New Ecological Study Generates Methods And Results To Save Tropical Forest Ungulates

We are pleased to announce the publication of a new Scientific Monograph titled ‘Spatial Dynamics and Ecology of Large Ungulate Populations in Tropical Forests of India’ by CWS scientists and collaborators and published by Springer Nature. The publication is based on field work and analyses conducted on population ecology of five species of threatened ungulates: Gaur, Sambar, Chital, Muntjac and Wild Pig in the -Nagarahole- Bandipur protected landscape.

The study involved the conduct of line transect surveys on foot, designed and implemented advanced distance sampling methods. The data generated were analyzed using spatially explicit hierarchical distance sampling models, one of the first studies in the world employing these advanced methods.

The study rigorously estimated population densities of these five ungulates at both local and landscape scales, and explored causal factors underlying the variations in their densities in terms of different ecological and management factors.

The results showed that population densities of focal species locally varied between 0.2 and 5.1 /km2

for gaur, 0.5 and 8.1 / km2

for sambar, 0.9 and 39.8 / km2

for chital, 0.1 and 0.7 / km2

for muntjac

and, 0.1 and 1.1 / km2

for wild pig, in response to varying environmental factors..The analytic methodology of Bayesian Hierarchical modeling used by the authors, generated more rigorous and nuanced results useful for conservation, without involving any additional investment of resources compared to standard line transect sampling.

Quote 1 - Samba Kumar: “Our results have both scientific and management implications. These are the first population ecology data and results gathered at such fine-grained scales on these vulnerable species which are under threat across their range in Asia. The study also highlights the importance of strict anti-hunting measures and regulation of human impacts on habitats, which are far more important to recover these species than many of the expensive commonly employed habitat management practices. Our study also provides a scientifically robust decision-making framework to prioritize management actions to accomplish conservation goals”.

Quote 2 - Ullas Karanth: “The approaches we developed and the results we generated have wide application for surveying large ungulate populations all over the world. In view of the fact that almost all the putative line transect surveys now being conducted across Asia, including those in India, lack rigor and generate unreliable results, there is ample scope for adopting our methods in the future. Because tropical forest ungulates are under serious threat, I hope such adoption will be prioritized by the Government.”

Quote 3 - James Nichols: "With a few notable exceptions, our knowledge of the population ecology of large, mobile animals is very limited, primarily because of the difficulty of studying such animals at relevant spatial scales. The study reported in this book is exceptional in being well-planned, well-executed via an enormous, supervised field effort, and well-analyzed using state-of-the-art data-analytic approaches. As a result, the study provides strong inferences about the spatial ecology and conservation of the focal ungulates and provides a model for the large-scale study of mobile animal populations."

The scientific monograph titled, Spatial Dynamics and Ecology of Large Ungulate Populations in Tropical Forests of India’ is authored by N Samba Kumar, K. Ullas Karanth (Centre for Wildlife Studies (CWS), Bengaluru), James D Nichols (University of Florida, USA), Srinivas Vaidyanathan (Foundation for Ecological Research, Advocacy and Learning, Pondicherry), Beth Gardner ( University of Washington, USA) and Jagdish Krishnaswamy (Ashoka Trust for Research in Ecology and the Environment).