Abstract:Infrared thermography (IRT) is a non-invasive and non-contact method for measuring surface temperature by absorbing the radiation heat from the surface of objects and transferring into thermogram (Fig. 1). Thermography has numerous practical applications in animal thermal physiology and wildlife monitoring. During the breeding season from April to August 2015, we searched for bird nests across four types of habitat in Kuankuoshui National Nature Reserve, southwestern Guizhou, China. During our work, we first used portable thermal image by IRT to scan for the nests within 5 m along the paths with possible nests been shown obviously (Fig. 1), then we carefully searched for the nests again by eyesights in the same area. A total of 54 bird nests were found, of which only 7 nests were recorded in thermal image and the searching success rate by IRT was 13.0% (7/54, Table 1). The highest searching success rate by IRT was for ground nests (27.3%, 3/11) and the lowest for tree nests (0%, 0/5). The vegetation coverage of nests found by IRT was significantly lower than that by traditional searching method (t = 2.837, df = 16, P < 0.01), and there was also significant difference in nesting site temperature D-value (t =﹣2.476, df = 19, P < 0.05) between them. Our results showed that vegetation density and temperature D-value of nesting site had important effects on searching success rate by IRT, with better searching success rate under lower vegetation cover and higher temperature D-value.