A conservationist releases a rare Oregon
spotted frog into a wetland at Joint Base Lewis-McChord. Photo by
Michael Durham, courtesy of the Oregon Zoo.
Oregon Zoo Releases Endangered Frogs into the WildSept 30, 2010
Contacts: Bill LaMarche 503-220-2448 (office) or
Linda D’Ae-Smith 503-220-5716
(office) or 503-441-7573 (pager)
PORTLAND, Ore. –– As eggs, they were rescued from the perils
that have all but decimated their population. As tadpoles, they hatched under
the watchful eyes of zookeepers. Now, hundreds of Oregon spotted frogs (Rana pretiosa) have
developed their land legs and taken a big leap back into the wild, where
conservationists hope they will have a fighting chance. The Washington
Department of Fish and Wildlife released more than 1,300 frogs into the wild
this week, including more than 230 that had been reared at the Oregon
“Oregon spotted frogs are disappearing from the wild at an
alarming rate,” said Kim Smith, zoo director. “By working with WDFW and our
conservation partners, we hope to boost the Pacific Northwest’s spotted frog
population and reverse the damage done by loss of habitat, invasive predators
and the chytrid fungus.”
Considered endangered in Washington and Canada, threatened in
Oregon and a candidate for listing under the federal Endangered Species Act, the
Oregon spotted frog faces an uncertain future. Over the past 50 years, the frogs
have lost around 90 percent of their previous habitat; non-native American
bullfrogs and game fish are among the predators putting the species in peril. In
addition, the chytrid fungus (Batrachochytrium dendrobatidis) has quickly
spread from Africa to threaten amphibian populations worldwide, and it is
present in the Oregon spotted frog population.
“The Oregon spotted frog is the most threatened frog in the
Pacific Northwest,” said Dr. David Shepherdson, Oregon Zoo conservation
scientist. “It has special habitat requirements that bring it into proximity
with bullfrogs. The key to reestablishing spotted frogs in the wild is nurturing
the frogs in zoos until they are fully metamorphosed yet not fully grown. They
have a much better chance of survival if they’re released as frogs rather than
For the past 13 years, Shepherdson has been working closely
with WDFW amphibian biologist Dr. Marc Hayes to monitor the species’ annual
population and define strategies for recovery, ensuring that field aspects of
the program have sufficient volunteer assistance for egg-mass surveys and
“Much of the conservation partnership’s success is linked to
the excellent relationship Dr. Shepherdson maintains with us,” Hayes said. “He
has been instrumental in engaging volunteers and keeping the Oregon Zoo involved
in the Oregon Spotted Frog Working Group.”
The process of collecting eggs, rearing tadpoles and
releasing frogs generally takes about six months and has achieved better results
each time. Conservationists are hopeful that progress will continue, allowing
the program to expand to other Northwest wetlands.
Last year’s release appears to have been a complete success,
according to Hayes. “There is no evidence of mortality among any of the tracked
frogs, and most have moved significant distances,” he said.
Even so, conservationists caution that restoring the
population is only one of the steps necessary to saving the species.
“We need to preserve more wetland habitats, increase the
health of the habitats by reducing pollution, and manage those habitats so
they’re less favorable to bullfrogs,” Shepherdson said.
Through a partnership with Joint Base Lewis-McChord, the
Dailman Lake area was chosen for reintroduction because it contains diverse
wetlands connected to a stream system capable of supporting and sustaining a
frog population, said Jim Lynch, wildlife biologist at Lewis-McChord.
“Frogs are found in all parts of the world and are known as
sentinel animals, alerting us to serious environmental and climate changes that
can affect all species,” Lynch said. “They also play an important role in
balancing ecosystems, and when they disappear from their habitat those
ecosystems are disrupted.”
reintroduction program, developed in 2007, is a collaborative effort by WDFW,
Joint Base Lewis-McChord, Northwest Trek Wildlife Park, Point Defiance Zoo &
Aquarium, Washington State Department of Transportation, U.S. Fish and Wildlife
Service, Woodland Park Zoo, Port Blakely Tree Farms, Washington Department of
Natural Resources, NW Zoo & Aquarium Alliance, U.S Geological Survey,
Mountain View Conservation & Breeding Centre and The Nature Conservancy.
The Oregon spotted frog captive-rearing effort is a project
of the NWZAA, which promotes collaboration on regional conservation among zoos
and aquariums in the Pacific Northwest. The zoos exceeded their goal of
releasing 1,000 amphibians back into the wild this year. They plan to build on
this success over the next several years.
Around 80 of the frogs
released this week were reared at Cedar Creek Corrections Center in Littlerock,
Wash. The Washington Department of Corrections recently received a grant from
the Oregon Zoo to continue rearing the frogs. The corrections center has had a
higher success rate at rearing the Oregon spotted frog than zoos and nature
centers in Washington, Oregon and British Columbia.
The Oregon Zoo has also opened an exhibit highlighting the
native amphibian and the efforts to save it.
“We hope the frogs on exhibit –– named Kirk, Spock and Scotty
by one of our keepers –– inspire visitors to join the zoo in its conservation
efforts,” Shepherdson said. “Much like their namesakes on ‘Star Trek,’ they
serve as ambassadors for their planet.”
Visitors can see the amphibian trio at the Cascade Stream and
Pond building of the Great Northwest Exhibit.
To watch a video of Oregon spotted frogs, visit: www.oregonzoo.org/VideoArchive/oregon_tadpoles.htm.
The zoo is a service of Metro and is dedicated to its mission
to inspire the community to create a better future for wildlife. Committed to
conservation, the zoo is currently working to save endangered California
condors, Washington’s pygmy rabbits, Oregon silverspot butterflies, western pond
turtles, Oregon spotted frogs and Kincaid’s lupine. Other projects include
studies on black rhinos, Asian elephants, polar bears and bats.
The zoo opens at 9 a.m. daily and is located five minutes
from downtown Portland, just off Highway 26. The zoo is also accessible by MAX
light rail line. Visitors who take MAX to the zoo receive $1.50 off zoo
admission. Call TriMet Customer Service, 503-238-RIDE (7433), or visit www.trimet.org for
fare and route information.
General admission is $10.50 (12–64), seniors $9 (65+),
children $7.50 (3–11), and infants 2 and under are free; 25 cents of the
admission price helps fund regional conservation projects through the zoo’s
Future for Wildlife program. A parking fee of $2 per car is also required.
Additional information is available at www.oregonzoo.org or by calling
# # #
AZA Members: Submit your Zoo & Aquarium News