Brown Treesnake counts during visual encounter surveys at three walking paces, Guam 2016

We evaluated three walking paces to estimate (1) how snake detection rate per unit distance changes with increasing pace, and (2) how total number of snakes found by the end of a night of surveying varies with pace when the amount of surveying time per night is held constant. For a ?fast? pace we searched the 220 meter-long transect in 10 minutes, corresponding to a walking pace of 1.32 km/h, whereas for a ?medium? pace we searched 17.5 minutes, corresponding to a pace of approximately 0.75 km/h. The ?slow? pace was the 30 minutes (0.44 km/h) the standard previously adopted for work on Guam. Perch height and sizes of detected snakes were recorded for the three paces.

本研究设置三种步行行进速度，旨在探究两个核心问题：其一，单位距离内的蛇类检出率如何随行进速度提升而变化；其二，在每晚野外调查时长固定的前提下，整晚调查结束时发现的蛇类总数量如何随行进速度改变。其中“快速”行进组：以10分钟完成220米长的样带（transect）调查，对应步行速度为1.32千米/小时；“中等”行进组耗时17.5分钟完成同一样带调查，对应速度约0.75千米/小时；“慢速”组耗时30分钟，对应速度0.44千米/小时，为此前关岛相关研究采用的标准行进速度。针对上述三种行进速度，本研究同步记录了被检出蛇类的栖息高度与体型大小。