La Tour du Valat

Institut de recherche pour la conservation des zones humides méditerranéennes

Titre :	Honesty in host-parasite communication signals: the case for begging by fledgling brown-headed cowbirds Molothrus ater
Auteurs :	M. E. Hauber, Auteur ; C. K. Ramsey, Auteur
Type de document :	Article
Dans :	Journal of Avian Biology (34(4) DEC 2003)
Article en page(s) :	339-344
Langues:	Anglais
Résumé :	Nestling parasites typically beg more intensively than do host nestlings yet these exaggerated displays are also honest in that they are modulated by hunger and age. We hypothesized that honesty was also maintained in the food solicitation behaviors of fledgling brood parasites because the benefits and costs of their begging displays are similar to those of nestling parasites. Begging displays of hand-reared 14-32 days old brown-headed cowbirds Molothrus ater that had experimentally manipulated nutritional needs were recorded to analyze variation in the peak frequency, duration, and rate of fledglings' begging bouts. Peak frequency of bouts decreased with greater age and was lower for females. Bout rate was greater with increasing hunger levels of fledgling parasites but did not vary with age. Consistent and predictable variation of acoustic begging displays with age, sex, and hunger-level indicates honesty in host-parasite communication systems through conveying truthful information about the many possible needs of parasitic fledglings.

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