US Fish & Wildlife Service


Date of this Version



Tretten TN. 2018. Rarely observed behaviors and occurrences of black-footed ferrets preconditioning for wild release 2014–2017. Journal of Fish and Wildlife Management 10(1):241–249; e1944-687X. 042018-JFWM-030


Black-footed ferrets Mustela nigripes became extinct in the wild in 1987 when the last known wild animals were removed from a remnant population in an attempt to save the species by beginning a captive breeding program. Breeding efforts were successful, and since 1991 wildlife managers have annually released ferrets back into the wild at sites within the ferrets’ historic range. Before their release into the wild, ferrets undergo a preconditioning stage in a quasi-natural habitat which better prepares them for life in the wild after a captive upbringing. Due to their nocturnal, fossorial, and largely solitary lifestyle, combined with their expansive habitat and endangered status, there are undoubtedly a multitude of behaviors ferrets exhibit that are not commonly observed. Here I detail multiple aspects of rarely described black-footed ferret ecology including black-tailed prairie dog Cynomys ludovicianus hunting stratagems, interactions with prairie rattlesnakes Crotalus viridis viridis, predation on birds, and sudden unexplained deaths of entire ferret family groups. The preconditioning setting that serves as an intermediate step between a captive and wild life for captive-reared ferrets allows for wildlife managers to witness ferret behaviors, though similar situations conceivably occur somewhat regularly in the wild.