More than 1,300 endangered Oregon spotted frogs were released into the wild last week near Olympia with the help of the Woodland Park Zoo in an ongoing effort to re-establish their populations in Washington.

This year’s frog release is the most successful yet, with the number of frogs, average frog size and egg survival rates to adult frogs up from previous years’ captive rearing efforts, Washington Department of Fish and Wildlife Department senior research scientist Dr. Marc Hayes said in a Woodland Park Zoo press release.

“We continue to learn more every year as we work collaboratively to establish a self-sustaining population of frogs at Fort Lewis,” Hayes said in the press release.

The endangered frogs were collected from the wild as eggs by Washington Department of Fish and Wildlife biologists and placed at Woodland Park Zoo, Oregon Zoo, Northwest Trek and Cedar Creek Corrections Center for hatching and rearing as a “head start” to improve their chances of survival upon release back into the wild.

The Oregon spotted frog is near extinction due to loss of habitat, non-native predators and disease. The frog was listed as a Washington state endangered species in 1997 and is a candidate for federal listing.

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, Jim Lynch, wildlife biologist at Lewis-McChord, said in the press release.

Head starting the frogs and replenishing the wild population will require more to save this endangered species, according to the press release.

“We need to monitor and mitigate the factors that have led to the endangered status of these frogs, including habitat loss and pollution and the proliferation of invasive species," Nancy Hawkes, general curator at Woodland Park Zoo, said in the press release. "Local communities can help by avoiding the use of chemical pesticides in yards and reducing the pollution that impacts our local wetlands."

“Frogs are found in nearly all parts of the world and are known as sentinel species, alerting us to serious environmental and climate changes that can affect all species,” Lynch said in the press release.

The frog reintroduction program, initiated in 2007, is a collaborative effort by Washington Department of Fish and Wildlife, Joint Base Lewis-McChord, Northwest Trek Wildlife Park, Woodland Park Zoo, Oregon Zoo, Point Defiance Zoo & Aquarium, Washington State Department of Corrections, Washington State Department of Transportation, U.S. Fish and Wildlife Service, Port Blakely Tree Farms, Washington Department of Natural Resources, NW Zoo & Aquarium Alliance (NWZAA), 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.