Understanding the influence of tourism on behaviour and habitat use of Nilgiri tahr (Nilgiritragus hylocrius Ogilby, 1838) in Eravikulam National Park, Kerala

Abstract

Eravikulam National Park is the home for the largest number of Endangered Nilgiri tahr in the world (Predit et al, 2015; Saju,2012) and the park is also having an ecotourism programme dedicated for observing tahr at closer distance (Saju,2012). This population in the tourism area have high human interaction and have become habituated to the presence of humans. Habituation is known to influence the wild behaviour and instincts of animals (Shackley,1996; Knight,2009; Mazur, 2006; Marler & Hamilton,1966; Hingham & Shelton,2011) and this study was intended to understand the influence of tourism on the behaviour and habitat use of Nilgiri tahr in the Eravikulam National Park.The field work was carried for four months from January 2024 to April 2024, of which tourism was closed during the months of February and March, creating three sampling seasons: preclosing, closing and reopening season with varying human presence. Scan sampling and focal sampling (Altman, 1974) were carried out and observations of the population in tourism area were compared to the populations in Varattukulam region of core area which have minimum human interaction. The result showed a significant difference in the behaviour and habitat use between tourism and core area and also across tourism season. The activity pattern in the tourism zone is different from that of the core. Habitat use was also different as most of the behaviour in tourism area were not showing any significant relationship with a particular habitat unlike the population in core area. The flight distance in tourism area was also found to be very much shorter (1.8m) in compared to core area(118m) which is evidence for the extend of habituation tahr has gone through. Interestingly, the tourism adjacent hills which belonged to the same landscape as that of the tourism zone showed higher flight distance. The tourism zone also had high density of predators (Tiger and leopard) and there was spatial overlap between tahr and predators. Study was not able to prove the existence of human shield hypothesis (HSH) (Berger, 2007) as large carnivores were still present in the tourism area and even when tourism was closed, which reduced the number of people on the road, tahr were still coming to tourism area. However, tahrs were observed to be avoiding the carnivore by temporal separation as all camera trapping of predators happened during night time but no tahr was active at that time in tourism road.