Green Minute News:

India’s first ever population estimates of the endangered dhole (or Asiatic wild dog) has been carried out by scientists using genetic information and advanced population models.

Scientists have recommended that methods developed and demonstrated in the study should be used as a “standard protocol” for estimating dhole numbers and for conservation monitoring of their population in other Protected Areas of the country and also across the dholes’ distribution range.

In a new study, scientists from Wildlife Conservation Society (WCS), India, National Centre for Biological Sciences (NCBS), Bengaluru, Kerala Veterinary and Animal Sciences University, University of Florida and Stanford University have developed a scientifically robust method to estimate dhole numbers for the first time. The dhole is one such carnivorous species that is endangered even as their population numbers remain unknown. Until now, there were no methods available to reliably estimate dhole populations. 

In 2019, scientists conducted field surveys across 350 square kilometres of Wayanad Wildlife Sanctuary to collect dhole scats. They extracted DNA from the scats and used a novel approach involving Single Nucleotide Polymorphisms to identify unique individuals. Combining this with sophisticated statistical methods called Spatial Capture-Recapture models, the researchers were able to estimate and map dhole numbers and density across this sanctuary. 

The study found that Wayanad has 12-14 dholes per 100 sq km with around 50 individuals estimated within the sanctuary’s boundary. Arjun Srivathsa, WCS and lead author of the study said, “Ours is the first attempt to estimate dhole populations through targeted surveys designed specifically for this species. The results suggest that Wayanad supports high densities of the dhole. Recent tiger surveys have shown the sanctuary also has a relatively large tiger population with 11-13 animals per 100 sq km. The fact that two large carnivores can co-exist in such high densities is indicative of an abundant prey base and high-quality habitat.” 

According to Co-author Uma Ramakrishnan, NCBS, “For species like dholes that do not have individual markings, genetic methods are the only way we can get statistically robust estimates of population size. The cutting-edge genetic tools we developed here to understand more about this endangered species will be critical for evidence-based conservation of dholes.” 

The study titled, “The truth about scats and dogs: Next-generation sequencing and spatial capture-recapture models offer opportunities for conservation monitoring of an endangered social canid” was recently published in the international journal Biological Conservation. The authors include Arjun Srivathsa (WCS, India and University of Florida), Co-lead Ryan G. Rodrigues (WCS, India and NCBS), Kok Ben Toh (University of Florida), Dr Arun Zachariah (Kerala Veterinary and Animal Sciences University), Ryan W. Taylor (Stanford University), Madan K. Oli (University of Florida) and Prof. Uma Ramakrishnan (NCBS).