We exposed naive Siberain polecats (Mustela eversmanni) (aged 2, 3, and 4 months) to a swooping stuffed great horned owl (Buho virginianus) and a stuffed badger (Taxidae taxus) mounted on a remote control toy automobile frame. The first introduction to each was harmless, the second was accompanied by a mild aversive stimulus, the third (1 day after attack) was harmless, and the fourth (30 days after attack) was harmless. Alert behavior increased after a single attack by either predator model. Escape responses of naive polecats did not differ between ages when exposed to the badger, but 4 month old polecats reduced their escape times after a single badger attack. When exposed to the swooping owl, naive 4 month old polecats redponded more quickly than the other two age groups, and 3 and 4 month old polecats reduced escape times after a single owl attack. This indicates an innate escape response to the owl model at 4 months of age, and a short-tert ability to remember a single mild aversive encounter with the badger and owl models at 3 or 4 months of age.