Cameras were clicking in central Washington
March 13, when state Fish and Wildlife officials released 20
endangered Columbia Basin pygmy rabbits. Onlookers, enamored with
the creatures’ fuzzy ears and dark eyes, were “just
like paparazzi,” says Madonna Luers, department spokeswoman,
“bunny paparazzi.”
The reintroduction was the
culmination of a captive breeding program designed to save the rare
rabbit, which is small enough to fit on a human hand (see a photo
in an earlier
HCN story). It’s the only rabbit
in North America to dig its own burrows.
The state granted
the Columbia Basin pygmy rabbit protection as an endangered species
in 1993, after a decline attributed to loss of shrub-steppe
habitat, fire, inbreeding and disease. In 2002, state biologists
collected 16 of the remaining rabbits to begin a breeding program.
The next year, the U.S. Fish and Wildlife Service declared the
Columbia Basin pygmy rabbit an endangered distinct population
segment. It’s the only federally protected pygmy rabbit; a
petition to list the entire species failed because the agency said
it provided insufficient information.
Rabbits being
rabbits, officials initially thought that it wouldn’t take
long for the captives to produce hundreds of offspring, says Luers.
But reproduction wasn’t as successful as anticipated. In
fact, numbers declined. The rabbits lacked genetic diversity, says
Ken Warheit, geneticist for the state’s Department of Fish
and Wildlife. Scientists concluded that inbreeding was leading to
shorter breeding seasons, longer mating rituals, and increased
susceptibility to disease; in essence, ineffective bunny sex.
So the scientists introduced three Idaho pygmy rabbits
into the Columbia Basin captive breeding project in hopes of
diversifying the genetic makeup. The rabbits released on March 13
are 75 percent Columbia Basin and 25 percent Idaho pygmy rabbits.
To retain federal protection, all animals released in the wild must
be at least 75 percent Columbia Basin pedigree.
The state
Department of Fish and Wildlife and Washington State University are
using radio transmitters to monitor the 20 rabbits. So far, raptors
have picked off five rabbits. But three males have set out to find
mates, traveling up to five miles off the Sagebrush Flat Wildlife
Area release site, and two of the females appear to be preparing
for kits by digging natal burrows.
Seventy pygmy rabbits
remain in the captive breeding program, and the next batch could be
released as early as this fall. Luers emphasizes, though, that the
program has a lot of work ahead: “Putting a couple dozen
rabbits out,” she says, “that’s a drop in the
bucket.”
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