Effects of highway traffic on diurnal activity of the critically endangered Przewalski's gazelle

Abstract

Highway traffic is considered to be one of the factors that influence survival of wildlife. Przewalski’s gazelle is a critically endangered species that lives in the Qinghai Lake watershed of western China. To learn the impacts of traffic on activity patterns of Przewalski’s gazelle, we investigated the relationship between traffic flow and diurnal behaviours of the gazelle on the eastern shore of Qinghai Lake, where a highway was built in 2002. During the summers of 2005 and 2006, we collected traffic data on the highway and observed the activity of the Przewalski’s gazelle population in the area. The results of statistical analysis showed the following: (1) frequency of behaviours such as standing, locomotion, foraging and resting differed among the 15 1-h sampling periods (daytime); (2) numbers of total vehicles, heavy vehicles and light vehicles were significantly different among the daytime hours; (3) there was a positive correlation between the frequency of resting of the gazelles and the number of passing vehicles, and a negative correlation between the frequencies of foraging and alert responses and the number of passing vehicles; (4) by comparing our results with those of a previous study on the gazelles at this site, before the construction of the highway, we found that the diurnal rhythms of foraging, standing and resting have changed markedly (e.g. the three peaks of foraging at 1300, 1600 and 1800 hours in 1996 changed to two peaks of foraging at 0600 and 2000 hours). Our results suggest that the highway traffic may have caused a change in diurnal activity of Przewalski’s gazelle, with the animals tending to keep away from the highway when the traffic flow is high. We suggest traffic-control measures to reduce disturbance to, and thus enhance conservation of, this highly threatened species.