A key biological trait driving different responses to temperature change among consumers and resources is body velocity the speed at which an animal moves. Cold-blooded animals, for example, tend to move faster as their body temperature increases. The biologists predict that one of the primary impacts of global warming will be increasing the amount of time and speed with which organisms move around a landscape and thus encounter and interact with one another.
Specifically, the researchers say, the effects of climatic warming will be determined by the ways in which predators seek their prey by moving around the landscape in search of mobile prey (active-capture), by remaining stationary and waiting for moving prey (sit-and-wait) or by moving around in search of immobile prey (grazing) as well as by whether interacting predatorprey species are both cold-blooded, both warm-blooded or one of each.
Because of the effect of temperature on body velocity, biologists predict that encounter rates between predators and prey will increase with rising temperatures if the foraging strategy is active-capture (both predator and prey moving through the landscape), as with an eagle hunting a fish. However, if both species respond to temperature in identical ways, these changes may not lead to significant shifts in their interactions.
With a sit-and-wait strategy, often used by snakes and lizards, the effects of temperature change would arise primarily via the moving prey species, potentially creating a very strong asymmetry between predator and prey. In this case, the asymmetry may profoundly alter the nature of the interaction, so that the two species have much higher or lower abundances and may no longer be able to coexist in the feeding relationship without one or both going extinct.
Similarly, increasing temperatures are likely to have significant impacts on interactions between warm-bl
|Contact: Stuart Wolpert|
University of California - Los Angeles