Increasing the perceived predation risk changes parental care in female but not in male Great Tits Parus major

In birds, little is known about how the presence of predators alters parental food distribution decisions among nestlings. We found that experimentally increasing perceived predation risk changed parental care in female but not in male Great Tits Parus major. Females fed the lightest and average nestlings at similar rates under control conditions when predation risk was not manipulated but ignored the lightest nestling under increased perceived predation risk. Moreover, females reduced the duration of nest visits greatly after encountering a model predator, suggesting that the perception of predators may facilitate brood reduction mechanisms.