Naturwissenschaften

, Volume 96, Issue 10, pp 1177–1184

Melanin-based coloration covaries with ovary size in an age-specific manner in the barn owl

ORIGINAL PAPER

DOI: 10.1007/s00114-009-0579-9

Cite this article as:
Roulin, A. Naturwissenschaften (2009) 96: 1177. doi:10.1007/s00114-009-0579-9

Abstract

While the adaptive function of black eumelanin-based coloration is relatively well known, the function of reddish-brown pheomelanin-based coloration is still unclear. Only a few studies have shown or suggested that the degree of reddish-brownness is associated with predator–prey relationships, reproductive parameters, growth rate and immunity. To gain insight into the physiological correlates of melanin-based coloration, I collected barn owl (Tyto alba) cadavers and examined the covariation between this colour trait and ovary size, an organ that increases in size before reproduction. A relationship is expected because melanin-based coloration often covaries with sexual activity. The results showed that reddish-brown juveniles had larger ovaries than whiter juveniles particularly in individuals in poor condition and outside the breeding season, while in birds older than 2 years lightly coloured females had larger ovaries than reddish-brown conspecifics. As barn owls become less reddish-brown between the first and second year of age, the present study suggests that reddish-brown pheomelanic and whitish colorations are associated with juvenile- and adult-specific adaptations, respectively.

Keywords

Barn owlCovariationEumelaninPheomelaninOvary

Copyright information

© Springer-Verlag 2009

Authors and Affiliations

  1. 1.Department of Ecology and Evolution, BiophoreUniversity of LausanneLausanneSwitzerland