“I didn’t know we even had toads in Wyoming” said Padara Thomas, an English major at the University of Wyoming. “I wouldn’t think they could live out here”
Perhaps they can’t.
The Wyoming Toad (Bufo baxteri) has been listed as critically endangered under the Endangered Species Act since 1984 and is listed as “extinct in the wild” by the International Union for Conservation of Nature, an international organization that ranks animals by how threatened the species is.
There are currently 500 Wyoming Toads in captivity in the U.S. and Canada in zoos and federal facilities.
A captive Wyoming Toad at the Saratoga National Fish Hatchery.
The Wyoming Toad is native to the Laramie Plains of southeast Wyoming. The plain sits between the Laramie Mountains to the east and the Medicine Bow mountains to the west.
The original range of the Wyoming Toad is just 2,330km², smaller than the state of Rhode Island, according to the U.S. Fish and Wildlife Service.
Such a small range can be detrimental to a species survival by allowing disease to quickly spread throughout a population, with devastating consequences.
The greatest threat to the Wyoming Toad currently is Chytrid Fungus, which causes lethargy, sluggishness and eventually asphyxiation in most amphibian species. Habitat loss, irrigation, drought and the use of pesticides are also factors in the toads reduced numbers.
Despite being listed as extinct, the Wyoming toad has slowly been making a comeback due to the efforts of breeding programs like the Saratoga National Fish Hatchery’s just north of Saratoga, Wyoming.
David Paddock, a Fish Biologist at the Saratoga National Fish Hatchery,is in charge of the Wyoming Toad breeding program at the facility. The hatchery has 70 adult toads in the breeding program.
Due to the small population size of the Wyoming Toad, choosing which toads will mate is important to prevent inbreeding. “It’s done by a studbook. Our studbook keeper in Omaha will pair them up for which ones will give genetic diversity.” said Paddock
While the hatchery has 70 toads, they don’t breed all of them every year. “We hibernated 21 toads, but we lost two of them so we had 19 Wyoming Toads for breeding this year.” Said Paddock.
Hibernating is done by placing toads into a freezer to trick their bodies into thinking they have experienced winter and when they are thawed out, that mating season is beginning.
A row of tanks containing Wyoming Toads at the Saratoga National Fish Hatchery
Those 19 captive toads generated 3620 tadpoles and 50 toadlets for release this summer in Mortenson Lake National Wildlife Refuge, the protected habitat where every wild Wyoming Toad lives.
Not all of the toads reared in the facility are released “We kept some for numbers purposes.” Said Paddock. Replacing toads killed in the hibernation process or that are growing old is essential to keeping the program going.
Paddock doesn’t take his program’s toads for granted and doesn’t put young toads at risk by hibernating them. “If they are only one (year old) we give them another year to reach maturity. Especially the females.”
Most years there is at least one casualty of the hibernation process at the Saratoga facility.
While Paddock and his team in Saratoga are having success, that is not the case for all programs trying to breed the toads.
Sara Plesuk, Supervisor of Reptiles and Amphibians at the Henry Doorly Zoo and Aquarium and her team in Omaha, Nebraska have 25-30 Wyoming Toads in their breeding program and hibernated 2 pairs for mating but were unable to produce any tadpoles for release into the wild this year. “We had no fertile eggs this year” said Plesuk. “Last year we did release 70 tadpoles.”
Plesuk hopes that next year her zoo’s program will be able to begin contribute tadpoles for introduction into the wild again.
Since the program started in 1995 the Henry Doorly Zoo and Aquarium has produced 2689 Wyoming Toad tadpoles for release into Mortenson Lake National Wildlife Refuge.
Nine other facilities breed the Wyoming Toad for release into the wild:
• Cheyenne Mountain Zoo
• Detroit Zoo
• Kansas City Zoo
• National Mississippi River Museum and Aquarium
• Toledo Zoo
• Como Zoo
• Toronto Zoo
• Red Buttes Environmental Lab (USFWS—Wyoming)
With over one hundred thousand Wyoming Toads released into the wild from all breeding facilities since 1995, Paddock is confident in the system’s ability to produce tadpoles. For him the problem seems to be getting them to thrive once released. “They face so many predators and are so dependent on water, they have it rough.”