Washington officials warn African clawed frogs, "one of the worst invasive species on earth," are eating local animals
An invasive species — one that can survive in drought, freezing weather and even outer space — is consuming and competing with native species in western Washington, officials are warning. Scientists have spotted African clawed frogs in Issaquah, Lacey and Bothell, KING5 reported.
The frogs were initially brought into the United States to be used in pregnancy tests and later became pets, said state wildlife scientist Max Lambert.
Although Washington made it illegal to own them, some still do. Some who have decided not to keep the frogs released them into ponds and streams. As officials began looking into the issue, they discovered hundreds of frogs.
"These are considered one of the worst invasive species on earth," Lambert said. "They'll eat a lot of native insects, which are good forage food for our fishes and our amphibians, they will eat tadpoles of our native salamanders, and they'll eat fish. We looked at some of their stomach contents — and they're full of baby fish."
African clawed frogs have olive or brown skin, often with blotches or spots, and they don't have eyelids, tongues, or vocal sacs, according to state wildlife officials. Their front feet are unwebbed while their back feet are fully webbed with black, sharp claws.
"The primary use of these claws is likely to shred food, which could be a decaying carcass, another frog species, fish, bird, snail, or anything else they can fit in their mouth," state officials say. "In fact, their claws help them eat other frogs and fish that are bigger than them because they can tear their prey into smaller pieces."
People working to restore salmon populations fear the frogs will infringe on that progress.
Since Trout Unlimited began trapping in January, the organization has caught about 300 frogs, Rebecca Lavier said. Around half of those have been found in the past few weeks. They believe it's just a fraction of the population.
According to the Washington Department of Fish and Wildllife, African clawed frogs "harm native ecosystems by competing with and preying on native species: and they also have the potential to introduce harmful pathogens that hurt native fish and amphibian populations."
"African clawed frogs have a long life span, an extended breeding season, and are prolific reproducers," the agency says. "They can even survive severe drought and freezing conditions!"
In fact, they can even survive in outer space. Four female African clawed frogs were launched aboard space shuttle Endeavour in September 1992 for a study that showed frogs can reproduce in zero gravity. Once in orbit, the frogs were injected with a hormone that caused egg production.