Friday, April 16, 2010

Mountain Yellow-Legged Frog returns (maybe)

(See photos below story. The adult frog photo is courtesy of the USGS, Town Crier staff took the other photos.)

The mountain yellow-legged frog eggs were planted in a local stream yesterday. If nature cooperates a new population of the indigenous endangered frog will be established in its native habitat.

A multi-agency team planted three clutches, about 500 to 600 eggs in the stream. Adam Backlin and Liz Gallegos, both the of U.S. Geological Survey, carefully removed the clutches from their Tupperware home in a plastic bucket and placed them in a screened box in a larger screened box to protect the eggs as much as possible from natural predators.

Several mountain yellow-legged frogs were collected from the wild. Scientists have been trying to breed this population since 2006. This winter, they hibernated 31 of the frogs. This mimicked the frog’s natural mountain winters, according to Becca Fenwick, director of the James San Jacinto Mountains Reserve.

“A group of us came up with the idea to duplicate their winter,” Backlin said. The scientists will keep a close eye on the egg clutches.

Tadpoles should develop and begin swimming about the pools in early summer. Their natural predators are raccoons, hawks and especially garter snakes. The tadpole stage will last through next summer. Just before winter the tadpoles will metamorphosize into small frogs.

“Then they are immediately punished with their first winter,” Backline added.

In addition, the research team will reintroduce a large number of tadpoles about the same time as these eggs transform to tadpoles. One reason for testing both frog stages is determining whether the egg release or waiting until the tadpole stage would be the more successful reintroduction technique.

“This is an amazing first step in the recovery program for this wonderful frog, and we are looking forward to having the frogs here for a long time to come,” Fenwick said.

The team works at the San Diego Zoo’s Institute for Conservation Research. Besides the U.S.G.S. biologists, other participating agencies included the U.S. Fish and Wildlife Service, the Forest Service, the state Fish and Game Department and the University of California James Reserve.

Adam Backlin and Liz Gallegos, U.S. Geological Survey biologists transfer the egg clutches to a smaller container.

Backlin begins the entry process. He dips the water from the stream into the eggs compartments.

Notice the highly specialized and expensive scientific equipment used during the placement of the eggs into the stream compartments.

To assure that the eggs are placed properly and with delicacy, the entire re-introduction event is recorded.

Ken Bohn and Shea Johnson of the San Diego Zoo cover every action, while Stan (right) for a local daily paper waits for the right moment.

A happy adult frog, wait patiently for two years.


  1. They look like eyeballs! Hopefully the hatching is successful and these little guys can help rebuild the yellow-leg frog population.

    JP, do you have any photos of what the adult frogs look like?

  2. Yes, I'll post it in the blog above, but at the end. It's courtesy of the U.S. G.S.

    by the way, when asked why biologists would work for the USGS rather than FWS, the response was, "They're regulators, we get to do research."


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