saiga Saiga Tatarica Mongolica
The study of mammals suffering intense poaching in remote areas poses an increasingly difficult conservation challenge, in part because the extreme flightiness of such species complicates safe capture. The benefits of handling (an opportunity to obtain biological information and attach radio collars) must be weighed against stress to the animals and potential capture-related mortality. In parts of Central Asia this problem is not trivial, as populations have been heavily harvested and opportunities for restraint are often limited. Mongolian saiga Saiga tatarica mongolica, being both Endangered and poached, typifies these issues. Here we describe capture protocols for adult females handled quickly and without anaesthesia. Using multiple vehicles driven at high speed, individual saiga were isolated from groups and herded into nets. Chase time was linearly associated with rectal temperature (P \u3c 0.03), with maximum pursuits and temperatures of 9 minutes and 43.1 degrees C, respectively; time to release averaged \u3c7 minutes. Given that rural residents often chase saiga and other desert and steppe-dwelling ungulates, for photography or for amusement, our results offer conservationists and government officials an empirical basis for recommending prudence on chase times and/or for recommending that the practice be prevented
Capture of ungulates in Central Asia using drive nets: advantages and pitfalls illustrated by the Endangered Mongolian saiga \u3ci\u3eSaiga tatarica mongolica\u3c/i\u3e
The study of mammals suffering intense poaching in remote areas poses an increasingly difficult conservation challenge, in part because the extreme flightiness of such species complicates safe capture. The benefits of handling (an opportunity to obtain biological information and attach radio collars) must be weighed against stress to the animals and potential capture-related mortality. In parts of Central Asia this problem is not trivial, as populations have been heavily harvested and opportunities for restraint are often limited. Mongolian saiga Saiga tatarica mongolica, being both Endangered and poached, typifies these issues. Here we describe capture protocols for adult females handled quickly and without anaesthesia. Using multiple vehicles driven at high speed, individual saiga were isolated from groups and herded into nets. Chase time was linearly associated with rectal temperature (P,0.03), with maximum pursuits and temperatures of 9 minutes and 43.1 degrees C, respectively; time to release averaged \u3c7 minutes. Given that rural residents often chase saiga and other desert and steppe-dwelling ungulates, for photography or for amusement, our results offer conservationists and government officials an empirical basis for recommending prudence on chase times and/or for recommending that the practice be prevented
Capture of ungulates in Central Asia using drive nets: advantages and pitfalls illustrated by the Endangered Mongolian saiga \u3ci\u3eSaiga tatarica mongolica\u3c/i\u3e
The study of mammals suffering intense poaching in remote areas poses an increasingly difficult conservation challenge, in part because the extreme flightiness of such species complicates safe capture. The benefits of handling (an opportunity to obtain biological information and attach radio collars) must be weighed against stress to the animals and potential capture-related mortality. In parts of Central Asia this problem is not trivial, as populations have been heavily harvested and opportunities for restraint are often limited. Mongolian saiga Saiga tatarica mongolica, being both Endangered and poached, typifies these issues. Here we describe capture protocols for adult females handled quickly and without anaesthesia. Using multiple vehicles driven at high speed, individual saiga were isolated from groups and herded into nets. Chase time was linearly associated with rectal temperature (P,0.03), with maximum pursuits and temperatures of 9 minutes and 43.1 degrees C, respectively; time to release averaged \u3c7 minutes. Given that rural residents often chase saiga and other desert and steppe-dwelling ungulates, for photography or for amusement, our results offer conservationists and government officials an empirical basis for recommending prudence on chase times and/or for recommending that the practice be prevented
Isotope analysis combined with DNA barcoding provide new insights into the dietary niche of khulan in the Mongolian Gobi
With increasing livestock numbers, competition and avoidance are increasingly shaping resource availability for wild ungulates. Shifts in the dietary niche of wild ungulates are likely and can be expected to negatively affect their fitness. The Mongolian Gobi constitutes the largest remaining refuge for several threatened ungulates, but unprecedentedly high livestock numbers are sparking growing concerns over rangeland health and impacts on threatened ungulates like the Asiatic wild ass (khulan). Previous stable isotope analysis of khulan tail hair from the Dzungarian Gobi suggested that they graze in summer but switch to a poorer mixed C3 grass / C4 shrub diet in winter, most likely in reaction to local herders and their livestock. Here we attempt to validate these findings with a different methodology, DNA metabarcoding. Further, we extend the scope of the original study to the South Gobi Region, where we expect higher proportions of low-quality browse in the khulan winter diet due to a higher human and livestock presence. Barcoding confirmed the assumptions behind the seasonal diet change observed in the Dzungarian Gobi isotope data, and new isotope analysis revealed a strong seasonal pattern and higher C4 plant intake in the South Gobi Region, in line with our expectations. However, DNA barcoding revealed C4 domination of winter diet was due to C4 grasses (rather than shrubs) for the South Gobi Region. Slight climatic differences result in regional shifts in the occurrence of C3 and C4 grasses and shrubs, which do not allow for an isotopic separation along the grazer-browser continuum over the entire Gobi. Our findings do not allow us to confirm human impacts upon dietary preferences in khulan as we lack seasonal samples from the South Gobi Region. However, these data provide novel insight into khulan diet, raise new questions about plant availability versuspreference, and provide a cautionary tale about indirect analysis methods if used in isolation or extrapolated to the landscape level. Good concordance between relative read abundance of C4 genera from barcoding and proportion of C4 plants from isotope analysis adds to a growing body of evidence that barcoding is a promising quantitative tool to understand resource partitioning in ungulates.publishedVersio
