No evidence for kin recognition in a passerine bird.

Abstract

Theory predicts that individuals behave altruistically towards their relatives. Hence, some form of kin recognition is useful for individuals to optimize their behaviour. In species displaying bi-parental care and subject to extra-pair matings, kin recognition theoretically allows cuckolded fathers to reduce their parental investment, and thus optimize their fitness, but whether this is possible remains unclear in birds. This study investigates the ability of male sparrows to recognize their own chicks, using a large cross-foster experiment, parental care as an indicator and House Sparrows (Passer domesticus) as a model organism. We cross-fostered chicks after hatching, and then expected that fathers would show a decrease in their parental efforts when tending to a clutch of unrelated offspring. However, there was no significant effect of relatedness on provisioning rates. This suggests that sparrows may not be capable of kin recognition, or at least do not display kin discrimination despite its apparent evolutionary advantage.