Planet's Amphibians "Just Can't Keep Up" With Multiple Threats - 1/3 Facing Extinction

[hatrack]

Despite surviving the age of dinosaurs and numerous bouts of severe climate change, amphibians are not keeping pace with the current rate of global change, reports a new study published in the journal Bioscience.

"We know that there are various causes for amphibian population declines, including UV-B light exposure, habitat loss, pesticide pollution, infections and other issues," said Andrew Blaustein, author of the study and a professor of zoology at Oregon State University. "But looked at in a different way, it's not just that there are threats and pressures amphibians have to deal with. There have always been threats, and these have been some of the most adaptive and successful vertebrate animals on Earth. They were around before the dinosaurs, have lived in periods with very different climates, and continued to thrive while many other species went extinct. But right now, they just can't keep up."

More than a third of the world's 5,743 known species of amphibians are threatened, while 168 species are believed to have gone extinct in recent years. Blaustein says that amphibians are especially at risk "because their physiology and complex life cycle often exposes them to a wider range of environmental changes than other species must face – they have permeable skin, live on both land and water, their eggs have no shells."

"Historically, amphibians were adept at evolving to deal with new conditions," Blaustein said. "What they are doing is showing us just how rapid and unprecedented are the environmental changes under way. Many other species will also be unable to evolve fast enough to deal with these changes. Because of their unique characteristics, the amphibians are just the first to go."

EDIT

http://news.mongabay.com/2007/0430-amphibians.html

[iconoclastic cat]

1. All part of God's plan, I'm sure. nt

[blindpig]

2. More here:

There are several hypothesized causes for recent amphibian declines. Here we break them down into two major categories based on Collins and Storfer’s (2003) review. The first category include factors general to the overall biodiversity crisis: habitat destruction, alteration and fragmentation (Fisher and Shaffer 1996, Davidson et al. 2001, Marsh and Trenham 2001), introduced species (Vredenburg 2004, Kats and Ferrer 2003) and over-exploitation (Jennings and Hayes 1985, Lannoo et al. 1994). For these threats, we have a better understanding of the ecological mechanisms underlying declines (Collins and Storfer 2003). However, amphibians have also declined in relatively ‘pristine’ environments (Wake 1991, Crump et al. 1992, Lips 2000). The more complex and elusive mechanisms potentially underlying declines include climate change (Pounds et al. 1999, Kiesecker et al. 2001, Carey and Alexander 2003), increased UV-B radiation, chemical contaminants (Hayes et al. 2002, Blaustein et al. 2003), emerging infectious diseases (Daszak et al. 2003; see AmphibiaWeb's global distribution map of chytrid) and deformities (or malformations). The underlying mechanisms behind these factors are complex and they may be working synergistically with more straight forward factors, such as habitat destruction and introduced species, to exacerbate declines (Kiesecker et al. 2001, Blaustein and Kiesecker 2002). Researchers are finding that there is not a single overarching cause for global declines, instead all of these factors are threatening amphibian populations to a greater or lesser extent. Here we briefly summarize current amphibian decline research addressing how all of these threats are adversely affecting amphibians.

http://amphibiaweb.org/declines/declines.html

say goodbye

[kestrel91316]

3. At this rate, the only life on earth to survive man's reign will be

cockroaches, rats, and microbes.