High Rates of Shiny Cowbird Parasitism on The Brown-and-Yellow Marshbird Select for Complementary Host Defenses

The condor

Myriam E. Mermoz¹ 

关键词: brood parasitism;    cowbird nest searches;    egg rejection;    enemy recognition;    host defenses;    nest attention;   

DOI  :  10.1525/cond.2013.120146

学科分类：动物科学

来源: Central Ornithology Publication Office

【 摘 要 】

Abstract. Hosts of brood parasites may have not developed antiparasitic defenses either because host and parasite are recently sympatric or because costs of potential defenses outweigh their benefits. We studied antiparasitic defenses of the Brown-and-yellow Marshbird (Pseudoleistes virescens) against the Shiny Cowbird (Molothrus bonariensis), evaluating recognition and aggression toward female and male Shiny Cowbirds, estimating rates of rejection of cowbird eggs of different colors, and testing the effect of the size of parasite eggs on host rejection. We also observed and video-recorded host nests to estimate hosts' nest attentiveness, frequency of cowbird visits, and interactions between marshbirds and cowbirds. When marshbirds were faced with dummy models, they attacked first and more intensively those of cowbirds (both sexes) than those of a control species. Frequency of egg ejection increased as differences between cowbird and spotted marshbird eggs increased (immaculate > intermediate > spotted), ...

【 授权许可】

CC BY