Genetic Evidence of Tiger Population Structure and Migration within an Isolated and Fragmented Landscape in Northwest India

Abstract

BackgroundMajority of the tiger habitat in Indian subcontinent lies within high human density landscapes and is highly sensitive to surrounding pressures. These forests are unable to sustain healthy tiger populations within a tiger-hostile matrix, despite considerable conservation efforts. Ranthambore Tiger Reserve (RTR) in Northwest India is one such isolated forest which is rapidly losing its links with other tiger territories in the Central Indian landscape. Non-invasive genetic sampling for individual identification is a potent technique to understand the relationships between threatened tiger populations in degraded habitats. This study is an attempt to establish tiger movement across a fragmented landscape between RTR and its neighboring forests, Kuno-Palpur Wildlife Sanctuary (KPWLS) and Madhav National Park (MNP) based on non-invasively obtained genetic data.MethodsData from twelve microsatellite loci was used to define population structure and also to identify first generation migrants and admixed individuals in the above forests.ResultsPopulation structure was consistent with the Central Indian landscape and we could determine significant gene flow between RTR and MNP. We could identify individuals of admixed ancestry in both these forests, as well as first generation migrants from RTR to KPWLS and MNP.ConclusionsOur results indicate reproductive mixing between animals of RTR and MNP in the recent past and migration of animals even today, despite fragmentation and poaching risk, from RTR towards MNP. Substantial conservation efforts should be made to maintain connectivity between these two subpopulations and also higher protection status should be conferred on Madhav National Park.

A comparative study of the use of tiger-specific and heterologous microsatellite markers for population genetic studies of the Bengal tiger (Panthera tigris tigris)

“…The number of alleles per locus at the polymorphic loci (n = 16) ranged from three to five (average 3.625), the effective number of alleles per locus ranged from 2.000 to 3.447 (average 2.781), and the mean PIC was 0.575 (Table 2). Considering the small number of individuals in our study, we support our results by examining the mean values of H E and H O (0.675 and 0.668, respectively) of the combined panel (n=16), which are comparable with the reported mean values of H E (0.655 to 0.810) and H O (0.650 to 0.7624) in non-invasive genetic studies carried out on the Bengal tiger (Reddy et al, 2012;Gour et al, 2013;Sharma et al, 2013). We established the relatedness among the captive tigers (n = 8) using the combined panel of highly polymorphic loci and estimated the mean value of the relatedness coefficient (R = -0.143), which indicated that the selected tigers were not highly related to each other, as is mostly expected in captive individuals.…”

Fine-scale population genetic structure of the Bengal tiger (Panthera tigris tigris) in a human-dominated western Terai Arc Landscape, India

“…However, most genetic studies conducted on the Bengal tiger have been either in some way focused on the global status [41, 42] or were carried out in different tiger landscapes or regions, such as the Central and Peninsular [43, 44], Western (e.g. Ranthambhore Tiger Reserve) [45] and Sundarbans [46]. Despite the current knowledge of the tiger’s ecology, there is no information on the gene flow and genetic structure of the tiger population especially in WTAL, which holds the largest number of tigers [32], except from mitochondrial (mtDNA) markers [47,48].…”

Recent Geological Events and Intrinsic Behavior Influence the Population Genetic Structure of the Chiru and Tibetan Gazelle on the Tibetan Plateau

“…The uplift of the Qinghai-Tibetan Plateau and the associated or contemporaneous climate changes are widely regarded as the most important factors influencing current spatial distribution of local species and their genetic diversity on the plateau [14], [15]. In addition to the well-documented observation that population genetic structure is usually shaped by geographic and environmental factors [16], [17], some species-intrinsic behaviors and life history traits, for example, migration, dispersal and mating, can also affect the population genetic structure and recent evolutionary history of species [18]–[22].…”