Zoo readies 100 frogs for big leap back into wild

Head-start program gives endangered northern leopard frogs a leg up in the world

A hundred imperiled northern leopard frogs will be hopping back into the wild soon, thanks to a recovery program at the Oregon Zoo. The rapidly growing tadpoles were brought to the zoo as eggs earlier this spring by the Washington Department of Fish and Wildlife.

“Their development is right on track so far,” said Jen Osburn Eliot, who oversees the zoo’s Great Northwest area. “Soon they’ll be frogs, ready to hop back to the wild.”

Once abundant throughout North America, northern leopard frogs are rapidly disappearing from their native ranges in Washington, Oregon and western Canada. In Washington, the species has been listed as endangered since 1999.

“Wildlife officials bring the eggs to the zoo to give the frogs a better chance at survival,” Osburn Eliot said. “By caring for them through their most vulnerable stages, we can increase their chance of reaching adult size.”

More than 50 zoo-reared tadpoles were released at the Columbia National Wildlife Refuge in Washington earlier this year, while the remaining 100 will complete their transformation into frogs before returning to the wild next month.

“Each tadpole is important,” said Osburn Eliot. “There’s only one known population of northern leopard frogs left in Washington state, and we want to do everything we can to help bring them back.”

Though the reason for northern leopard frogs’ decline in the Pacific Northwest is unknown, they are threatened by habitat loss, disease, pollution, climate change and competition from non-native species. Recovery efforts by the zoo, WDFW, the U.S. Fish and Wildlife Service and Washington State University aim to increase their population in the region.

According to wildlife officials, northern leopard frogs are an important foundation species in natural ecosystems, an indicator of water quality, predator and prey, and a source of inspiration for wildlife enthusiasts around the world. 

Funding for the northern leopard frog reintroduction is provided through a competitive state wildlife grant awarded to WDFW from USFWS’s Wildlife and Sport Fish Restoration program.