Behavioral Ecology and Sociobiology

, Volume 49, Issue 1, pp 24–30

Experimental evidence of a testosterone-induced shift from paternal to mating behaviour in a facultatively polygynous songbird

  • E. De Ridder
  • R. Pinxten
  • M. Eens
Original Article

DOI: 10.1007/s002650000266

Cite this article as:
De Ridder, E., Pinxten, R. & Eens, M. Behav Ecol Sociobiol (2000) 49: 24. doi:10.1007/s002650000266

Abstract 

Previous studies have suggested that testosterone (T) profiles of male birds reflect a trade-off between mate attraction behaviours (requiring high T levels) and parental care activities (requiring low T levels). In this study, we experimentally elevated T levels of monogamous males in the facultatively polygynous European starling (Sturnus vulgaris), and compared mate attraction and paternal behaviour of T-treated males with those of controls (C-males). T-males significantly reduced their participation in incubation and fed nestlings significantly less often than C-males. Females paired to T-treated males did not compensate for their mate’s lower paternal effort. The observed reduction in a male’s investment in incubating the eggs was accompanied by an increased investment in typical female-attracting behaviours: T-males spent a significantly higher proportion of their time singing to attract additional females. They also occupied more additional nestboxes than C-males, although the differences just failed to be significant, and carried significantly more green nesting materials into an additional nestbox (a behaviour previously shown to serve a courtship function). T-males also behaved significantly more aggressively than C-males. During the nestling period, the frequency of mate-attracting behaviours by T-treated and control males no longer differed significantly. Despite the reduced paternal effort by T-males and the lack of compensation behaviour by females, hatching and breeding success did not differ significantly between T- and C-pairs.

Keywords TestosteroneSexual selectionParental investmentMate attractionSturnus vulgaris

Copyright information

© Springer-Verlag Berlin Heidelberg 2000

Authors and Affiliations

  • E. De Ridder
    • 1
  • R. Pinxten
    • 1
  • M. Eens
    • 1
  1. 1.Department of Biology, University of Antwerp, U.I.A., Universiteitsplein 1, 2610 Wilrijk, Belgium e-mail: elkedr@uia.ua.ac.be Tel.: +32-3-8202285, Fax: +32-3-8202271BE