The Wyoming toad, now the most endangered amphibian in North America, once flourished in the wetlands and rivers of southeastern Wyoming, say field biologists with the US Fish & Wildlife Service (USFWS).
What once were wetlands now is prairie, and prescribed burning is being used to help the toad recover at Mortenson Lake National Wildlife Refuge, said USWFS Fire Management Officer Felix Valdez.
Valdez is working with federal fish & wildlife managers and biologists, the multi-agency Wyoming Toad Recovery Team and other partners to save the last known population of the Wyoming toad (Bufo baxteri). As part of the effort, nearly 40,000 captive-bred tadpoles and toadlets have been released at the refuge and other safe-harbor sites. Studies are ongoing as to optimum toad habitat and best strategies for releasing captive tadpoles and toadlets.
“This species is especially small for a toad,” said Valdez, explaining that the Wyoming toad averages just over two inches in length.
By the mid-1970s, the population was in decline, he said, “likely due to a combination of insecticide use, changes in climate, agricultural practices, predation, and disease.”
In 1984, the toad was listed under the Endangered Species Act, and in 1993, The Nature Conservancy helped establish the refuge to protect the species.
Valdez was the burn boss for a prescribed burn project in April, 2012 that was designed to give the native toad what it needs to survive: water and warmth. Studies show the Wyoming toad requires pockets of warm, shallow water to breed. Historically, said Valdez, livestock grazing kept refuge rushes (reeds and cattails) in check, allowing plenty of sunlight to warm the waters. Over time, grazing declined. Now, prescribed fires and grazing are needed to keep plant growth from crowding out the toad.
If overgrowth on this high plains prairie is not curtailed, biologists are concerned that Wyoming toads won’t survive in the wild, said Valdez. The collaborative recovery plan, he said, is designed to “achieve self-sustaining populations and ultimately de-list the species.” Another part of the recovery plan includes a captive breeding program at Saratoga National Fish Hatchery in Wyoming and the University of Wyoming’s Red Buttes Biological Lab, as well as various zoos.
To see what’s being done to bring the Wyoming toad back from the brink of extinction, go to http://1.usa.gov/16jQ9IL .
E-mail nature-related news and events to Sacramento Nature Examiner Carol Bogart at email@example.com.