Reply #2: More here: [View All]

[blindpig]

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