<strong><em>By Kevin Zippel, Program Director
Amphibian Ark, Apple Valley, MN</em></strong>

<strong>Amphibians Matter</strong>
Amphibians are an important component of the global ecosystem. In New York State, the biomass of one diminutive salamander species alone is equal to that of all the white-tailed deer. If you think that is impressive, that same salamander species in Virginia has a biomass 7x as great, another salamander species in Japan has a biomass 50x as great, and a frog species in Puerto Rico has a biomass 150x as great. For those of us living in white-tailed deer country, try to imagine 150x as many deer running around and you will start to have some comprehension of the keystone role just one single amphibian species can have in its ecosystem. All of those amphibians can serve as food for predators in their community, and current research is documenting that in areas of the world where amphibians are disappearing, so too are their specialist predators (Karen Lips, pers. com.). Amphibians are also voracious predators themselves, with a single population of cricket frogs, for example, able to consume 5 million invertebrates in one year (Bruce and Christiansen 1976). Many of those invertebrates are pests of our crops and vectors of human disease. Clearly, amphibians play a vital role in nature.

Amphibians are also important indicators of environmental health. The same thin skin that helps them to drink and to breathe also makes them susceptible to pollutants, more so than other tetrapods. For example, consider Atrazine, the most widely used herbicide in the US and probably the world, and a potent endocrine disruptor. At low concentrations of Atrazine--lower than those the USDA says is safe in drinking water and lower than those found at the tap in millions of American homes--male clawed frogs can be chemically sterilized or even turned into females (Hayes et al. 2010). Because of their generally conspicuous presence in the environment and chemical sensitivity relative to other tetrapods, amphibians can be a considered a canary in the coalmine, valuable sentinels for human health concerns.

And amphibians are important contributors to human medicine. All amphibians have poison glands, with species-specific poisons of various potency and structure. Many of those poisons can be refined for use in human medicine. For example, a South American frog has yielded an analgesic that is 200x more potent than morphine without any of the addictive side effects (Spande et al. 1992), and an Australian treefrog produces a peptide that blocks the transmission of HIV across mucous membranes in humans (VanCompernolle 2005). Every time an amphibian species goes extinct, potential treatments to human ailments disappear as well.

<strong>Amphibians Are in Trouble</strong>
An ongoing Global Amphibian Assessment reveals that as many as 158 amphibian species are believed recently extinct, nearly one in three remaining species is currently threatened with extinction, and one in four is so poorly known that they can only be called Data Deficient (IUCN et al. 2010). Amphibians have a higher number of globally threatened species than any other group of organisms except flowering plants and a higher percentage of threatened species than any other group except gymnosperms. Moreover, the rate at which amphibian species are going extinct is now hundreds or thousands of times higher than historic levels (McCallum, 2007; Roelants et al., 2007). This crisis represents the greatest extinction event in the history of amphibians and perhaps the greatest taxon-specific conservation challenge in the history of humanity.
<strong><img class="alignnone size-medium wp-image-1802" title="green_tree_frog" src="http://aecetia.net/gws/aazk/wp-content/uploads/green_tree_frog-300x200.jpg" alt="green_tree_frog" width="300" height="200" /> </strong>

<strong>Green Tree Frog</strong> (<em>Hyla cinerea</em>)
<em>(Photo: Tim Krynak)</em> <strong>
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<strong>Climate Change Among the Threats</strong>
Amphibians face a variety of threats, including, like every other species on the planet, climate change. Climate change is an enigmatic threat for any taxon. Although we know enough about it that we should be seriously concerned, we simply do not know exactly how, when, and to what extent it will manifest, let alone how species might respond. As such, there is inconsistency in how climate change is considered as a threat among experts, although most do now recognize that it is on track to become one of the greatest threats to all life on earth. Compare climate change to a more ‘traditional’ and tangible threat like habitat modification: IUCN Red List assessors consider various forms of habitat modification a threat for 3766 of 6284 amphibian species. On the other hand, only 397 species are currently considered to face the threat “climate change and extreme weather”. By comparison, amphibian chytridiomycosis, for all the attention it has received, is only known to have affected 350 species to date (Fisher et al. 2009, Skerratt et al. 2007). Climate change is something of an enigma and consequently does not receive the attention it deserves, from politicians or amphibian biologists.

Clearly though, some amphibian species are already being impacted. Reproductive activities, in particular, seem dependant on…………

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