Recent deaths of endangered boreal toads in one of the largest remaining populations in the southern Rocky Mountains have been linked to a chytrid fungus identified last year as being responsible for amphibian die-offs in Central America and Australia, according to pathologists at the USGS National Wildlife Health Center in Madison, Wis.
Sick and dying toads in the Colorado population were first discovered in May of 1999 by Colorado Division of Wildlife researchers, who have been intensively studying the animals for the last 5 years. Since May, dead toads have been found every month at the site, which is on private lands west of Denver. USGS researchers said they have identified chytrid fungus in many of the dead and living toads they examined from the site in 1999. Live toads show few clinical signs of the disease, but some may appear weak, lethargic and reluctant to flee at the approach of humans.
Dr. D. Earl Green, a USGS wildlife pathologist, microscopically examined many of the dead toads and identified myriads of minute chytrid fungi in the skin of the abdomen and toes of the toads. His microscopic identification of this fungus is being confirmed in collaborative work by Dr. Joyce Longcore, a world-renowned chytrid expert at the University of Maine. In addition, USGS researchers will continue to work closely with researchers from the Colorado Division of Wildlife to monitor further die-offs.
Secretary of the Interior Bruce Babbitt calls these recent die-offs of
boreal toads a "poignant reminder" that amphibian populations in this
country and in many other parts of the world are undergoing severe,
unexplained declines. In the past decade, the international scientific
community has increasingly expressed concern over global population
declines in all amphibian groups and on many continents. These losses
are now well documented and have occurred in a wide range of habitats,
including remote and pristine areas in O
Contact: Paul Slota
United States Geological Survey