PORTLAND, Ore. - Hundreds of endangered spotted frogs will be released into the wild after they were raised at the Oregon Zoo and prepared for reintroduction.
The frogs were collected as eggs and then as tadpoles, they hatched under the watchful eyes of zookeepers.
The Oregon Zoo is working to help save the species imperiled by loss of habitat, invasive predators and the deadly chytrid fungus (Batrachochytrium dendrobatidis), which has quickly spread from Africa to threaten amphibian populations worldwide.
"The chytrid fungus is definitely present in the Oregon spotted frog population. We don't know yet how much mortality it's causing," said David Shepherdson, deputy conservation manager at the Oregon Zoo.
The zoo plans to released the frogs in late September, into a wetland in Olympia, Wash.
"We hope they'll have a better chance of surviving through breeding age next spring," Shepherdson said.
"The Washington Department of Fish and Wildlife has been progressive in facilitating the program to recover its struggling Oregon spotted frog population," added Tony Vecchio, zoo director.
One of the most devastating threats is the non-native bullfrog, a larger species that has spread throughout the West Coast and eats other juvenile amphibians.
"The Oregon spotted frog is the most threatened frog in the Pacific Northwest," Shepherdson said. "It has special habitat requirements that bring it into proximity with bullfrogs."
The Oregon spotted frog is considered an endangered species in Washington and is a federal candidate for listing under the Endangered Species Act. For the past decade, the Oregon Zoo has been working with Washington Department of Fish and Wildlife amphibian biologist Marc Hayes to monitor the species' annual population and define strategies for recovery.
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. All told, the zoos hope to release up to 1,000 amphibians back into the wild this year, with more planned over the next several years.
Restoring the population is only one of the steps necessary to saving the species, Sherpherdson says. "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."
