The question of how to program the removal of two invasive mammals, typically cats and rats, from a marine island without increasing risk to native prey species has received two general answers based on ecological theory: removal of cats must be accompanied by control of their mesopredator prey, and risk is minimized by removing both invaders simultaneously. Nonetheless, a 31-year study showed that in a 82-ha tropical marine bird sanctuary, predation on a native prey, the blue-footed booby, by a native predator, the Atlantic Central American milk snake, apparently diminished after removal of cats then increased 11-fold after the additional removal of black rats. These novel effects are explained in terms of a hypothetical three-link trophic web in which cat removal released rats to increasingly compete with or prey on the snakes that feed on hatchling boobies, and subsequent rat removal released snakes from all remaining predation. The upshot is a disturbing scenario in which approximately 200 milk snakes currently aggregate annually in roughly 1 hectare of booby colony and predate roughly forty percent of the hatchlings. Where the lowest link of an insular trophic web is a native mesopredator that feeds on native prey, the predictions of the classic mesopredator release scenario can be inverted, and removal of invasive mammals may endanger native prey species.

基于如何从生态学原理出发，如何在不增加本地捕食物种风险的情况下，如何从海洋岛屿中清除两只侵入性哺乳动物（通常是猫和老鼠）的问题，已经得到了两个普遍的答案：猫的清除必须伴随着它们的中性繁殖体的控制同时移除两个入侵者，将风险降到最低。尽管如此，一项为期31年的研究表明，在一个82公顷的热带海洋鸟类保护区中，本地掠食者大西洋中美洲奶蛇对本地猎物蓝足笨蛋的捕食在去除猫后显然减少了，额外移去黑色大鼠后，其数量增加了11倍。这些新的效应是通过一个假设的三链营养网来解释的，在该网中，猫的去除释放了老鼠，使其越来越多地与以孵化雏鸟为食的蛇竞争或捕食，随后的老鼠去除了蛇，使蛇从所有剩余的捕食中释放出来。结果是一个令人不安的情况，目前每年大约有200条奶蛇聚集在大约1公顷的诱杀种群中，并且早于约40％的孵化场。在岛状营养网的最低链接是靠本地捕食者为食的本地捕食者的情况下，对经典中捕食者释放情况的预测可以被颠倒，入侵性哺乳动物的移走可能危及本地捕食者的物种。结果是一个令人不安的情况，目前每年大约有200条奶蛇聚集在大约1公顷的诱杀种群中，并且早于约40％的孵化场。在岛状营养网的最低链接是靠本地捕食者为食的本地捕食者的情况下，对经典中捕食者释放情况的预测可以被颠倒，入侵性哺乳动物的移走可能危及本地捕食者的物种。结果是一个令人不安的情况，目前每年大约有200条奶蛇聚集在大约1公顷的诱杀种群中，并且早于约40％的孵化场。在岛状营养网的最低链接是靠本地捕食者为食的本地捕食者的情况下，对经典中捕食者释放情况的预测可以被颠倒，入侵性哺乳动物的移走可能危及本地捕食者的物种。