Figure 2.

The potential effects of changes in temperature on predator–prey interactions, based on fish as prey, and fish or an endotherm (e.g. a bird) as predators, based on a scenario of future global warming. Downwards and upwards arrows indicate a decrease and an increase, respectively; while a ≈ sign indicates no significant change. At high temperatures, prey conditions (growth and metabolism) increase and so does the escape performance, also because of the direct effect of temperature. Temperature has similar positive effects on fish predator attacks (via direct effects and because of decreased body conditions). In addition, because of their higher routine activity and higher hunger level (due to higher metabolism), the frequency of predator–prey interactions increases (though they may decline at high temperatures that exceed acclimation temperatures; see main text). Temperature has little effect on performance and hunger level on endotherms (compared to the effect on ectotherms), and therefore predator success rate is expected to decrease at high temperature because of the positive effects of temperature on prey escape performance.