Translator Disclaimer
1 April 2002 SHORT- AND LONG-TERM EFFECTS OF MALE-LIKE CONCENTRATIONS OF TESTOSTERONE ON FEMALE EUROPEAN STARLINGS (STURNUS VULGARIS)
Author Affiliations +
Abstract

European Starlings (Sturnus vulgaris) exhibit marked sex differences in behavior during spring. Song activity, nest-box occupation, the carrying of green nesting materials into a nest hole (typical mate-attraction behaviors), and aggression occur much more frequently in males who also have higher testosterone (T)-levels than females. Here, we examined whether male-like concentrations of T would activate these behaviors in female starlings. We treated females with implants that were either empty (C-females) or packed with T (T-females) during late December. Although elevated T-levels significantly increased song activity in females, the proportion of time spent singing was still much lower than in males. T-treatment in females also failed to induce singing behavior in the nest box, a typical male mate-attraction behavior. Those results suggest both activational and organizational effects of T on singing. Nest-box occupation, carrying of green nesting material into a nest hole, and aggressive behavior were not activated by elevated T-levels, indicating that sex differences in these behaviors are probably based on early organizational effects of steroid hormones. We also evaluated effects of increased T-concentrations on some physiological, morphological, and immunological parameters. T-treatment strongly suppressed tail feather regrowth after experimental plucking, and also delayed onset of molt of wing feathers and slowed its progress. T-implantation caused color of the bill to change from black to yellow, but did not affect body mass. Immune function was determined by using two indirect measures: blood composition (haematocrit and buffy coat values) and indications of infections. Although haematocrit and buffy coat values did not differ between C- and T-females, T-females were significantly more infected with Staphylococcus aureus than C-females at the end of the experiment.

Elke De Ridder, Rianne Pinxten, Veerle Mees, and Marcel Eens "SHORT- AND LONG-TERM EFFECTS OF MALE-LIKE CONCENTRATIONS OF TESTOSTERONE ON FEMALE EUROPEAN STARLINGS (STURNUS VULGARIS)," The Auk 119(2), 487-497, (1 April 2002). https://doi.org/10.1642/0004-8038(2002)119[0487:SALTEO]2.0.CO;2
Received: 24 January 2001; Accepted: 14 January 2002; Published: 1 April 2002
JOURNAL ARTICLE
11 PAGES


SHARE
ARTICLE IMPACT
RIGHTS & PERMISSIONS
Get copyright permission
Back to Top