Influência do nidoparasitismo por chupim (Molothrus bonariensis) sobre a alimentação de filhotes em ninhos de sabiá-barranco (Turdus leucomelas)

• Autor(a) principal: Ferneda, Rafaela Vitti
• Data de Publicação: 2022
• Tipo de documento: Trabalho de conclusão de curso
• Idioma: por
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://hdl.handle.net/11449/216147
• topic: Turdus leucomelas; Molothrus bonariensis; Nest parasitism; Parental behavior; Parental discrimination; Aves; Parasitismo; Comportamento parental; Discriminação parental; Parasitismo de ninho; Turdidae; Aves comportamento

About 1% of bird species are considered brood parasites. As an evolutionary response to losses caused by parasites, host species present antiparasitism strategies, which involve the detection and rejection of parasitic eggs and nestlings or the abandonment of the parasitized nest. However, little is known about the complex capacity of detection and rejection of offspring of parasitic species by hosts in Neotropical birds. The aim of this study was to identify a possible discrimination of the nestlings of the brood parasite shiny cowbird (Molothrus bonariensis) in feeding events by the thrush (Turdus leucomelas). More specifically, I tested the hypotheses that (1) the behavior of nestlings before being fed differs between the cowbird and the thrush species; (2) thrush nestlings are fed more often than cowbird nestlings; (3) the time it takes the adult to select the nestling to be fed is longer for the cowbird nestlings; and (4) the frequency with which thrush nestlings begs for food is higher in parasitized nests. Data were collected from video recordings made between 2015 and 2017 of nests found in the campus of the São Paulo State University “Júlio de Mesquita Filho” (UNESP), in Rio Claro-SP. Cowbirds were fed faster and more frequently than thrush nestlings, and induced an increase in the frequency of feeding visits by the parents, which was higher in parasitized nests. In addition, there were differences in the behavior of the two species before being fed: cowbirds begged more than thrush nestlings, in which the headraising behavior predominated. There was no difference in the behavior of the thrush in parasitized and non-parasitized nests. Results suggest that there is no clear distinction between the parasitic and their own nestlings by the parent thrushes.