Prey selection by the steppe polecat Mustela eversmanni
YANG Sheng-Mei 1**, WEI Wan-Hong 1,3, YIN Bao-Fa1, FAN Nai-Chang2, ZHOU Wen-Yang31. College of Bioscience and Biotechnology, Yangzhou University, Yangzhou 225009, Jiangsu, China2. College of Life and Environment Science, Zhejiang Normal University, Jinhua 321004, Zhejiang, China3. Northwest Institute of Plateau Biology, the Chinese Academy of Sciences, Xining 810001, China
Prey selection and foraging behaviour of the steppe polecat Mustela eversmanni were investigated with plateau zokors Myospalax baileyi, plateau pikas Ochotona curzoniae and root voles Mirotus oeconomus offered as preys for paired comparisons in the laboratory. The time and frequency of the polecat searching different preys and burrows were nearly the same. The polecat attacked virtually all prey offered and thus exhibited opportunistic foraging behaviour. However, it did not captured all prey with equal sequence. It first captured the zokor, then the pika and last for the root vole. In addition to using the typical musteline killing method of biting the nape of the neck, the polecat evolved a variety of killing methods suited to a range of prey types depending on the activity, size and anti-predation ability of prey. The zokor was bitten on the head, whereas the pika was killed by bites to the head or throat and the root vole was killed by bites to the head or chest. The time polecats pursued the root vole was the longest, followed by that used in pursuing the pika and the zokor. However, the time of the polecat used to kill prey was reversed for the three prey species. So the polecat depended on its prey handling time and behaviours of prey to select the prey and get the largest net food value.