In Cold Blood

Even a big new reserve may not be enough to protect Spain’s threatened lizards, turtles and salamanders from climate change. Warming temperatures could dramatically restrict — or even eliminate – habitat for these cold-blooded “ecotherms,” which can’t regulate their body temperatures like “warm-blood” mammals and birds. The finding suggests conservationists need to take physiological differences into account if they want to create protected areas that can shield sensitive species from climate shifts.

The mountains and valleys around the Spanish capital of Madrid boast some of the country’s richest biodiversity. But the region is being hard-hit by urbanization, and studies predict it will also be reshaped by future shifts in temperature and rainfall. To help address these threats, the Spanish government has proposed ramping up protections for a key regional ecosystem – the Guadarrama Mountain range – by creating a large new reserve.

In the current issue of Animal Conservation, a team led by Pedro Aragon of the National Museum of Natural History in Madrid examine how the new reserve – and a network of nearby protected areas – might help 94 threatened species, including mammals, birds and “herptiles” (reptiles and amphibians). Drawing on climate, soil and land elevation data, they used modeling software to compare maps of current species distributions to how things might look in 2020 and 2100. Overall, they found that climate change shuffled the distribution of many species, but the ecothermic reptiles and amphibians had the hardest time finding safe havens. In particular, they found that the proposed new Guadarrama Mountain reserve “might not favor the persistence of threatened herptiles in the future,” with species losses of up to 22%. The herptiles did a little better in surrounding protected areas.

Those results are in line with other studies suggesting reptiles and amphibians will be especially sensitive to climate change. Warming temperatures can cause amphibians, for instance, to breed earlier or hibernate for shorter periods, and can make them more susceptible to disease. For reptiles, climate change can alter key microhabitats, and may hinder their ability to move and develop eggs. Such processes may hinge on physiological mechanisms sensitive to surrounding temperatures. A key message of their study, the authors say, is that “island-type protected areas with fixed limits are insufficient” to protect sensitive species from climate change. – David Malakoff

Source: Aragón, P., Rodríguez, M., Olalla-Tárraga, M., & Lobo, J. (2010). Predicted impact of climate change on threatened terrestrial vertebrates in central Spain highlights differences between endotherms and ectotherms. Animal Conservation, DOI: 10.1111/j.1469-1795.2009.00343.x

Image © Glenn Nagel |