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Amphibians
According to BBC
News, the United Nations biodiversity agency IUCN believes
it would cost over $400 million to save the world's amphibians
(frogs, toads, and salamanders) from extinction. About one
third of the world's amphibians are at a high risk of extinction.
The IUCN cited six causes of the global declines including
infectious disease (mainly chytridiomycosis),
climate change, chemical
contamination, invasive species,
over-harvest, and habitat
loss and degradation.
The situation in Rocky
Mountain National Park reflects, to some extent, the global
situation. Of the five
species of amphibians documented from the park, one, the
leopard frog (Rana pipiens) , is extirpated (apparently
locally extinct) and the boreal toad (Bufo boreas)
has declined dramatically in the last decade. What is the
cause? We have no firm answers. Researchers
from the U.S. Geological Survey working in the park have
documented chytridiomycosis in many of the park's amphibians,
including boreal toads. From the above list of threats,
some indicators of climate change and chemical contamination
have been documented from the park, but not directly linked
to effects on amphibians. The last three threats on the list
are far less likely to be directly affecting park amphibians.
Based on amphibian declines linked to the
apparently recent appearance of chytridiomycosis
globally, researchers have been trying to determine the disease's
origin. One recent, intriguing hypothesis suggests
it
may have been spread as a result of use of African frogs in
human pregnancy tests in the 1930s and 1940s. Dr. Rick
Speare of James Cooke University in Townsville, Australia
has found the oldest known evidence of chytridiomycosis
in South African clawed frog (the species used in the pregnancy
tests) in museum specimens and proposed the theory which is
currently being discussed in scientific circles. Whatever
the source, this deadly disease appears to be a major contributor
to mortality of amphibians in Rocky Mountain National Park
and globally.
Rocky Mountain National Park is currently
working closely with the USGS Amphibian Research and Monitoring
Initiative to keep tabs on amphibians in the park in relation
to other amphibian populations along the Continental Divide
including Glacier, Yellowstone, and Grand Teton National Parks.
Research includes investigations into the demographic characteristics
of populations such as survival; genetic structure of the
wood frog population in the Kawuneeche Valley; and close monitoring
of boreal toad populations throughout the park.
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Please click on captions for larger figures
and pictures
Leopard
frogs are thought to be extirpated from the park
Boreal toads are on the
decline in the park
Researchers
are monitoring wood frog populations in the Kawuneeche Valley
Photos courtesy of Rocky Mountain National
Park.
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