Monitoring wildlife abundance and diversity with infra-red camera traps in Guanyinshan Nature Reserve of Shaanxi Province, China

Abstract

Ecological indicators or indices have been widely used to simplify and measure complex ecosystems. It is critical to identify suitable indicators or indices to improve monitoring and understanding of complex natural systems. Camera trapping is an objective technique that can provide a large amount of information on wildlife. The purpose of our study is to explore the effective ecological indices for wildlife diversity analysis and monitoring in Guanyinshan Nature Reserve of Shaanxi Province, China. Since July 2009, a total of 18 cameras were installed in the reserve from August 2009 to July 2011, collecting 2115 photo captures during these 24 months. We developed five abundance indices, including relative abundance index (RAI), monthly relative abundance index (MRAI), time-period relative abundance index (TRAI), night-time relative abundance index (NRAI) and species abundance index (N) to integrate the information derived from captures. Results are: (1) 27 species were detected and 6 species had high RAI values of over 79.3%, including takin (Budorcas taxicolor), common goral (Naemorhedus goral), tufted deer (Elaphodus cephalophus), golden pheasant (Chrysolophus pictus), wild boar (Sus scrofa), and mainland serow (Capricornis sumatraensis). (2) MRAI shows a consistent monthly activity pattern of all animals being active in June and July and inactive in February. (3) TRAIs of the most abundant six species show that takin, tufted deer and common goral have the similar daily activity pattern with one peak at dawn and one peak at dusk. The daily activity patterns of golden pheasant and wild boar show that they are most active during the day time, with wild boar being particularly active at noon. NRAIs of mainland serow show the highest nocturnality and of golden pheasant the lowest nocturnality. (4) We estimated abundance of takin, tufted deer and wild boar by using our developed index. The abundance for the three species shows an increasing trend during the 2-year study period, particularly for wild boar. Our results provided an interesting comparison of species diversity and their activity patterns. As trapping continues we will have a consistent source of monitoring data to evaluate changes in species abundance and activities. Therefore, the conclusion is that the methods we used and the indices we developed are capable to estimate species activity patterns and abundance dynamics which are useful for future wildlife management in Guanyinshan Nature Reserve and elsewhere.