It’s one of the most ancient frog species on Earth — as old as the dinosaurs.
It’s also one of the longest-lived — up to 20 years.
But the coastal tailed frog is most famous for its long….um, tail. I mean, its prominent….er, copulatory organ.
“It’s essentially a penis,” says The Nature Conservancy’s Larry Serpa, an aquatic ecologist who first discovered the coastal tailed frog living in the Garcia River Forest, 21 miles south of its known range on the California Pacific coast.. “Of the 5,000 or so species of frogs and toads in the world, there are only two species that have one.”
But why stick out?
Most frogs release their eggs and sperm into the water, like fish. But that reproductive method won’t work in the cold, clear, fast moving streams like those found in the Garcia River, which would wash the eggs and sperm away. So the coastal tailed frog instead wields its extended cloaca (that’s what scientists like to call it) to fertilize females internally.
Being so-well adapted to its environment makes the coastal tailed frog extremely sensitive to changes in its habitat. That’s why Larry Serpa started searching for it in the Garcia River Forest. And when he found it, he knew it was a watershed moment for the ecosystem.
“It was a long shot, because the tailed frog was not known to have ever been this far south,” said Serpa, who has been working on Conservancy biodiversity surveys in the 23,780-acre reserve since 2007. “Past damage to watersheds has seriously impacted these guys, but conditions have been looking up in this watershed. If the frog was ever here before, I thought ‘Why not now?’”
Serpa turned over nearly 1,000 slippery creek rocks before he found a coastal tailed frog. In fact, he found two at once: a tailed male frog and a wide-mouthed tadpole.
Finding the pair among the rocks in the Garcia is a testament to the health of a watershed that’s long been on the frontlines of restoration and sustainable forestry efforts by the Conservancy, The Conservation Fund, local landowners and other environmental groups.
Once an old-growth forest filled with redwoods and Douglas firs, the Garcia River Forest was intensively logged by timber companies in the 19th century. Yet the watershed began to truly suffer with the advent of truck and tractor logging in the 1950s. Poorly planned timber roads, carved across California’s north coast, unleashed tons of soil into the water, creating wider, shallower and warmer streams.
“Imagine you are a little tadpole hanging out under this rock among the holes and cobbles,” said Jennifer Carah, director of the Conservancy’s water monitoring program in the Garcia River Forest. “Now if someone dumps a truck full of sand and mud into the river upstream of your spot, it would bury you alive. You’d have nowhere to eat, nowhere to live, and nothing to breathe.”
Community activists along with state and federal regulators have been working to stop that landslide for the last 25 years. In 1993, the Garcia River became the first watershed listed for sediment pollution under the Federal Clean Water Act.
The pace and scale of restoration and conservation picked up in 2004 when The Conservation Fund bought the Garcia River Forest, funded in part by the sale of a conservation easement to The Conservancy. Together, the partners have since implemented sustainable forestry and watershed restoration practices that could permanently preserve and protect much of the watershed and the wildlife that live there.
The coastal tailed frog is very long-lived and breathes through its skin as a tadpole, qualities that make it not only a very good indicator of improved water quality in the Garcia, but also of the potential for restoration there of other cold-water adapted species like salmon and trout.
“The fact that the frogs exist on timber harvesting holdings is surprising,” said Hartwell Welsh, a wildlife biologist and the region’s foremost expert on the species.
Hartwell believes the frog is the best biological indicator for ecosystem health in the redwood biospheres. “In old-growth redwood forests that are still intact, you don’t have to turn over 1,000 rocks to find them. You can just turn over one.”
That’s good news for Larry Serpa, who’s been busy turning over rocks since his original discovery in 2009. So far he’s found three frogs, nine tadpoles, and six metamorphs-frogs with tadpole tails.
Whenever a coastal tailed frog whips out its, um, equipment, the watershed is making progress.
“Conditions keep getting better and better, ” Serpa quips enthusiastically. “The frog population is going to increase more and more.”
First image: The coastal tailed frog’s genitalia measures up to a quarter of its body length. Image credit: Larry Serpa/The Nature Conservancy. Second image: Map of the Garcia River Forest, a 23, 780-acre reserve on the Pacific coast.