No abstract

Most endangered species exist today in small populations, many of which are isolated. Evolution in such populations is largely governed by genetic drift. Empirical evidence for drift affecting striking phenotypes based on substantial genetic data are rare. Approximately 37% of tigers (Panthera tigris) in the Similipal Tiger Reserve (in eastern India) are pseudomelanistic, characterized by wide, merged stripes. Camera trap data across the tiger range revealed the presence of pseudomelanistic tigers only in Similipal. We investigated the genetic basis for pseudomelanism and examined the role of drift in driving this phenotype's frequency. Whole-genome data and pedigree-based association analyses from captive tigers revealed that pseudomelanism cosegregates with a conserved and functionally important coding alteration in Transmembrane Aminopeptidase Q (Taqpep), a gene responsible for similar traits in other felid species. Noninvasive sampling of tigers revealed a high frequency of the Taqpep p.H454Y mutation in Similipal (12 individuals, allele frequency = 0.58) and absence from all other tiger populations (395 individuals). Population genetic analyses confirmed few (minimal number) tigers in Similipal, and its genetic isolation, with poor geneflow. Pairwise FST (0.33) at the mutation site was high but not an outlier. Similipal tigers had low diversity at 81 single nucleotide polymorphisms (mean heterozygosity = 0.28, SD = 0.27). Simulations were consistent with founding events and drift as possible drivers for the observed stark difference of allele frequency. Our results highlight the role of stochastic processes in the evolution of rare phenotypes. We highlight an unusual evolutionary trajectory in a small and isolated population of an endangered species.

India led the global tiger conservation initiatives since last decade and has doubled its wild tiger population to 2967 (2603-3346). The survival of these growing populations residing inside the continuously shrinking habitats is a major concern, which can only be tackled through focused landscape-scale conservation planning across five major extant Indian tiger landscapes. The Terai-Arc landscape (TAL) is one of the 'global priority' tiger conservation landscapes holding 22% of the country's wild tigers. We used intensive field-sampling, genetic analyses and GIS modelling to investigate tiger population structure, source-sink dynamics and functionality of the existing corridors across TAL. Genetic analyses with 219 tigers revealed three low, but sigficantly differentiated tiger subpopulations. Overall, we identified Seven source and 10 sink areas in TAL through genetic migrant and gene flow analyses. GIS modelling identified total 19 (10 high, three medium and six low conductance) corridors in this landscape, with 10 being critical to maintain landscape connectivity. We suggest urgent management attention towards 2707 sq. km. non-protected habitat, mitigation measures associated with ongoing linear infrastructure developments and transboundary coordination with Nepal to ensure habitat and genetic connectivity and long-term sustainability of tigers in this globally important landscape.

24Faecal samples have become important non-invasive source of information in wildlife 25 biology and ecological research. Despite regular use of faeces, there is no universal protocol 26 available for faeces collection and storage to answer various questions in wildlife biology. 27 We collected 1408 faeces from ten different species using a dry sampling approach, and 28 achieved 94.87% and 86.02% success rate in mitochondrial and nuclear marker 29 amplifications. We also suggest a universal framework to use the same samples for different 30 use. This protocol provides an easy, quick and cheap option to collect non-invasive samples 31 from species living at different environmental conditions to answer multidisciplinary 32 questions in wildlife biology. 33 34 35 Keywords: Non-invasive wildlife research, species biology, dry sampling, variable habitat, 36 field logistics. 37 38 39 40 41 42 43 44 45 46 Non-invasive samples, in particular faeces have become a regular choice in wildlife biology, 47 population monitoring and ecological research globally. Advantages of faecal sample-based 48 wildlife research include easy sample collection, access to large sample size and spatio-49 temporal coverage. Historically, large scale use of faeces in wildlife biology started with 50 dietary analysis of animals 1 but the introduction of advanced molecular tools added a new 51 dimension to non-invasive research. These molecular tools have allowed biologists to 52 investigate questions regarding population genetics 2,3 , species distribution 4 , demography 5,6 , 53 evolutionary biology 7 and wildlife forensics 8 . In more recent time, faecal samples have been 54 used in addressing various questions related to wildlife physiology including endocrinology 55 and reproductive capacity 9,10 , along with parasitology 11,12 , disease dynamics 13 and 56 conservation genomics 14 . The sampling and storage demands of various questions in non-57 invasive wildlife research have led to a gradual development of faecal sampling and storage 58 protocols. A number of logistical factors including collector's safety, storage in the field, 59 shipping samples from remote field areas with different environmental conditions etc. have 60 been considered while gradual development of these protocols. 61Over the years, a number of faeces collection and storage approaches has been used in 62 wildlife research that are broadly classified into three categories: a) dry sampling (for 63 example simple drying 15 , silica preservation 16 ); b) wet sampling (ethanol collection 17 ; TNE 64 and DMSO buffer 18 ; DETs solution 19 ; RNA later 20 ) and c) two-step approach 21 (see Table 65 1 for details). While all of these approaches have been used in wildlife research, they have 66 several logistical limitations making their implementation in the field challenging. For 67 example, sampling with silica beads has advantages in post-collection sample transport and 68 storage 22 but is not cost effective as it requires large amount of silica beads to keep samples 6...

India led the global tiger conservation initiatives since last decade and has doubled its wild tiger population to 2967 (2603-3346). The survival of these growing populations residing inside the continuously shrinking habitats is a major concern, which can only be tackled through focused landscape-scale conservation planning across five major extant Indian tiger landscapes. The Terai-Arc landscape (TAL) is one of the global priority tiger conservation landscapes holding 22% of the countrys wild tigers. We used intensive field-sampling, genetic analyses and GIS modelling to investigate tiger population structure, source-sink dynamics and functionality of the existing corridors across TAL. Genetic analyses with 219 tigers revealed three low, but significantly differentiated tiger subpopulations. Overall, we identified Seven source and 10 sink areas in TAL through genetic migrant and gene flow analyses. GIS modelling identified total 19 (10 high, three medium and six low conductance) corridors in this landscape, with 10 being critical to maintain landscape connectivity. We suggest urgent management attention towards 2707 sq. km. non-protected habitat, mitigation measures associated with ongoing linear infrastructure developments and transboundary coordination with Nepal to ensure habitat and genetic connectivity and long-term sustainability of tigers in this globally important landscape.