The Indian Grey Wolf and Striped Hyena known to be rival species are showing tolerant behaviour towards each other, in terms of the patches they occupy to utilise the livestock resource as prey in semi-arid regions of West Bengal, a recent study by scientists of Zoological Survey of India and the West Bengal Forest Department has pointed out.
The details of the study have been published in a paper titled, ‘Indian Grey Wolf and Striped Hyena sharing from the same bowl: High niche overlap between top predators in a human-dominated landscape’ published in international science journal Global Ecology and Conservation.
“We found that both the species, which are generally known rivals showing tolerance towards each other, which is a strong evidence of land sharing among the species in the landscape. We also found significant level of biological connectivity between the overlapping suitable habitat patches of both the species,” said Dr. Lalit Kumar Sharma, lead author and head of the wildlife section of ZSI.
The researchers divided the landscape in grids and used camera traps as well as DNA analysis of scats to record the presence of both the species. The GPS (global positioning system) coordinates of all the 262 presence records such as direct sightings and indirect evidence (camera trap pictures, scat) of both the species were recorded. Of the total presence records, 189 observations were found confirmed for wolf combining both 72 direct and 117 indirect observations. In case of hyena there were 73 records, 27 direct observation and 46 indirect. The researchers conducted interviews of about 1,356 respondents on species presence and also to document carnivore-human conflict case.
Camera trap images of Indian Grey Wolf.
“Our model also brought out that much of the species suitable habitat lies within the human-modified lands. Moreover, the highest level of biological connectivity resides between Purulia and Bankura district, indicating the species use a human-dominated landscape for movement among suitable habitat patches. Further presence of a high level of niche overlap and occurrence of biological corridors in the anthropogenic landscape can be attributed to poor wild prey availability, increasing human colonization and mining activities in study region,” the paper said.
Debal Roy, chief project director, West Bengal Forest and Biodiversity Conservation Project, said the study was conceptualised four years ago when he along with colleagues came across the presence of these animals in the wild and did not know much about their habitat utilisation connectivity and gene flow between the populations. Mr. Roy, who is also one of the authors of the study, said that based on the outcome of the study the State forest department will take up effective management of both species.
Along with the niche overlap of the two species, the publication also gives an idea of the corridor analysis of both. The maximum biological connectivity for hyena may exist between the large habitat patch distributed in western Purulia. Patches of the southern area of Bankura Marginal connectivity may also exist among the smaller patches present on the northern side of Bankura-Purulia. In case of the Grey Wolf, biological connectivity may exist in habitat patches distributed in the western part of Purulia with the southern region of Bankura, which continues up to Jhargram district.
The researchers said they have not encountered any cases of cooperative hunting between the two species but added the possibility can’t be ruled out and recommended more intensive camera-trapping studies and radio telemetry-based study in the study landscape to better understand landscape utilisation and the feeding behaviour of both species.
The paper that has been authored by 12 experts — including Mukesh Thakur, Tanoy Mukherjee, Bheem Dutt Joshi, and Kailash Chandra, former director of ZSI — revealed that many suitable habitats for both species are not protected and under high anthropogenic pressure. The increasing involvement of these two large carnivores in the human-dominated landscape is a significant threat to their long-term viability. In addition to increasing human-wildlife conflict, illegal hunting by the local tribal communities during the Shikar festival may result in the extirpation of these two species in the landscape.
“Hence, it is imperative to adopt best practices pertinent to wildlife conservation into the working plans of these identified areas. We recommend that the suitable patches and corridors identified in the study may be prioritized for conservation and management,” Dr. Sharma said.
