Columbia Basin pygmy rabbit
The Columbia Basin pygmy rabbit is an isolated population of pygmy rabbit (Brachylagus idahoensis), that is native only to a single Columbia Basin area of Washington state. The Columbia Basin pygmy rabbit is the smallest North American rabbit. While the IUCN considers the species as a whole to be of least concern, the US Fish & Wildlife Service considers this a distinct population segment, and as thus merits protections under the Endangered Species Act. The last purebred Columbia Basin pygmy rabbit died in 2008, marking the end of the pure genetic line.
Pygmy rabbits are the only North American rabbits that dig burrows and live in a sagebrush habitat. In the wild, pygmy rabbits eat sagebrush almost exclusively in the winter; during summer, they eat a more varied diet. They may have two to four litters of about two to six kits during the spring and summer breeding seasons. Population decline is widely attributed to predation and habitat loss caused by agricultural development and wildfires. source