To determine how quickly species must move to new ranges to outpace climate change, UW researchers used previous work by Lawler that reveals areas with climates needed by each species, along with how fast climate change might occur based on 10 global climate models and a mid-high greenhouse gas emission scenario developed by the UN Intergovernmental Panel on Climate Change.
The UW researchers coupled how swiftly a species is able to disperse across the landscape with how often its members make such a move. In this case, the scientists assumed animals dispersed once a generation.
It's understandable, for example, that a mouse might not get too far because of its size. But if there are many generations born each a year, then that mouse is on the move regularly compared to a mammal that stays several years with its parents in one place before being old enough to reproduce and strike out for new territory.
Western Hemisphere primates, for example, take several years before they are sexually mature. That contributes to their low-dispersal rate and is one reason they look especially vulnerable to climate change, Schloss said. Another reason is that the territory with suitable climate is expected to shrink and so to reach the new areas animals in the tropics must generally go farther than in mountainous regions, where animals can more quickly move to a different elevation and a climate that suits them.
Those factors mean that nearly all the hemisphere's primates will experience severe reductions in their ranges, Schloss said, on average about 75 percent. At the same time species with high dispersal rates that face slower-paced climate change are expected to expand their ranges.
"Our figures are a fairly conservative even optimistic view of what could happen because our approach assumes that animals always go in the direction needed to avoid c
|Contact: Sandra Hines|
University of Washington