Past a gate covered in brambles and down a faint path blocked here and there by fallen trees lies a small pond caked with algae and surrounded by gray willows. By the edge of the pond, Barry Sinervo carefully inserts a cable into the rear of a lifelike pale green gelatin frog. His student, Anna Ringelman, stands by taking notes.
The UC Santa Cruz ecologist has come to study California red-legged frogs. They’re away at the moment, dispersed across campus for the winter. But that doesn’t bother Sinervo. He designed these rubbery agar models, which soak up water and the sun’s warmth just like real amphibians, to test why frogs across California are going extinct. They can stand in for absentee frogs as well as they have for vanished ones.
As real tree frogs begin to chirp in the undergrowth, Sinervo stoops and places the model frog in a juicy spot by the base of a tree. An electronic attachment will monitor its moisture and temperature. “That's a great spot. If I were a frog I'd go in there,” he tells Ringelman. “Just start thinking like a frog, and that’s the experiment.”
Red-legged frogs were common across the state in the 19th century. But hungry gold miners, invasive bullfrogs, urban development and poisonous pesticides have driven them from 70 percent of their range. Now the federally threatened amphibians hold on in scattered pockets — like this small reservoir in UCSC’s Arboretum. By testing what keeps the frogs comfortable in this holdout, Sinervo and Ringelman hope to learn how to preserve their remaining refuges.
Read the full story at UC Santa Cruz Science Notes.
Nicholas Weiler is a graduate student in the UC Santa Cruz Science Communication Program and intern in the UC San Francisco news office.
