Situated north of Ephrata on state-owned lands in a sagebrush-covered coulee, Washington Department of Fish and Wildlife (WDFW) is successfully running an innovative, semi-wild pygmy rabbit recovery program, now in its 4th year. This is a collaborative effort with the U.S. Fish and Wildlife Service to reintroduce the endangered Columbia Basin pygmy rabbit sub-population to its former native habitat.
In the Western U.S, pygmy rabbits are native to the Great Basin’s arid sagebrush lands. Their diet is chiefly sagebrush leaves, making up 99% of their winter and >50% of their summer food. All needed water is obtained from plant food. They require sagebrush for cover, as a hiding place from predators. Most critically, they need the soft loose soil underneath sagebrush to dig out 3-inch diameter burrows, with multiple entrances. They are the smallest North American rabbit and are the only species that digs its own burrows. Females (450 grams) are larger than males (350 grams). Breeding begins in February, and after a 25-day gestation, up to six kits are born in a litter, in the burrow. Each day, the female leaves the burrow to feed and backfills the entrance, returning to re-excavate and enter the burrow to nurse the kits. Two weeks after birth, the juveniles emerge from the burrow and are on their own, weighing about 125 grams. Individual pygmy rabbits have a very small range, typically staying within 200 yards of their burrow system.
Pygmy rabbits play an important role in the biodiversity of sagebrush-grasslands. Other animals, like cottontails, gopher snakes, or short-horned lizards use former burrows. Predators like coyotes, hawks, and owls feed on pygmy rabbits. Insects like bot-flies are pygmy rabbit parasites, and as winged adults provide food for fly-catching birds. In Washington, birds like greater sage grouse, sage thrashers, and sagebrush sparrow require large patches of sagebrush for food and nesting habitat. Biologists hope to learn more about the role pygmy rabbits play in sagebrush ecosystems. What is the impact of their earth-moving? How do nutrients from their urine and feces cycle through native plants? Successful reintroduction of pygmy rabbits into Moses Coulee will allow such future research.
Every day, supporting pygmy rabbit health is JoAnn Wisniewski job description. She is the WDFW wildlife biologist in charge of the intensive captive rearing project at Sagebrush Flats. Her field offices are 6-10 acre enclosures of big sagebrush, surrounded by welded wire fencing that is buried 18 inches deep to keep coyotes out and rabbits in. The fence tops are rolled to deter weasels from climbing in to feast on rabbits.
Sections of black plastic drainpipe are used to supplement the rabbit-dug burrows. JoAnn runs feeding stations that are covered with netting to protect rabbits from aerial predators. In this concentrated rabbit-rearing area, supplemental food and water is provided, and leaf lettuce is given during hot days to keep rabbits hydrated. Starting in mid-spring during the cool early morning hours, juvenile rabbits are captured at burrow exits by volunteers wielding pillowcases. Juveniles are weighted and a tiny sample of ear tissue is taken for future DNA analysis. Young rabbits that make a minimumweight are transferred to portable kennels and driven a few miles away to a release habitat with suitable big sagebrush cover.
JoAnn’s day begins well before dawn and she works under the hot sun in an arid landscape. JoAnn’s is committed to preserving biodiversity, “I accepted this job to work with an endangered species because it is important not to lose any piece of the puzzle in this ecosystem.” She invites you to come spend a day with these small furry rabbits that are such fun to hold, and then watch as they scamper away in search of the safety of a big sagebrush. You can watch videos of pygmy rabbits and see more photos at: http://wdfw.wa.gov/conservation/pygmy_rabbit/videos.html
Byline: Biologist-educator Susan Ballinger teaches the Wenatchee Naturalist course through Wenatchee Valley College Continuing Education. Susan is teaching a 3-day field trip course in late June and a fall 12-week course with 4 all-day field trips, with daytime and evening options. Register at: https://www.wvc.edu/directory/departments/conted/