More than a decade has passed since the catastrophic population decline in Gyps species was reported from South Asia, but much uncertainty remains about quantifying their short-term extinction risk. To estimate the future extinction risk of the white-rumped vulture Gyps bengalensis in Nepal, we conducted counts at 7 nesting colonies between 2002 and 2012. We compared 3 methods of estimating abundance based on count data and calculated mean population growth rates and cumulative probabilities of extinction given the abundance estimates from each method. The first 2 methods of abundance estimation were traditional indices: mean and maximum values of all counts. The third method was a mixture modeling approach that corrected raw counts by a detection parameter. The results of the traditional indices were characterized by high uncertainty levels as reflected in the wide confidence intervals, which limited their capacity to make predictions about the fate of the populations with any confidence. The mixture modeling method provided more reliable results; there was a 51% probability of populations facing quasiextinction (i.e. ≤20 vultures) in 13 yr and a 99% probability of quasi-extinction in 18 yr. Because the mixture modeling method provided more precise predictions while requiring minimal additional effort, population biologists using count data are encouraged to employ such model-based estimators. The white-rumped vulture populations in Rampur are in danger of disappearing within 2 decades, so conservation efforts should be expedited to prevent the loss of this species.
Urbanization can have profound consequences for mammalian biodiversity and is thought to contribute to patterns of species richness and community composition. Large cities can be particularly challenging environments for mammals because these habitats are often impacted by anthropogenic perturbations, including high human population density, fragmented habitats, and extensive human development. In this study, we investigated mammalian species richness, Shannon–Wiener diversity, and evenness in the most densely populated region in the United States: the New York metropolitan area. Specifically, we deployed camera traps from 2015 to 2019 to investigate six drivers of mammalian diversity across 31 greenspaces: (1) human population density, (2) patch size, (3) habitat type, (4) surrounding land cover, (5) geographical barriers to dispersal, and (6) habitat heterogeneity. We found that mammal community composition is largely influenced by a multitude of anthropogenic factors. Specifically, mammal species richness was higher in greenspaces with larger patch sizes and lower in greenspaces surrounded by more development. Moreover, Shannon–Wiener diversity and evenness were higher in urban natural landscapes than human-altered landscapes. In a subset of data that only included carnivores, we found that carnivore Shannon–Wiener diversity was higher in urban natural habitats and in sites with lower human population densities. Finally, we found that geographical barriers to dispersal contributed to both patterns of mammalian diversity and patterns of carnivore diversity: mammal taxa richness, Shannon–Wiener diversity, and evenness were all significantly higher on the continent (Bronx/Westchester) than on Long Island. These results suggest that preserving urban greenspaces is important for maintaining both mammalian and carnivore biodiversity and that management of mammals in cities should concentrate on maintaining large, connected, natural greenspaces.
Coyotes are ubiquitous on the North American landscape as a result of their recent expansion across the continent. They have been documented in the heart of some of the most urbanized cities, such as Chicago, Los Angeles, and New York City. Here, we explored the genomic composition of coyotes in the New York metropolitan area to investigate if genomic demography and admixture differs from expected for urban-dwelling canids. We identified moderate-to-high estimates of relatedness among coyotes living in Queens and adjacent neighborhoods, suggestive of a relatively small population. Although we found low background levels of domestic dog ancestry across most coyotes in our sample, we identified a male suspected to be a first-generation coyote-dog hybrid, as well as his two putative backcrossed offspring that carried approximately 25% dog ancestry. The male coyote-dog hybrid and one backcrossed offspring each carried two mutations that are known to increase human-directed hypersociability in dogs and gray wolves. An additional, unrelated coyote with little dog ancestry also carries two of these mutations. These genetic patterns suggest that gene flow from domestic dogs may become an increasingly important consideration as coyotes continue to inhabit metropolitan regions.
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