Toad fungus tracked to South Africa
SUMMIT COUNTY – Emergence of a chytrid fungus that infects the skin of boreal toads in Summit County and other amphibians has been traced back to South Africa, said Colorado Division of Wildlife biologist Kevin Rogers.Amphibians rely on their highly porous skin to regulate their environment, and the fungus somehow interferes with that delicate chemical balance.
Rogers said that researchers have tracked the fungus back to South Africa, where it was reported in the 1940s. At the time, he said, aquarium frogs were being shipped from South Africa around the world, possibly spreading the fungus from continent to continent.He described the fungus as sweeping wavelike across different geographical regions, reaching Colorado in the 1970s. In the subsequent decades, amphibian populations in this state and the rest of the Southern Rockies declined at startling rates. Populations at more than 80 percent of previously known boreal toad breeding sites in the region have vanished, according to the Colorado Division of Wildlife. Locally, the crash was reflected when a boreal toad population near the Henderson Mine near Ute Pass in northern Summit County declined dramatically in the mid-1990s.
The decline has not yet been as dramatic in the Northern Rockies, where boreal toads are still common in Idaho, for example.Based on what is known so far about chytrid fungus, Rogers said the best hope for conserving and recovering the species may be to try and discover whether some of the toads that survived the initial chytrid wave have some genetic resistance to the fungus.”Some populations have lingered. Maybe there’s some resistance,” he said, explaining that the state is experimenting with younger toads at an aquatic research facility in Alamosa.
Other observations from the Henderson Mine indicate toads in a pond with elevated levels of copper survived the fungal wave. In one experiment, the state is treating toad habitat with copper sulfate, Rogers said.Vail, Colorado
Support Local Journalism
If you don't follow the rules, your comment may be deleted.
User Legend: Moderator Trusted User