野外使用红外热成像仪搜寻鸟巢实验

红外热成像仪是一种非接触、无损伤性的温度测量仪,它可通过接收被测物体表面的热辐射形成热谱图,对研究对象进行定性观察或定量分析。热成像仪在野生动物调查和实验研究等领域均有应用。我们于2015年4~8月的鸟类繁殖季,使用手持便携式红外热成像仪,对贵州宽阔水国家级自然保护区内4种生境的鸟巢进行系统搜索。共找到鸟巢54个,其中7巢可在红外热成像仪中清晰显示。使用红外热成像仪搜寻鸟巢的成功率为13.0%(7/54)。其中,搜寻地面巢的成功率最大(27.3%,3/11),树上巢的成功率最低(0%,0/5)。在热谱图中所显示的巢,其植被郁闭度显著小于红外热成像仪搜寻不到的巢(t=2.837,df=16,P0.01);而其温差则显著大于红外热成像仪搜寻不到的巢(t=﹣2.476,df=19,P0.05)。这表明,使用红外热成像仪搜寻鸟巢主要受巢上植被郁闭度及巢周围环境温度的影响。巢上植被郁闭度越小,与周围环境的温差越大,则搜寻成功率越高。

A Test for Using Thermal Image by Infrared Thermography to Search Bird Nests

Infrared thermography (IRT) is a non-invasive and non-contact method of measuring surface temperature, which can absorb the radiation heat from the surface of objects and transfer into thermogram. 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 Nature Reserve, southwestern Guizhou, China, using portable thermal image by IRT. 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 12.9%. The highest searching success rate by IRT was for bird ground nests (27.3%, 3/11) and the lowest for tree nests (0%, 0/5). The vegetation coverage of nests found by IRT were significantly lower than those by traditional searching method (t=2.837, df=16, P=0.006), and there was also significant difference in nesting site temperature D-value (t=-2.476, df=19, P=0.023) between them. Our result showed that vegetation density and temperature D-value of nesting site had important effect on searching success rate by IRT. Lower vegetation cover and higher temperature D-value make a higher searching success. To our knowledge, this is the first report in China on bird nest survey in the field using portable thermal image by IRT.