Heat stress impacts the relationship between cognition and anti-predator behaviour in wild magpies

Climate change is predicted to increase incidents of heat stress, which is known to impair cognitive performance. Associative learning, a highly conserved cognitive trait, is thought to underpin anti-predator behaviour, though direct empirical evidence is lacking from natural populations. If true, this would imply that environmental stressors, such as heat stress, may affect the ability of wild animals to respond to predators. However, the effect of heat stress on the link between associative learning and anti-predator behaviour has received limited empirical attention. Using wild Western Australian magpies (Gymnorhina tibicen dorsalis), we investigated 1) whether associative learning predicts anti-predator behaviour, and 2) whether this relationship is influenced by heat stress. We predicted that birds with better associative learning performance would respond more strongly to a simulated predator threat, but that this relationship would be significantly weakened by heat stress. Consistent with our first prediction, we found that individuals with higher associative learning performance were more responsive to the simulated predator threat. Contrary to our second prediction, heat stress did not disrupt the relationship between associative learning performance and vigilance. Rather, individuals with better associative learning produced more alarm calls and took longer to return to normal behaviour under heat stress. These findings provide some of the first empirical support for the hypothesized link between associative learning and anti-predator behaviour in a wild bird population. Furthermore, they suggest that associative learning may facilitate behavioural adaptation to challenging environmental conditions by enabling individuals to integrate cues such as temperature into context-appropriate anti-predator responses.