Large carnivores across the world face several threats even as they continue to decline in numbers. Understanding where these species occur, how they use their habitats and what factors influence these patterns are important for their conservation. The Asiatic wild dog or dhole (Cuon alpinus) is a unique endangered predator. It is the only social, wild canid that almost exclusively inhabits forest areas in Asia. Historically treated as ‘vermin’, dholes were bounty-hunted across the India until they were protected under the Wildlife (protection) Act, 1972. Because dholes are pack-living animals and because individuals are hard to distinguish from appearance, studying their populations pose many difficulties. A recent study by researchers from Wildlife Conservation Society, India and the National Centre for Biological Sciences examined dhole distribution patterns at two levels: (1) Occurrence at a landscape scale in the Western Ghats of Karnataka, and (2) fine-scale habitat-use within the Bandipur Tiger Reserve, also in Karnataka. The study also evaluated ecological and human-induced factors that drive these patterns.
Over 4174 km of roads in the Western Ghats landscape and 730 km within Bandipur were surveyed to make separate assessments at the two levels. Relative numbers of prey species preferred by dholes (chital and sambar) along with human disturbance were measured as potential factors that influence their use of space. The study used advanced habitat occupancy models to estimate and understand these distribution patterns.
At the larger landscape-scale, dholes occupied nearly 68% (14,185 sq. km) of the Western Ghats in Karnataka. Presence of chital was a very strong influence in determining their occurrence. But chital are found mostly in flatter areas. In locations with low densities of chital, sambar compensates as primary prey. Although dholes occurred in many non-protected forest areas (reserve forests, degraded and multi-use forests), there was also clear evidence to support their avoidance of areas with human disturbance. At the smaller scale within Bandipur reserve, on an average, dholes used about 71% of the park area. Human disturbance was the most important factor influencing habitat-use. At this scale, the preferred prey species did not particularly determine their patterns of space-use. This may be attributed to the fact that Bandipur has high densities of ungulates and these prey species are abundantly distributed across the park.
The results showed that Western Ghats currently supports a healthy meta-population of dholes. As with other wide-ranging species like tigers and elephants, forest connectivity is important for their populations to persist. Loss of forest cover outside protected areas may isolate their populations. Dholes currently occur in many areas that are in close proximity to human habitations. Since these areas also have some of the highest numbers of village/feral dogs, dholes stand the risk of contracting lethal diseases from their domestic cousins. This aspect of disease dynamics needs to be studied further to better understand dhole ecology. Even though Bandipur is a fairly well protected park, there are stray cases of human intrusions. These appear to negatively influence dhole habitat-use patterns. A lot of conservation and management funds are spent in activities like increasing artificial waterholes and forage availability to increase animal populations. Prey species in Bandipur are in optimum capacities and these funds should rather be used for increasing and strengthening protection efforts.
The results from this research provide key insights into the ecology of one the least studied carnivores in the world. The study also establishes that the Western Ghats region is a potential long-term conservation area and a population stronghold for dholes, both in India as well as across their geographic range.
Citation: Srivathsa A, Karanth KK, Jathanna D, Kumar NS, Karanth KU (2014) On a Dhole Trail: Examining Ecological and Anthropogenic Correlates of Dhole Habitat Occupancy in the Western Ghats of India. PLoS ONE 9(6): e98803. doi:10.1371/journal.pone.0098803