November 23, 2010

 

FINAL RELEASE OF TADPOLES FOR 2010

 

Endangered tadpoles were released into a stream near Idyllwild, Calif., today with hopes that the Southern California population of the mountain yellow-legged frog Rana muscosa will thrive again. This is the second release of tadpoles into the same stream here on the property. The release was done in collaboration with partners including the U.S. Geological Survey, U.S. Forest Service, U.S. Fish and Wildlife Service, the California Department of Fish and Game, and the San Diego Zoo Institute for Conservation Research. The initial reintroduction effort of this species occurred in April 2010 when about 500 eggs were released into the stream in hopes of successful hatching. The tadpoles from that release of eggs are so small that it has been difficult for scientists to determine how many survived.

The first-ever tadpole reintroduction for the species occurred in August. By “head starting” the tadpoles, partners hoped to increase survival in the wild. These tadpoles were kept in warmer temperatures and had more food available to them before their initial release than they would have had in the wild. The release was conducted using both caged and free-swimming tadpoles. Eighteen tadpoles were released immediately into the stream while another 18 were put into a cage in the stream; the cage protected the tadpoles from predators and also allowed researchers to feed them. Each grouping was tagged with a different color marker. All 18 tadpoles in the cage survived the three-month period of reintroduction into the stream and were about 50 to 60 millimeters long (1 to 2½ inches) when they were released from the cage today. In one location the water levels had risen higher than the cage walls allowing the tadpoles to swim free on Sunday. The tadpoles were photographed, measured, and samples were taken to assess their heath. In the spring, scientists will go back to the stream and count the tadpoles to determine which of the release methods was most successful.

 “The experiments will help us to determine the most successful way to re-populate Southern California creeks with the highly endangered mountain yellow-legged frog,” said Frank Santana, research technician for the San Diego Zoo Institute for Conservation Research, where the tadpoles were bred. “The initial success that we have had with tadpole survival is very encouraging, but the real test will be how many tadpoles survived through the harsh winter.”

The creek is frequently monitored and some of the free-swimming tadpoles from the August release have been spotted during these efforts. “When I survey the creek I am constantly on the lookout for the tadpoles,” said Becca Fenwick, director of the James San Jacinto Mountains Reserve. “I am excited for the day when I come upon my first full-grown mountain yellow-legged frog, a species that once thrived throughout Southern California.”

Globally, amphibians are on the decline because of habitat loss, effects of climate change, pesticide residue, introduction of nonnative species, and the spread of a deadly pathogen called the chytrid fungus. The mountain yellow-legged frog is one of three frogs or toads on the federal endangered species list in Southern California and has recently been proposed for listing under the California Endangered Species Act. Today, only a small wild population of less than 200 adult mountain yellow-legged frogs can be found in the San Gabriel, San Bernardino, and San Jacinto mountains.

The San Diego Zoo Institute for Conservation Research was the first to breed the mountain yellow-legged frog outside of its native habitat.  Historically, scientists have had great difficulty breeding frogs in laboratories. This year, Zoo scientists discovered that the frogs’ breeding behaviors increased in the lab after the frogs were chilled to temperatures that resembled their high mountain stream environment.  Scientists hope the second year of breeding will result in an even higher fertility rate. The Zoo’s breeding program, in conjunction with its partners, began after a wildlife biologist with the San Bernardino National Forest noticed declining creek water levels in Dark Canyon in Riverside County in 2006. The Fish and Wildlife Service’s salvage effort started the next day. Recovered tadpoles were taken to the San Diego Zoo Institute for Conservation Research, where they metamorphosed into frogs.

 

 

Photos:

Top: 2 tadpoles in the holding tank, prior to data collection

Middle left: Tadpoles being meausred to quantify growth

Middle right: Samples being taken to assess health by Frank Santana

Bottom: Final release of tadpoles into the stream, by Franks Santana

 

(photos by R.Fenwick)

 

 

 

 

 

 

 

 

 

 

May 3rd, 2010

 

Underwater Camera Installed In Creek

 

On Wednesday the 28th, we deployed an underwater camera outside the middle cage. It is a SeaMaster SuperMini Underwater Video Camera, both color and black white images are possible, and it is equipped with and IR camera and light source so we will be able to see at night as well. We also have two handheld digital cameras (Pentax Optio WS80) attached to the outside of two of the cages, they are waterproof an so require no houseing. They are setup so that they take a picture every 30 minutes, and we can make timelapse movies from these images.

