Climate change and amphibian declines

[Extract] Evidence that climate change is currently affecting life on earth has become overwhelming in the last few years. Although some continue to question the link between global warming and human activity, the rate of current trends in temperature shifts is vastly different from past global climate change events. For example, in lower elevation cloud forests in the Andes, the warming trend experienced from the 1970s to the present is 18 times faster than at the end of the last ice age (Bush et al. 2004). Species of plants and animals in many different taxonomic groups and regions of the world are already responding to warming, by shifting their ranges uphill or towards the poles and tracking cooler environments (Walther et al. 2002). The timing of seasonal cycles, such as flowering in plants and migration in birds, has also been shifting with the changing climate (Root et al. 2003). Spawning dates and breeding migrations in a number of amphibian species have already become significantly earlier (Root et al. 2003). Although these changes might appear trivial, they do alter the composition and dynamics of communities, with complex and unpredictable outcomes. For example, in Britain, newts are now arriving much earlier at breeding ponds, allowing their predatory larvae to be much larger by the time frogs arrive. This may be detrimental for frog species that now deposit their eggs and tadpoles into pools full of hungry newt larvae (Beebee 1995). Along with changes in species’ ranges and phenology, current models predict a great loss of species in the future due to a warmer and more extreme climate (Thomas et al. 2004). In fact, climate change may already be causing extinctions