Severe Perkinsea infections may be responsible for a significant number of frog die-offs
A emerging disease has been identified as another possible cause for amphibian die-offs, according to the U.S. Geological Survey. Scientists already know that chytridiomycosis and the ranavirus are linked to frog population declines worldwide.
A far-ranging study of wood frogs have found that the bog-breeding amphibians could be vulnerable to global warming at the southern edge of their range, and that the population could shift northward, similar to many other species.
But the research, covering more than 740 wood frog populations in 27 different areas, also showed some nuance in the response to climate change. That makes it hard to determine which species and which populations are in danger of declining or disappearing, according to researcher David Miller, assistant professor of wildlife population ecology at Penn State.Local and regional precipitation trends are nearly as important as temperature in determining the fate of many animals, he explained, and that’s especially true with moisture-sensitive creatures such as amphibians. Continue reading “How will global warming affect wood frogs?”→
FRISCO — Along with the deadly chytrid fungus that has been wiping out frogs and salamanders for a few decades, there’s a new emergent threat to amphibians.
Researchers from the UK and Spain are tracking severe disease and mass deaths in many amphibian species in the mountains of northern Spain, where common midwife toads, common toads and alpine newts are taking the biggest hit, showing levels of population collapse which could ultimately prove catastrophic to amphibian communities and their ecosystems. Continue reading “Biodiversity: Amphibians now facing huge viral threat”→
Court settlement may ultimately help protect endangered amphibians
By Summit Voice
FRISCO — In a classic case of government do-nothingism, federal agencies have known for years that pesticides are killing rare California frogs — but have failed to act to protect the amphibians from the poisons.
But that should change soon, as a federal court this week approved a deal that requires the U.S. Fish and Wildlife Service to prepare detailed environmental studies on the effects of seven common pesticides: Glyphosate, malathion, simazine, pendimethalin, permethrin, methomyl and myclobutanil.
Biologist ‘shocked’ to see morphological changes in vertebrates
By Summit Voice
SUMMIT COUNTY — Exposure to sub-lethal doses of a widely used weed killer caused tadpoles to grow abnormally large tales, according to University of Pittsburgh biologist Rick Relyea, who has been studying ecotoxicology and ecology for two decades.
Relyea has conducted extensive research on the toxicity of Roundup® to amphibians. Monsanto has challenged some of the studies and Relyea has responded to the criticism on this website.
In his latest study, Relyea set up large outdoor water tanks that contained many of the components of natural wetlands. Some tanks contained caged predators, which emit chemicals that naturally induce changes in tadpole morphology (such as larger tails to better escape predators). After adding tadpoles to each tank, he exposed them to a range of Roundup® concentrations. After 3 weeks, the tadpoles were removed from the tanks.
“It was not surprising to see that the smell of predators in the water induced larger tadpole tails,” Relyea said. “That is a normal, adaptive response. What shocked us was that the Roundup® induced the same changes. Moreover, the combination of predators and Roundup® caused the tail changes to be twice as large.” Continue reading “Popular weedkiller causes deformities in amphibians”→