Agonistic carotenoid signalling in male red-collared widowbirds: aggression related to the colour signal of both the territory owner and model intruder

Citation
Sr. Pryke et al., Agonistic carotenoid signalling in male red-collared widowbirds: aggression related to the colour signal of both the territory owner and model intruder, ANIM BEHAV, 62, 2001, pp. 695-704
Citations number
54
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Animal Sciences","Neurosciences & Behavoir
Journal title
ANIMAL BEHAVIOUR
ISSN journal
0003-3472 → ACNP
Volume
62
Year of publication
2001
Part
4
Pages
695 - 704
Database
ISI
SICI code
0003-3472(200110)62:<695:ACSIMR>2.0.ZU;2-2
Abstract
Carotenoid colour displays are widely assumed to be honest indicators of in dividual health or quality, primarily in mate attraction. Here we show that sexually dimorphic carotenoid ornamentation functions as an agonistic sign al in male red-collared widowbirds, Euplectes ardens. Mounted mate models d iffering (within natural limits) in the intensity of carotenoid signalling were presented to wild resident males as simulated intruders, perched or ma de to 'fly' across the territory with the elongated tail folded or keeled. Perched mounts were generally ignored, and stronger aggression towards 'fly ing' models with a keeled tail (i.e. as in courtship display) than a folded tail suggests the tail display is used to assess the intention of intrudin g males. Territory owners were less aggressive towards models with intense collar display, suggesting that carotenoid coloration functions as a badge of status in this species. The level of aggressive response was also relate d to the resident's own badge in that males with larger, redder collars res ponded more aggressively to the models. In addition, males with a larger co llar signal defended larger territories and spent less time in territory de fence. Apart from the collar size and 'redness', no other morphological var iable predicted the aggressive response of territorial males. Given the pre viously demonstrated insignificance of the collar in female mate choice, we suggest that the nuptial carotenoid coloration is an honest signal of domi nance or fighting ability, sexually selected through male contest competiti on over territories. (C) 2001 The Association for the Study of Animal Behav iour.