Primates, Ungulates and other Large Mammals
The lion-tailed macaque found in the Western Ghats section of Kerala and Karnataka is showing very low growth rates. Given the difficulty of monitoring this species, earlier surveys involved researchers walking along trails and counting groups. The WCS-India team, along with the Kerala Forest Department, is conducting a threat assessment survey for the mammal in the Silent Valley National Park and studying ways to monitor them better.
Apart from socio-political issues of the region, other challenges include the low density of the macaque population, and the fact that tree cover does not allow for proper sighting of these animals. The team has conducted questionnaire surveys to determine popular sentiment on conservation and related issues.
The Indian sub-continent supports a wide variety of other ungulates, some with large distributional ranges and others restricted to a few small populations. Cervids such as sambar (Rusa unicolor), chital (Axis axis), muntjac (Muntiacus vaginalis) and Indian chevrotain (Moschiola meminna) are widespread and found in a wide variety of habitats across India. Bovids include antelopes such as the chowsingha (Tetracerus quadricornis), chinkara (Gazella bennettii) and the blackbuck (Antilope cervicapra), while suids are represented by wild pig (Sus scrofa) and pygmy hog (Sus salvanius).
Our work on ungulates in India includes pioneering advances in the development and refinement of techniques to estimate population parameters of forest ungulates (including field and analytical protocols for distance sampling-based density estimation in forests), density estimation using occurrence data and the development of hierarchical modelling approaches to assess factors determining ungulate densities and distribution. The resulting estimates of population parameters from these field studies have also supported large-scale and long-term monitoring of ungulate populations, assessments of how large carnivores select prey depending on the availability of different species, investigations of how ungulate densities determine tiger densities, and other such questions with immediate applications to the conservation and monitoring of ungulates in India.
Through courses, workshops and technical manuals, we have widely disseminated our findings to enable conservation scientists worldwide to reliably estimate population parameters.
Megaherbivores populations are largely free of top-down control by predation and thus play critical roles in tropical ecosystems. Indian forest and grassland ecosystems support high densities and large population sizes of three such megaherbivores: Asian elephant (Elephas maximus), Indian one-horned rhinoceros (Rhinoceros unicornis) and gaur (Bos frontalis). Our work has largely focussed on the estimation of ecological densities and biomass, and various methodological issues related to monitoring populations of these species in India, producing some of the first benchmark estimates in southern, central and eastern India.