Parental Provisioning in Melospiza melodia (Song Sparrows)

We investigated the division of parental care to nestlings in Melospiza melodia melodia (an eastern subspecies of Song Sparrow) by examining parental provisioning rates (number of trips/nestling/h) over two consecutive broods. Song Sparrows are a territorial, socially monogamous passerine with pairs raising up to three broods together over the breeding season. We obtained provisioning rate data for nine pairs over a total of 12 broods (7 first broods, 5 second broods) on at least some of days (stages) 2–3, 5–6, and 8–9 of the nestling period. Of these, we obtained provisioning data over all three nestling stages for six different pairs (five first broods, one second brood). Males and females provisioned young at similar rates throughout the nestling period. Provisioning rates did not differ significantly between first and second broods, but increased significantly as the nestlings aged, reflecting the increased offspring feeding demands. Offspring provisioning does appear to be truly biparental in this eastern subspecies of Song Sparrow.