Little blue frog makes a big splash in Moses Lake rare-species survey

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A rare blue Northern Leopard Frog, discovered by Washington Fish and Wildlife biologists in August 2019. (Photo: Sean Dougherty)

MOSES LAKE — There’s one special variety of frog that’s rare in Washington state, but even rarer when it comes in a different color.

There are only between 700 and 1,500 Northern Leopard Frogs in the state, all of them residing in North Potholes Reservoir near Moses Lake. When biologists and volunteers with the Washington Department of Fish and Wildlife surveyed the frog population in August, they came across an uncommon example of the species.

“Typically, Northern Leopard Frogs are either green or brown,” says Fish and Wildlife biologist Sean Dougherty, based in the department’s Ephrata office. “We have both varieties, and green is the recessive, brown is dominant … During the course, of the survey, we stumbled across a blue frog.”

The trait is so seldom seen, Dougherty says, that he initially doubted whether the frog was part of the species he’d set out to study.

“At first, I wasn’t sure that it was the right kind of frog. It was just bizarre. We took some pictures, like ‘Gee whiz, that’s really cool,’ and then shared it amongst some colleagues, and they were like, Wow, that is really cool! And that’s surprisingly rare.'”

Northern Leopard Frogs are an endangered species in the state, and a species of concern for federal wildlife agencies. The blue frog’s mutation is unusual and exciting, but its chances of passing on the trait are low — Dougherty says 90 percent of the frogs die before they reach sexual maturity.