@article {145429, title = {On the road to losing connectivity: Faecal samples provide genome-wide insights into anthropogenic impacts on two large herbivore species in central India.}, journal = {Mol Ecol}, year = {2024}, month = {2024 Jul 03}, pages = {e17461}, abstract = {

Humans have impacted most of the planet, and the ensuing fragmentation results in small, isolated habitat patches posing a risk of genetic diversity loss, inbreeding, and genetic load. Understanding how natural and anthropogenic landscape features affect gene flow among habitat patches is critical for maintaining connectivity. Genome-wide data are required to comprehend the impacts of recent fragmentation, which can be challenging when only non-invasive samples are available. Here, we build upon advancements in conservation genomics to address connectivity of two large herbivores, gaur (Bos gaurus) and sambar (Rusa unicolor) in central India. Given their habitat associations, we expected these species to respond similarly to habitat fragmentation. We used faecal-DNA and methylation-based host-DNA enrichment with modified ddRAD protocol to generate genome-wide single-nucleotide polymorphism (SNP) data for 124 gaur and 99 sambar individuals. Our findings reveal that gaur populations in central India are fragmented, displaying high genetic differentiation, with drift significantly affecting small populations like Umred Karhandla Wildlife Sanctuary. Although sambar shows low genetic structure, another small population, Bor Tiger Reserve is genetically differentiated. Our results suggest that although land cover change and roads restrict animal movement, the extent of this impact varies across the two species. We show that different species respond differently to landscape features, even with similar habitat associations. We highlight small and isolated populations requiring urgent conservation intervention. Such multi-species approaches enhance our understanding of cross-species connectivity patterns. We suggest shifting from single-species to multi-species holistic conservation approach in rapidly developing landscapes to better manage co-occurring endangered species.

}, issn = {1365-294X}, doi = {10.1111/mec.17461}, author = {Tyagi, Abhinav and Yadav, Nidhi and Pandit, Awadhesh and Ramakrishnan, Uma} } @article {129159, title = {Citizen science facilitates first ever genetic detection of wolf-dog hybridization in Indian savannahs.}, journal = {Ecol Evol}, volume = {13}, year = {2023}, month = {2023 May}, pages = {e10100}, abstract = {

Human demographic expansion has confined wildlife to fragmented habitats, often in proximity to human-modified landscapes. Such interfaces facilitate increased interactions between feral or domesticated animals and wildlife, posing a high risk to wild species. This is especially relevant for free-ranging dogs () and wild canids like gray wolves () and golden jackals (). Wolf-dog hybridization may lead to a significant reduction of specific adaptations in wolves that could result in the decline of wolf populations. Detection and genetic discrimination of hybrids between dogs and wolves are challenging because of their complex demographic history and close ancestry. Citizen scientists identified two phenotypically different-looking individuals and subsequently collected non-invasive samples that were used by geneticists to test wolf-dog hybridization. Genomic data from shed hair samples of suspected hybrid individuals using double-digest restriction-site-associated DNA (ddRAD) sequencing resulted in 698 single nucleotide polymorphism (SNP) markers. We investigated the genetic origin of these two individuals analyzed with genetically known dogs, wolves, and other canid species including jackals and dholes (). Our results provide the first genetic evidence of one F2 hybrid and the other individual could be a complex hybrid between dogs and wolves. Our results re-iterate the power of next-generation sequencing (NGS) for non-invasive samples as an efficient tool for detecting hybrids. Our results suggest the need for more robust monitoring of wolf populations and highlight the tremendous potential for collaborative approaches between citizens and conservation scientists to detect and monitor threats to biodiversity.

}, issn = {2045-7758}, doi = {10.1002/ece3.10100}, author = {Tyagi, Abhinav and Godbole, Mihir and Vanak, Abi Tamim and Ramakrishnan, Uma} } @article {95761, title = {Considerations for Initiating a Wildlife Genomics Research Project in South and South-East Asia}, journal = {JOURNAL OF THE INDIAN INSTITUTE OF SCIENCE}, year = {2021}, month = {07/2021}, abstract = {

Next-generation sequencing (NGS) based genomic studies are revolutionizing the field of wildlife biology. These methods have yielded unprecedented insights for understanding ecology, evolution and conservation of wild populations. Despite the advantages, biodiversity rich regions in the tropics need more NGS-based studies to understand their native species. However, the field has progressed very slowly in these regions due to several challenges, including that most experts in the field are not based here. In this article, we highlight the factors that need to be considered before initiating a wildlife genomics research project with a focus on south and south-east Asia, though several factors apply to other regions as well. We highlight the challenges like policy issues for collecting samples and need for better sequencing and computational infrastructure. Finally, we discuss how global initiatives can help such regions setup NGS-based studies of wildlife.

}, doi = {10.1007/s41745-021-00243-3}, author = {Khan, Anubhab and Tyagi, Abhinav} } @article {95517, title = {Trends in Wildlife Connectivity Science from the Biodiverse and Human-Dominated South Asia}, journal = {JOURNAL OF THE INDIAN INSTITUTE OF SCIENCE}, year = {2021}, month = {06/2021}, abstract = {

The threat of habitat fragmentation and population isolation looms large over much of biodiversity in this human-dominated epoch. Species-rich South Asia is made particularly vulnerable by its high human density and anthropogenic habitat modification. Therefore, reliably estimating wildlife connectivity and the factors underpinning it become crucial in mitigating extinction risk due to isolation. We analysed peer-reviewed literature on connectivity and corridors for terrestrial mammals in South Asia to identify trends in connectivity research. We identify key research gaps and highlight future directions that may aid efforts to robustly study connectivity. We found a significant bias towards charismatic megafauna and their habitats. Methodologically, although we observed a range of approaches reflecting some of the advances and innovations in the field, several studies lacked data on animal movement/behaviour, leading to potentially biased inferences of how species disperse through human-modified landscapes. New avenues for connectivity research, though currently under-explored in South Asia, offer alternatives to the heavily used but less-reliable habitat suitability models. We highlight the advantages of landscape genetic methods that reflect effective dispersal and are made feasible through non-invasive and increasingly more cost-effective sampling methods. We also identify important gaps or areas of focus that need to be addressed going forward, including accounting for animal movement/behaviour, human impacts and landscape change for dynamic and adaptive connectivity planning for the future.

}, doi = {10.1007/s41745-021-00240-6}, author = {Thatte, Prachi and Tyagi, Abhinav and Neelakantan, Amrita and Natesh, Meghana and Sen, Mihika and Thekaekara, Tarsh} }