Longest terrestrial migrations and movements around the world
Long-distance terrestrial migrations are imperiled globally. We determined both round-trip migration distances (straight-line measurements between migratory end points) and total annual movement (sum of the distances between successive relocations over a year) for a suite of large mammals that had potential for long-distance movements to test which species displayed the longest of both. We found that caribou likely do exhibit the longest terrestrial migrations on the planet, but, over the course of a year, gray wolves move the most. Our results were consistent with the trophic-level based hypothesis that predators would move more than their prey. Herbivores in low productivity environments moved more than herbivores in more productive habitats. We also found that larger members of the same guild moved less than smaller members, supporting the 'gastro-centric' hypothesis. A better understanding of migration and movements of large mammals should aid in their conservation by helping delineate conservation area boundaries and determine priority corridors for protection to preserve connectivity. The magnitude of the migrations and movements we documented should also provide guidance on the scale of conservation efforts required and assist conservation planning across agency and even national boundaries
Outbreak of Peste des Petits Ruminants Virus among Criticially Endangered Mongolian Saiga and Other Wild Ungulates, Mongolia, 2016-2017
The 2016–2017 introduction of peste des petits ruminants virus (PPRV) into livestock in Mongolia was followed by mass mortality of the critically endangered Mongolian saiga antelope and other rare wild ungulates. To assess the nature and population effects of this outbreak among wild ungulates, we collected clinical, histopathologic, epidemiologic, and ecological evidence. Molecular characterization confirmed that the causative agent was PPRV lineage IV. The spatiotemporal patterns of cases among wildlife were similar to those among livestock affected by the PPRV outbreak, suggesting spillover of virus from livestock at multiple locations and time points and subsequent spread among wild ungulates. Estimates of saiga abundance suggested a population decline of 80%, raising substantial concerns for the species’ survival. Consideration of the entire ungulate community (wild and domestic) is essential for elucidating the epidemiology of PPRV in Mongolia, addressing the threats to wild ungulate conservation, and achieving global PPRV eradication
Behavioral responses of terrestrial mammals to COVID-19 lockdowns
COVID-19 lockdowns in early 2020 reduced human mobility, providing an opportunity to disentangle its effects on animals from those of landscape modifications. Using GPS data, we compared movements and road avoidance of 2300 terrestrial mammals (43 species) during the lockdowns to the same period in 2019. Individual responses were variable with no change in average movements or road avoidance behavior, likely due to variable lockdown conditions. However, under strict lockdowns 10-day 95th percentile displacements increased by 73%, suggesting increased landscape permeability. Animals' 1-hour 95th percentile displacements declined by 12% and animals were 36% closer to roads in areas of high human footprint, indicating reduced avoidance during lockdowns. Overall, lockdowns rapidly altered some spatial behaviors, highlighting variable but substantial impacts of human mobility on wildlife worldwide.acceptedVersio
Behavioral responses of terrestrial mammals to COVID-19 lockdowns
COVID-19 lockdowns in early 2020 reduced human mobility, providing an opportunity to disentangle its effects on animals from those of landscape modifications. Using GPS data, we compared movements and road avoidance of 2300 terrestrial mammals (43 species) during the lockdowns to the same period in 2019. Individual responses were variable with no change in average movements or road avoidance behavior, likely due to variable lockdown conditions. However, under strict lockdowns 10-day 95th percentile displacements increased by 73%, suggesting increased landscape permeability. Animals' 1-hour 95th percentile displacements declined by 12% and animals were 36% closer to roads in areas of high human footprint, indicating reduced avoidance during lockdowns. Overall, lockdowns rapidly altered some spatial behaviors, highlighting variable but substantial impacts of human mobility on wildlife worldwide.acceptedVersio
Moving in the anthropocene: global reductions in terrestrial mammalian movements
Animal movement is fundamental for ecosystem functioning and species survival, yet the effects of the anthropogenic footprint on animal movements have not been estimated across species. Using a unique GPS-tracking database of 803 individuals across 57 species, we found that movements of mammals in areas with a comparatively high human footprint were on average one-half to one-third the extent of their movements in areas with a low human footprint. We attribute this reduction to behavioral changes of individual animals and to the exclusion of species with long-range movements from areas with higher human impact. Global loss of vagility alters a key ecological trait of animals that affects not only population persistence but also ecosystem processes such as predator-prey interactions, nutrient cycling, and disease transmission
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