Ernsting G, Jansen J W
Department of Biology, Free University, De Boelelaan, 1087, Amsterdam-Buitenveldert, The Netherlands.
Oecologia. 1978 Jan;33(2):173-183. doi: 10.1007/BF00344846.
Observations on predation by the diurnally active predator Notiophilus biguttatus F., show that locomotory activity of the prey favours capture. Of the two prey species studied, Orchesella cincta and Tomocerus minor, the former is by far the most active one during the day. Since the moulting rhythm causes only part of a group of O. cincta to be active, predation towards this species is selective: active specimens are "preferred". Tomocerus minor is almost inactive during the day (but may be activated by disturbance from the predator), which inhibits such a selection. Orchesella cincta also shows, when attacked, a greater escape ability than T. minor. So, inactive O. cincta are captured less easily than T. minor. Thus, locomotory activity and escape ability both cause a variable preference of the predator. When a sufficiently high number of active O. cincta specimens is present, this species will be preferred; when the number of active O. cincta specimens is low, e.g. as a consequence of predation, T. minor might be preferred.
对日间活动的捕食者双斑青步甲（Notiophilus biguttatus F.）捕食行为的观察表明，猎物的运动活动有利于被捕食。在所研究的两种猎物中，带纹奥甲螨（Orchesella cincta）和微小跳虫（Tomocerus minor），前者在白天的活动最为活跃。由于蜕皮节律只导致一部分带纹奥甲螨群体活跃，因此对该物种的捕食具有选择性：活跃的个体更“受青睐”。微小跳虫在白天几乎不活动（但可能会因捕食者的干扰而被激活），这抑制了这种选择。带纹奥甲螨在受到攻击时，也比微小跳虫表现出更强的逃脱能力。所以，不活跃的带纹奥甲螨比微小跳虫更不容易被捕食。因此，运动活动和逃脱能力都会导致捕食者产生不同的偏好。当有足够数量的活跃带纹奥甲螨个体时，该物种会更受青睐；当活跃的带纹奥甲螨个体数量较低时，例如由于捕食，微小跳虫可能会更受青睐。
