Camera-trap study shows dholes too have a home range

 It is usually believed that only big cats have a home range. But the home range of dholes too has been established for the first time by a team of researchers using the camera-trap methodology.

This has been published in a field report titled – Home range size of the dhole estimated from camera-trap surveys – by Arjun Srivathsa, N Samba Kumar and K Ullas Karanth, from the Centre for Wildlife Studies and Wildlife Conservation Society. The study also appears in the January issue of the international journal Canid Biology and Conservation.

The study, based on intensive camera-trap surveys conducted in Nagarahole and Wayanad wildlife reserves in the Western Ghats, was part of a long-term project on tiger population dynamics in the region.

Srivathsa said that typically, radio-telemetry is used to obtain information on home range sizes of large carnivores such as dholes. “This is expensive and requires careful handling of animals. In contrast, our estimates are generated through innovative use of non-invasive and relatively inexpensive camera-trap pictures,” he said.

For a duration of 45 days, between November 2014 and January 2015, researchers set up and monitored camera-traps which yielded incidental photographic captures of dholes. Unlike tigers or leopards, individual dholes cannot be uniquely identified from camera-trap photographs because they do not have pelage patterns or natural body markings. Yet, researchers were able to identify two individuals in a pack of five animals, based on distinct markings on their pelage, enabling them to map locations of the pack during the survey period and estimated their home range size of around 85 sq km.

The study also points that the home range size of dholes may vary as a function of prey species, and possibly other habitat characteristics, as well as pack size. For instance, dholes in central India have large annual home ranges, between 40 and 200 sq km, generally showing seasonal variations. Some studies in the central part of Western Ghats also show that dhole packs appear to have much smaller home range sizes (seasonally between 20 and 60 sq km), a likely consequence of high densities of ungulate prey in these well-protected deciduous forest reserves.