SEXUALLY SELECTED VIGILANCE BEHAVIOR OF THE GREY PARTRIDGE IS AFFECTED BY PLASMA ANDROGEN LEVELS

In the grey partridge, Perdix perdix, vigilance and calling activity a re two sex-dimorphic behaviours that are critical for mate choice. To ascertain whether circulating levels of testosterone directly affect v igilance (i.e. the occurrence of upright alert posture), we compared v igilance scores of testosterone-implanted versus control males both du ring the normal activity of the flock and after the passage of a rapto r silhouette; in the latter case, the calling activity was also record ed. Hormone-treated males were more vigilant than controls in both exp erimental situations. Vigilance was correlated with calling rate. Test osterone seems to act as a link, relating conspicuous behaviours invol ved in sexual selection to male quality and physical condition, becaus e of the costs of having high levels of both signalling and androgens. (C) 1997 The Association for the Study of Animal Behaviour.