Tigers in the Terai: Strong evidence for meta-population dynamics contributing to tiger recovery and conservation in the Terai Arc Landscape

Abstract

The source populations of tigers are mostly confined to protected areas, which are now becoming isolated. A landscape scale conservation strategy should strive to facilitate dispersal and survival of dispersing tigers by managing habitat corridors that enable tigers to traverse the matrix with minimal conflict. We present evidence for tiger dispersal along transboundary protected areas complexes in the Terai Arc Landscape, a priority tiger landscape in Nepal and India, by comparing camera trap data, and through population models applied to the long term camera trap data sets. The former showed that 11 individual tigers used the corridors that connected the transboundary protected areas. The estimated population growth rates using the minimum observed population size in two protected areas in Nepal, Bardia National Park and Suklaphanta National Park showed that the increases were higher than expected from growth rates due to in situ reproduction alone. These lines of evidence suggests that tigers are recolonizing Nepal’s protected areas from India, after a period of population decline, and that the tiger populations in the transboundary protected areas complexes may be maintained as meta-population. Our results demonstrate the importance of adopting a landscape-scale approach to tiger conservation, especially to improve population recovery and long term population persistence.

Assessing the adequacy of a protected area network in conserving a wide‐ranging apex predator: The case for tiger (Panthera tigris) conservation in Bhutan

“…Because of its status as a national priority species (Wang & Macdonald, 2009), landscape-level tiger studies in Bhutan have mainly focused on population (Tempa, Hebblewhite, Goldberg, et al, 2019;Thinley, Dorji, Tempa, et al, 2015) and movement dynamics (Thinley et al, 2020), as conducted elsewhere in South India (Gubbi et al, 2016), China (Wang et al, 2018), and the Terai Arc Landscape straddling Nepal and India (Thapa, Wikramanayake, Malla, et al, 2017). In an effort to maintain viable tiger populations, some studies have additionally prioritized assessment of landscape connectivity through various approaches such as mapping potential forest loss in Sumatra (Poor, Shao, & Kelly, 2019), investigating metapopulation gene flow in central India (Seidensticker, 2016), and spatially identifying corridors in western India (Mondal, Habib, Talukdar, & Nigam, 2016).…”

Assessment of genetic diversity, population structure, and gene flow of tigers (Panthera tigris tigris) across Nepal's Terai Arc Landscape

“…Our main study objectives were to: 1) document the scale and distribution of land use change over the last 300 years in the TAL landscape, 2) determine the number of genetic groups of tigers, 3) assess genetic diversity, population structure and gene flow, 4) determine the level of contemporary migration between genetic groups, and 5) test for evidence of population bottlenecks. We hypothesized that tigers would group into three genetic clusters representing the three demographic tiger populations previously identified in TAL-Nepal [ 34 ]. Given the high degree of land use change in the past, we expected low to moderate levels of genetic diversity; and limited but detectable gene flow within the region.…”

Elephant (Elephas maximus) temporal activity, distribution, and habitat use patterns on the tiger’s forgotten trails across the seasonally dry, subtropical, hilly Churia forests of Nepal

“…Churia habitat is contiguous with the southern buffer zone to form the Madi Valley with a high human population density of 440 per km 2 [8]. Churia habitat forms the main interlinking hill forest block that provides connectivity to Valmiki Tiger Reserve in India, and the Parsa National Park and Chitwan National Park in Nepal, to form a Chitwan-Parsa-Valmiki protected area complex [17].…”