Resumo

FIORINI, Vanina D.; ASTIE, Andrea A.; TUERO, Diego T.  e  REBOREDA, Juan C.. Reproductive success of shiny cowbird (Molothrus bonariensis) in hosts of different body size. Hornero [online]. 2005, vol.20, n.2, pp.173-182. ISSN 0073-3407.

We analyzed different components of the reproductive success of Shiny Cowbird (Molothrus bonariensis) in three hosts that differ remarkably in body size: the House Wren (Troglodytes musculus), the Creamy-bellied Thrush (Turdus amaurochalinus), and the Chalk-browed Mockingbird (Mimus saturninus). For each host we estimated nest survival, and parasite's egg survival, hatching success and chick survival in successful nests. In Troglodytes musculus and Mimus saturninus nests we also analyzed the association between number of eggs and hatching success of the parasite, and between number of host chicks and chick survival of the parasite. The survival and hatching success of parasite's eggs did not differ between hosts, but chick survival was lower in Turdus amaurochalinus nests. Hatching success was negatively associated with number of eggs in Troglodytes musculus nests but not in those of Mimus saturninus, while chick survival was negatively associated with number of host chicks in Mimus saturninus nests but not in those of Troglodytes musculus. These results, as well as the ones of other studies, show that there is no clear association between the reproductive success of Molothrus bonariensis and the body size of the host and point out the importance of considering other host life history traits in addition to body size.

Palavras-chave : Brood parasitism; Molothrus bonariensis; reproductive success; Shiny Cowbird.

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