United States - June 12, 2025 Columbia National Wildlife Refuge, Washington – In a breakthrough moment for conservation, endangered northern leopard frogs reared in captivity have survived their first winter in the wild. Biologists confirmed the survival of several frogs released last August into the refuge. This success comes despite the presence of invasive American bullfrogs, a major threat that has nearly eradicated the native species. The frogs were raised at the Oregon Zoo and Northwest Trek Wildlife Park. Their survival marks a critical milestone for recovery efforts. “This is great news,” said a zoo official. “We care for these frogs until they’re ready for release, but they wouldn't make it without efforts to control invasive bullfrogs.” The bullfrogs, introduced from the eastern U.S., are the largest frog species in North America. Weighing over a pound, they prey on native species and spread disease. “This is a major milestone for our effort to save northern leopard frogs,” said a conservation manager involved in the program. “It proves collaboration can make a real difference.” Still, experts warn the work is far from over. “Reintroductions are challenging,” said a herpetologist from the Washington Department of Fish and Wildlife. “But these survivors offer hope.” Efforts to assess predator threats and control bullfrog populations are ongoing. “This shows how destructive invasive species can be,” the herpetologist added. “But it also shows how targeted action can help restore balance.” Northern leopard frogs were once common across North America. In Washington, they’ve been listed as endangered since 1999, with only one known population left. The recovery program involves a coalition of zoos, wildlife agencies, and universities. Funding was provided through a competitive state wildlife grant.