The US Fish and Wildlife Service recently completed a five-year study on the status of the Columbia Basin Pygmy Rabbit. Perhaps the country's most endangered lagomorph, the Washington state rabbit has been on a watchlist of endangered species since 1993. Wild populations of the animal have been extinct since 2004. These tiny creatures, weighing less than one pound in adulthood, have been bred in the Oregon Zoo, Northwest Trek, and Washington State University since that time, although they have not fared well in captivity. To prevent inbreeding, the rabbits have recently been bred with other species of pygmy rabbits, but diseases hidden in their burrows' soil have extinguished many of the new lives.
In 2007, twenty of the captive-bred rabbits were released into the wild in an area where the species was previously known to dwell. Unfortunately, because of the small size of both their bodies and the size of the released population as a whole, it is believed that none survived very long after their release. Further releases into the wild are being considered, but it is unlikely that the next round of pygmy rabbits will do any better against predators this time around.