Sex differences in canary (Serinus canaria) provisioning rules

I investigated how male and female captive canaries (Serinus canaria) decide to divide resources among their nestlings. Specifically, I examined whether parents partitioned food in proportion to the size-related competitive prowess of their young or their postural begging intensity. Females responded to both aspects of nestling behaviour. They allocated food in relation to the height attained by offspring during begging as well as the intensity of their postural display. When the brood was especially hungry, mothers additionally favoured offspring at the front of the nest, nearest their perch position. By contrast, males allocated food only in relation to competitive ability, simply by preferring offspring that reached higher during begging. I compare these findings with previous work on other species and discuss why females changed their provisioning rules in relation to brood hunger.