Immediate behavioural responses of humans and Asian elephants in the context of road traffic in southern India
Introduction
Highways in various regions of the world have been linked to declines in animal density (for example, Fahrig et al., 1995, Reijnen et al., 1995), mortality of various taxa (for example, Davies et al., 1987, Groot Bruinderink and Hazebroek, 1996; see Trombulak and Frissell, 2000), and creation of barriers to movement between habitat patches (for example, McLellan and Shackleton, 1988, Mace et al., 1996, Forman and Alexander, 1998, Rondinini and Doncaster, 2002, Shepard et al., 2008). Human–wildlife conflict due to vehicular movement is an increasing concern in India, a country with abundant biodiversity, a human population of over one billion, and only about 4.7% of its land area classified as “Protected Areas” for wildlife (National Forest Commission, 2006). With roads running through Protected Areas and a trebling of the number of motor vehicles in India since 1990 (Pucher et al., 2007), the need for reconciling economic growth and wildlife protection on India’s highways has perhaps never been greater.
While studies of the effect of road traffic on wildlife have tended to focus on mortality of wildlife or fragmentation of habitat, little attention has been paid to immediate behavioural responses of motorists and wildlife. Studies of behavioural responses of wildlife have focused more on the response of wildlife to roads, such as avoidance of roads (for example, McLellan and Shackleton, 1988, Brody and Pelton, 1989, Barnes et al., 1991, Klein, 1991, Blake et al., 2008) or decreased utilization of surrounding areas (Van der Zande et al., 1980, Madsen, 1985), than actual interaction with motorists. Studies of immediate behavioural responses to road traffic by wildlife are few and have usually been in the context of traffic collisions with ungulates, which pose a grave problem to road-safety in the United States, Europe, and Japan (Waring et al., 1991; see Groot Bruinderink and Hazebroek, 1996). While there is significant mortality of animals from road traffic in India (Dhindsa et al., 1988, Boominathan, 1999, Vijayakumar et al., 2001), mortality of large mammals is not as common as in the United States or Europe since the topography and relatively narrow roads through forests prohibit high driving speeds, which are an important cause of collisions (Pojar et al., 1975, Case, 1978). We were more interested in how motorists and animals respond to each other behaviourally when they encounter each other since this would offer significant input to management from the point of view of raising awareness amongst motorists as well as reducing disturbance to wildlife and preventing traffic collisions with them. For instance, an understanding of the disturbance created by different types of motorists (locals versus visitors, passengers versus goods, and in a range of group sizes using vehicles of different sizes) would allow for a targeted awareness programme. Similarly, an understanding of what animals are disturbed by, such as motorist action, vehicle size, and distance to which they are approached, under different circumstances, such as the animal’s group composition and whether it has had access to water/forage, would allow us to make informed decisions about the levels of traffic permissible and their management, spatially and temporally.
The present study focused on Asian elephants (Elephas maximus) because they are wide-ranging animals that frequently encounter roadways and vehicular traffic. Requiring the use of large areas, elephants are expected to be affected to a great degree by habitat fragmentation. Being charismatic megafauna, they are also expected to elicit strong responses from motorists. On the other hand, their size and strength allow them to retaliate to some extent towards road traffic, making them an ideal species for studying motorist–wildlife interactions. In addition, Asian elephants are not the most behaviourally sensitive of species to human influence and share habitats with humans in several areas. Therefore, their behavioural response would serve as a minimum disturbance scenario, with many other species probably being affected to a greater degree. In this study, we wanted to find out how different categories of motorists behaved towards elephants, what determined the responses of elephants towards motorists, and to test if these responses from elephants were directly related to motorist behaviour. We predicted that passenger vehicles would create more disturbance than goods vehicles and visitors more than locals, and that elephant response would reflect motorist response.
Section snippets
Study area
The study was carried out in Mudumalai Wildlife Sanctuary (now Mudumalai Tiger Reserve) (11°31′N–11°39′N, 76°27′E–76°43′E; area of 321 km2; altitude of 850–1250 m above mean sea level), which is located centrally in the Nilgiris-Eastern Ghats landscape in southern India. The reserve is home to Asian elephants in one of the highest densities recorded (∼2 elephants/km2) and is believed to have a high conservation value (AERCC, 1998). The reserve, which lies in the state of Tamil Nadu and is
Behavioural response of motorists
A total of 1521 motorist–elephant interactions were observed during the study period based on 76 sightings (379 individuals; these were the number of individuals that came out towards the road but it is possible that these groups had more elephants that were still further into the forest and thus not visible at the time of observation) of elephant groups. We observed an average of 4.6 (SD = 5.51) interactions per hour of field effort. The number of motorists elephants interacted with per hour on
Elephant response
While it is known that various large animals such as grizzly bears (McLellan and Shackleton, 1988), black bears (Brody and Pelton, 1989), caribou (Klein, 1991), and African forest elephants (Barnes et al., 1991, Blake et al., 2008) avoid roads, and that elephants in our study site avoided highways during the daytime (Boominathan, 1999), this is one of the few studies that examined immediate behavioural responses to land-, water-, or air-borne vehicles. Previous studies on immediate behavioural
Acknowledgments
We are grateful to the Animal and Plant Conservation Division, Chester Zoo, North of England Zoological Society for funding the field study. We thank the Tamil Nadu Forest Department for a research permit and R. Dogra, I.F.S., wildlife warden of Mudumalai Wildlife Sanctuary, and other forest department officials and staff for their support. VT was hosted at the Indian Institute of Science Field Research Station in Masinagudi during the field study. R. Arumugam, C. Arivazhagan, and C. M.
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