Plasticity in foraging behaviour as a possible response to climate change

Climate change is regarded as one of the major concerns of the 21st Century, with mean temperatures expected to increase by about 3 degrees C over the next 100 years. Species responses to climate change are not consistent, with some species apparently able to respond more quickly than others, thus producing changes in community structure. One increasingly common observation is that species at lower trophic levels respond more quickly to change in climate than species at higher levels. This can result in, for example, the timing of a predator's peak food requirements being separated in time from the point at which their prey is most available. It has been suggested that this creates an additional risk for the persistence of species at high trophic levels as the climate alters; there is an alternative possibility - that predators may change their diets in response to changing prey availability. Models of diet choice make several predictions, for example they suggest that whether a predator includes a secondary prey into its diet depends on the availability of the primary prey and not on characteristics of the secondary prey. By switching between one prey type and another, a predator population may be able to persist in a particular location longer than they would otherwise. Using a simple demonstration model we show that this idea is theoretically plausible.