 

We are hoping to observe the frog eggs hatching very soon on both types of cameras. Once the tadpoles are swimming in the stream we will be looking for a location that they frequent so that the video camera can be moved to that location. Below is a still image from the webcam that is placed in the stream, please click on it to be taken to the page for this camera. The image on the camera page is refreshed every five seconds, and the one below will refresh when you refesh the page.

 

The second image below is a 3 minuite movie of the real time images from the webcam that was taken on May 4th. If you would like more recent movies of the eggs please email us.

 

 

 

 

April 16th, 2010

 

Mountain Yellow-legged Frogs Reintroduced to Wild

 

The endangered mountain yellow-legged frog will take a major step in its recovery this week when, for the first time, scientists reintroduce its eggs to its former habitat. This reintroduction will occur at University of California Riverside’s James San Jacinto Mountains Reserve, part of the University of California Natural Reserve System, and will be done in collaboration with the U.S. Geological Survey, U.S. Forest Service, U.S. Fish and Wildlife Service, and the San Diego Zoo’s Institute for Conservation Research. Once common throughout much of southern California, the mountain yellow-legged frog has been decreasing in numbers since the 1970s due to what scientists call the “perfect storm” that is affecting frog populations around the globe -- decreasing habitat, increasing pollution and invasive species, the spread of the deadly chytrid fungus and the effects of climate change. Today, only a small wild population of less than 200 individuals can be found in the San Gabriel, San Bernardino, and San Jacinto Mountains.

 

In 2006, scientists collected mountain yellow-legged frog tadpoles from the remaining wild populations in the San Jacinto Mountains and took them to the San Diego Zoo’s Institute for Conservation Research where, for the first time, specialists were able to establish a captive breeding program for the species. This year’s reproductive season at the Zoo has been so successful that scientists have decided to attempt a reintroduction into the wild.

 

There are 61 mountain yellow-legged frogs at the San Diego Zoo’s Institute for Conservation Research. Scientists attempted to spur breeding in January by putting half of that population into a cooler that mimicked high mountain winter conditions. The chill caused the frogs to hibernate. About two weeks ago the frogs were taken out of the coolers and began displaying breeding behaviors within a few days. “Three months ago the San Diego Zoo started an experimental procedure of chilling these frogs to see how it would effect breeding. It has been wildly successful and as a result today we can reintroduce about 500 eggs into the San Jacinto Mountains” said Jeff Lemm Research Coordinator for the San Diego Zoo’s Institute for Conservation Research “This is a momentous day – the first reintroduction of these endangered frog eggs ever back into their natural habitat and the San Diego Zoo is thrilled to be a part of it”. They selected the James San Jacinto Mountains Reserve for this reintroduction because it is a protected area with ideal habitats in the species’ former range.

 

The mountain yellow-legged frog is one of three Southern California frog or toad species on the Federal Endangered Species List. Biologists from the USGS will be responsible for the initial phase of the reintroduction, and will be releasing egg masses into deep permanent pools, followed by the additional release of tadpoles later in the year. They will then closely monitor the health and success of the reintroduction. It will take two years for the tadpoles to morph into adults and as they are not a migratory species the frogs will stay in the creek within the bounds of the protected reserve where they can be easily monitored. “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” said Becca Fenwick, Director of the James San Jacinto Mountains Reserve.

 

For more information please contact Adam Backlin, Ecologist for the USGS; (714) 508 4702, abacklin@usgs.gov, or Dani Dodge Medlin, San Diego Zoo’s Public Relations Representative; (619) 685 3291. Jane Hendron Division Chief, Public Affairs; (760) 431 9440. Photo and video of the release will be made available Friday by the San Diego Zoo.

 

USGS Press Release

Press-Enterprise

Idyllwild Town Crier

San Diego 6 CW

KPBS, San Diego

10News San Diego

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