Extreme temperatures can intensify predator–prey interactions

Extreme temperatures and heatwave events present challenging conditions for wildlife and are increasing in frequency and intensity in many regions due to climate change. High daily temperatures increase physiological stress and cause mortality in susceptible individuals (e.g. from poor health or exposure) but may also drive behavioural changes as individuals seek to thermoregulate (e.g. seeking shelter or water). As daily high temperatures accumulate into heatwave events, the ability of wildlife to tolerate conditions can diminish and exacerbate stress. Although climate change is well known to decouple species interactions, here we examined how extreme conditions may intensify interactions between predators and prey. In particular, we explored whether predators can exploit the thermoregulatory requirements of prey as they increasingly require access to water. We presented evidence from the use of artificial waterpoints by dingoes, Canis dingo , and eastern grey kangaroos, Macropus giganteus , on a wildlife property in Australia's semiarid drylands, asking whether high temperatures and heatwaves alter species behaviour and interactions between them. Both species increasingly accessed waterpoints as daily maximum temperatures increased; however, the degree of co-occurrence at waterpoints increased significantly as the temperatures became extreme and resulted in heatwaves. Not only did waterpoints become increasingly important for both species during heatwaves, but dingo hunting attempts on kangaroos at these times were significantly higher than expected based on the number of days when heat anomalies occurred. Additionally, dingoes relaxed their predisposition to hunt kangaroos in poor body condition, making kangaroo hunting opportunistic during these times. Our findings emphasize the potential for climate change to exacerbate predator–prey interactions, which may have an impact on species persistence if prey is unable to adapt to predators that exploit their thermoregulatory demands. • We studied the influence of heatwaves on kangaroo - dingo interactions at waterpoints. • Kangaroo and dingo activity at waterpoints increased significantly during heatwaves. • High activity rates meant kangaroos were unable to avoid interacting with dingoes. • Kangaroos of all body conditions experienced predation during extreme temperatures.