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.

Metapopulation viability of a globally endangered gazelle on the Northeast Qinghai–Tibetan Plateau

“…The population decline and range reduction seen in Przewalski's gazelle have both been strongly influenced by human activities (Li et al, 1999(Li et al, , 2012You et al, 2013). This gazelle was once on the brink of extinction (Jiang et al, 2000) and now only a few remnant subpopulations remain (Li et al, 2012).…”

“…Paddock fences within the gazelles' range impair their ability to escape predators and can strangle individuals (Li et al, 2012;You et al, 2013). Przewalski's gazelles have changed their diurnal pattern of activities in response to human activities, shortening the average distance traveled each day, reducing the extent of habitat used, and reducing the duration of a given feeding bout, all of which may directly and/or indirectly heighten mortality (Li et al, 2009;You et al, 2013). This may be a simple passive response of the gazelles which would therefore endanger the survival of Przewalski's gazelle (You et al, 2013).…”

“…Considering the impacts of human activities and predators (Jiang et al, 2000;Li et al, 2009Li et al, , 2012, we set the survival rate of individuals migrating between subpopulations to 50%, and the minimum and maximum ages to 1 and 10 years old, respectively, for both male and female gazelles. Following Pergams et al (2000), we calculated migration rates between subpopulations (Appendix B) based on the rate of gene flow, as taken from Yang and Jiang (unpublished data).…”

“…Although Przewalski's gazelle was recently reclassified from Critically Endangered to Endangered by the IUCN, owing to the discovery of a few new subpopulations (IUCN SSC Antelope Specialist Group, 2008), its overall population size remains very small (Li et al, 2012). Integrating data from satellite-based remote sensing, topography, vegetation, land use and field surveys (Li et al, 1999), species distribution modeling (Hu and Jiang, 2010), and studies of population dynamics (e.g., Jiang et al, 2000;Li et al, 2012), the carrying capacity (K) for Przewalski's gazelle is estimated to be approximately 1850 individuals (also see Li and Jiang, 2002). This gazelle species still faces many threats.…”

“…Increasing numbers of domestic livestock within the gazelle's range has intensified food competition, especially in the winter (Li et al, 2008(Li et al, , 2012. Road networks that have fragmented the gazelle's habitat have changed the diurnal activity patterns of the gazelles (Li et al, 2009). Przewalski's gazelle may have limited ability to adapt to these and other environmental changes, since the genetic diversity of the nine known subpopulations (pre-2008; with the total population size estimated at 910 individuals ;Jiang, 2004;Li et al, 2012;Ye et al, 2006) is low, as is the gene flow between subpopulations .…”