Abstract
Biparental care is common in birds with the allocation of effort being highly variable between the sexes. In most songbird species, the female typically provides the most care in the breeding cycle with both parents providing care when provisioning young. Food provisioning should be directly related to offspring quality; however, the relative influence each parent has on offspring quality has rarely been assessed at the nest level. Consequently, we were interested in assessing the relative influenence male and femae provisioning has on one measurement of offspring quality, nestling mass, in the black-throated blue wabler Dendroica caerulescens. Over a six year period 2003-2008, we collected information on a average nestling mass per brood on day 6 of the nestling cycle and parental provisioning rates on day 7 of the nestling cycle from 182 brood nests on three different study plots. We found that average nestling mass was directly related to male provisioning rate, while it was not related to female provisioning rate. On the other hand, estimated biomass provisioned was some indication that parental influence on average nestling mass was dependent on the other parent's provisoning rate, suggesting that parents work in concert to influence nestling quality.
Keywords
nestling mass,
songbird,
offspring quality,
migratory
Citation
Stodola, Kirk W.; Linder, Eric T.; Buehler, David A.; Franzreb, Kathleen E.; Kim, Daniel H.; Cooper, Robert J. 2010. Relative influence of male and female care in determining nestling mass in a migratory songbird. Journal of Avian Biology 41(5):515-522.