Mortality of Siberian polecats and black-footed ferrets released onto prairie dog colonies

摘要: Black-footed ferrets (Mustela nigripes) likely were extirpated from the wild in 1985–1986, and their repatriation depends on captive breeding reintroduction. Postrelease survival of animals can be affected by behavioral changes induced captivity. We released neutered Siberian polecats (M. eversmanii), close relatives ferrets, 1989–1990 black-tailed prairie dog (Cynomys ludovicianus) colonies Colorado Wyoming initially to test rearing reintroduction techniques. Captive-born reared cages or plus outdoor pens, elevated into burrows, supplementally fed not fed. also translocated wild-born China 1990 captive-born, cage-reared black-footed 1991, 1st such ferrets. documented mortality for 55 92 radiotagged these studies, mostly due predation (46 cases). Coyotes (Canis latrans) killed 31 polecats. Supplementally survived longer than nonprovisioned With a model based deaths per distance moved, was highest polecats, followed pen-experienced, then groups. Indexes abundance (from spotlight surveys) several predators correlated with rates those predators. Released had lower ancestral population Wyoming, emphasizing influence lost body mass more rapidly postrelease did captive-born Differences hunting efficiency prey selection provide further evidence that are ecological equivalents strict sense.