Tyler Abbott, Ryan Moehring and Kim Vincent share some good news for the Endangered Wyoming Toad. The Laramie Plains of south-central Wyoming aren’t exactly what you would call prime amphibian habitat. At an elevation of more than 7,000 feet, the sun beats down ruthlessly on this arid highland. Blazing hot summers yield only to subzero winters. There are few trees for cover and the wind is as relentless as the endless hordes of hungry mosquitos.
Yet this inhospitable land is the unlikely – and last – sanctuary of North America’s most endangered amphibian, the Wyoming toad.
Once abundant on Wyoming’s Laramie Plains, the species experienced an unexplained population crash in the middle 1970s, and the last-remaining wild Wyoming toad population survives in a tiny oasis at Mortenson Lake National Wildlife Refuge, which was established in 1993 specifically to protect the small toad. Here the toad lives in isolation—hidden from view in the shortgrass prairie communities within the river basin, in the flood plain, and in the ponds, oxbows, wetland and riparian habitats on the refuge. No good can befall the tiny toad if it wanders too far from this secluded haven.
Visual encounter surveys suggest that in that haven, though, the toad is thriving.
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| Enclosures help keep endangered Wyoming tadpoles safe. Photos by USFWS |
During the 2015 field season, surveys documented 1,268 toads, the highest number found since their decline in the late 1970s. Surveys also documented a naturally produced egg mass, the first sign of reproduction in the wild since 1999.
This is happy news for a species that was presumed extinct from 1985 to 1987, and even now is considered extinct in the wild by the International Union for Conservation of Nature. As recently as 2011, the annual survey counted only one toad in the wild.
But in 2012, Team Toad (the Service, zoos, Wyoming Game and Fish Department, University of Wyoming and other academia, private landowners and many other conservation organizations) decided to try a new approach. We launched a pilot study that used reptaria – a type of release pen for amphibians. The concept is simple: provide tadpoles with a safe, enclosed environment to grow and acclimate in the aquatic habitat in which you intend to introduce them. We provide them with cover and food until they morph into toadlets. Once they are large enough, we transfer them to terrestrial reptaria that keep the toadlets in and predators out. We keep them protected as long as we can and release the toadlets into the wild right before they should begin looking for places to hibernate. The theory is that at this advanced growth stage, the toads stand a better chance of survival.
The results speak for themselves, and this week the Service and Wyoming Game and Fish Department released the Final Recovery Plan for the Wyoming toad.
While much remains to be done in conserving North America’s most endangered amphibian — the deadly chytrid fungus remains a major threat — there is hope that the tide is turning. Ten years ago, very few people knew that Wyoming toads existed at all. Now, at the end of a hot day chasing toads under the brutal Laramie sun, biologists can cool off with a Wyoming Toad IPA, a craft beer from a local brewery. However brief, it is a refreshing reprieve from the daunting work of trying to bring back a species from the brink of extinction.