Chemicals In The Environment

Archive for the ‘Chemicals in the Environment’ Category

Good news for endangered California frogs

Sunday, February 5th, 2012

We were happy to learn that a few days ago the California Fish and Game Commission voted unanimously to designate two species of native yellow legged frogs inhabiting high-elevation lakes in the Sierra Nevada and Southern California mountain ranges as threatened and endangered species under the state’s Endangered Species Act. The commission acted after the Center for Biological Diversity filed a petition outlining the decline.

photo courtesy National Park Service. Department of the Interior

According to the Center, the population of Sierra Yellow legged frogs has decreased by 75% in recent decades. Reading about these frogs, we were struck by how they are a symbol of the challenges that frogs face worldwide. But they aren’t facing one challenge—they seem to be facing almost all of them:

Introduction of nonnative species: Stocking of nonnative trout in high-elevation Sierra lakes has been the main cause of the species’ decline. The trout eat tadpoles and juvenile frogs and alter the food web of the aquatic ecosystems on which the native frogs depend. The Department is recommending no trout stocking in the state without a fish management plan, and no further stocking of trout in areas that would conflict with protecting yellow-legged frogs.

Pesticides: Recent research has linked pesticides that drift from agricultural areas in the Central Valley to declines of native amphibians in the Sierra Nevada. Pesticides and other pollutants can directly kill frogs and also act as environmental stressors that render amphibians more susceptible to diseases, including a chytrid fungus that has recently ravaged many yellow-legged frog populations.

Loss and degradation of habitat: Grazing, logging, water diversions, off-road vehicles and recreational activity are allowed in frog habitat.

Climate change: Climate change has brought warmer temperatures, decreases in runoff, shifts in winter precipitation in the Sierra from snow to rain, and habitat changes that are rendering frog populations more vulnerable to drought-related extinction events.

A recent settlement agreement with the Center for Biological Diversity, which will also speed protection decisions for 756 other species, requires the U.S. Fish and Wildlife Service in 2013 to make a decision about whether to add the Sierra frog to the federal endangered list.

See the Center for Biological Diversity for more information about these frogs and about the other endangered species they are working to protect.

Tags: California Fish and Game Commission, Center for Biological Diversity, chytrid fungus, climate change amphibians, climate change frogs, endangered frogs habitat loss, mountain yellow-legged frogs, pesticides frogs, pesticides yellow legged frogs, Sierra Nevada yellow-legged frog, Southern California yellow legged frog, threat nonnative species frogs, U.S. Fish and Wildlife Service frogs, yellow legged frogs endangered, yellow legged frogs Endangered Species Act
Posted in Amphibian habitat loss, Chemicals in the Environment, Climate change and frogs, Climate change and the Environment, Deforestation and amphibians, Deforestation and frogs, Frog Conservation, Uncategorized, chytrid fungus, frogs as bioindicators, habitat loss | No Comments »

What’s Really Scary: A World without Bats

Sunday, October 30th, 2011

It’s almost Halloween and what animal is more associated with this spooky holiday than any other? The answer isn’t frogs, it’s bats.

Unlike frogs, however, which seem to have lots of human friends and supporters, bats have few. Most people find them pretty creepy. They’re associated with vampires and other scary things.

I learned about bats many years ago when I lived in Ohio. When I visited friends’ homes out in the country, bats would often emerge at sunset, and they were quite beautiful, flying up into the sky. I also watched a swarm of bats emerge at sunset from Carlsbad Canyons in New Mexico (see video below), a daily natural spectacle.

Did these bats make a beeline for the humans so they could bite them and suck their blood? No. They ignored us humans completely, focused instead on finding some tastier prey—mosquitoes and other insects.

Unfortunately bats seem to be sharing the fate of frogs and bees—they are vanishing because of a mysterious fungal disease. As Sandra Steingrabber writes in Raising Elijah: Protecting Children in an Age of Environmental Crisis: “The possible contribution of pesticides and climate change to the bats’ malady is a topic of discussion among field biologists—as is the synchronous vanishings of fungal-afflicted honeybees and frogs.”

In 2006 scientists found hundreds of dead bats inside several caves across the country—all had white muzzles, the result of a fungus. Bats with this white-nose disease were subsequently found in 115 different caves from Tennessee to Quebec. The fungus grows on the exposed skin of a hibernating bat and causes the bat to wake up, behave strangely, and burn up its fat reserves, thus starving to death.

The disease has claimed the lives of a million bats across 19 states. More than half of the bat species in the United States are in severe decline or are listed as endangered.

A World Without Bats

So what would the world be like without bats?

Imagine being swarmed by insects and bitten by mosquitoes from head to toe. Imagine pests wiping out agriculture across the country, causing produce prices to go up.

If the decline of bats continues these scary scenarios could be our reality.

We need these spooky, fast-flying mammals that can eat 1,200 insects in an hour, protecting us from the West Nile Virus and other deadly diseases.*

So this Halloween, amid all the Batman and vampire costumes, don’t forget that bats are pretty amazing—and important—animals that need our help. One way you can help bats is to build a bat house. Here’s some information from the National Wildlife Federation.

Here’s a video of Mexican free-tail bats emerging at sunset at Carlsbad Caverns in New Mexico, to eat their evening meal of millions of insects:

For more information: