The Elusive Long-tailed Weasel

The story begins when an infant weasel was brought to NAR on April 3 by a local family who found him—thinking he was a squirrel—on the ground near their home in Watsonville. The baby weasel, known as a “kit,” was no more than seven days old with eyes shut, without teeth, and nearly hairless. Raising this weasel from infancy to independence took about three months and carefully planned pre-release conditioning. 

First 4 weeks: The infant. During his first four weeks of life, his caregivers fed him every two hours around the clock. His high-protein feedings included a special milk formula and canned cat food made of mice. His markings, weasel fur, and teeth emerged in about week three, but his eyes remained shut until the end of the fourth week. 

Weeks 5, 6, and 7: The juvenile. After his eyes opened in week four, his caregivers moved him to a large outdoor enclosure at NAR filled with a network of tunnels and hiding spaces where he could practice hiding from predators (cats, hawks, owls, foxes, and coyotes) and hunting for food hidden by his caregivers. In his new large enclosure, he was extremely energetic and active for many hours each day. His caregivers introduced whole prey into his diet, and after a few weeks, they released live prey into his enclosure. In this short video, he’s practicing his hunting skills.  

Weeks 8 and 9: The sub-adult. At eight weeks, the caregivers transported him to the location in the Santa Cruz Mountains where he was ultimately released. This location was selected for its proximity to a year-round creek and good hunting grounds with abundant live prey. His caregivers began intensive pre-release conditioning to expose him to more aspects of life in the wild. In his new home, he was initially provided a nest box inside a large indoor enclosure filled with tunnels and hiding places where the caregivers continued to hide food and release live prey. Hiding from predators and catching and devouring live prey were critical milestones in his development. 

Week 10 to 13: The adult. In week ten, a tunnel to the outdoors was added to his enclosure so that he could go in and out whenever he wanted. It became especially important that he become adept at hiding from predators. The caregivers continued to provide food inside his enclosure. After two weeks, the caregivers moved the nest box outside and closed the tunnel so that the weasel could no longer return to his protected enclosure. In this “supported release,” he was able to put his hunting skills to work while relying upon a backup supply of food close to the nest box.

Week 14. Second chance at life in the wild. By the end of week 13, the weasel was surviving on his own in his new territory with a little backup support from his caregivers. Finally, his dependence upon his caregivers totally diminished. By week 16, the weasel was swimming across the creek, hunting, killing, and eating his own live prey. SUCCESS!!