These authors contributed equally to this work.
Parental Effort in Relation to Structural Plumage Coloration in the Mountain Bluebird (Sialia currucoides)
Article first published online: 15 AUG 2007
Volume 113, Issue 9, pages 838–846, September 2007
How to Cite
Balenger, S. L., Scott Johnson, L., Brubaker, J. L. and Ostlind, E. (2007), Parental Effort in Relation to Structural Plumage Coloration in the Mountain Bluebird (Sialia currucoides). Ethology, 113: 838–846. doi: 10.1111/j.1439-0310.2007.01386.x
- Issue published online: 15 AUG 2007
- Article first published online: 15 AUG 2007
- Received: November 20, 2006 Initial acceptance: January 19, 2007 Final acceptance: April 12, 2007 (S.A. Foster)
Indicator models of sexual selection suggest that costly ornaments signal reliable information regarding an individual's quality to potential mates. In species that produce altricial offspring, the amount of parental care provided by both males and females can impact reproductive success. The Good Parent Hypothesis proposes that ornamentation in biparental species can act as an honest signal of parental ability to potential mates. We tested this hypothesis using the mountain bluebird (Sialia currucoides), a sexually dichromatic, socially monogamous species in which both sexes have structurally based ornamental plumage coloration. A male's plumage color predicted neither the rate at which it provisioned nestlings nor brood growth rate. The same was true for females. We also found no indication of assortative mating by color or body condition. Feeding rates within pairs were positively correlated, which we suggest may be due to pairs responding similarly to the perceived needs of nestlings or to local area prey availability. In sum, our results do not support the Good Parent Hypothesis as an explanation for the evolution of ornamental plumage color in mountain bluebirds. We suggest alternative hypotheses for the evolution of ornamental plumage color in this species.