by Sophia Escudero
Humboldt County, with its streams and rivers, undeveloped wild spaces, and above-average amount of rain, is an ideal habitat for amphibians.
The Pacific tree frog, also known as the Pacific chorus frog, is the most common local frog. Its habitat spans from Northern California to Alaska, and it makes its home in ponds, rivers, forests, grasslands, and even urban settings. The distinctive “ribbit, ribbit” song of the Pacific tree frog can be heard clearly in spring as the male of the species attempts to attract a mate. However, they can be harder to spot than to hear.
“They seem to blend with their background,” said adjunct professor Brian Hudgens of the Cal Poly Humboldt wildlife department. “It’s not as fast as a chameleon, but they do. If you put a green one against a brown background for a couple days and then come back, it will turn brown.”
Less audible is the California red-legged frog, which gives its call underwater and can be found in slow-moving water and ponds. The California red-legged frog has a celebrity history, having been named the California state amphibian and starring in a Mark Twain short story, “The Celebrated Jumping Frog of Calaveras County.” This frog is a threatened species due to habitat loss, despite efforts being made by the state of California and the federal government.
Another protected frog is the foothill yellow-legged frog, which is a species of concern. The yellow-legged frog lives in streams and, although they vary in coloration, can be identified by their rough skin and habit of jumping into moving water. Their historic range extends from Oregon to Baja California.
“The foothill yellow-legged frogs are breeding now, and you might be able to see egg masses attached to rocks and cobble near the shallow edges of our local rivers,” Hudgens said. “I actually would appreciate hearing if any of your readers see an egg mass and want to pass along the location and any photos.”
While both the California red-legged frog and the foothill yellow-legged frog are listed as threatened or endangered species in the state of California, the Humboldt populations are thriving.
“Most of the places where it lives, or where its historic range covers, are the foothills on the edge of the Central Valley,” Hudgens said of the yellow-legged frog. “And those are areas that are under a lot of developmental pressure, a lot of agricultural pressure, and the rivers and streams around here don’t have the same kind of pressure.”
To help out local frogs, the most important thing you can do is speak out against the development of their natural habitats. Humboldt is a haven for native frog species, and protecting their habitats protects them. When you are in a frog breeding ground, such as a river or pond, it’s important to keep an eye out for eggs and tadpoles underfoot. Washing shoes and swim equipment before and after going to the river can help stop the spread of disease to different populations.
You can create a habitat for frogs in your own backyard. Providing any size pond or standing water can encourage frogs to lay eggs, especially if you live near an existing frog habitat. Hudgens recommends allowing the pond to dry out fully once a year in order to discourage invasive bullfrogs, which prey on native species and compete with them for resources. Bullfrogs take two years to fully mature, while native frogs reach adulthood in a matter of months.
“If you’ve got a stream running through your backyard, maintaining a nice cobble area will really help out the yellow-legged frogs,” Hudgens said. “If you’re in an area with bullfrogs, trying to keep them out is probably the biggest thing we can do for all of our amphibians.”
Hi Sophia, local biologist here. Just wanted to point out we do not have California red-legged frog (Rana draytonii) in Humboldt. We only have Northern red-legged frog (Rana aurora) which are a species of special concern but are not listed.