Breeding site fidelity and seasonal variation in breeding effort in a tropical migrant songbird

• Ano de defesa: 2023
• Autor(a) principal: Guimarães, Aléxia Paula Rodrigues Sandim
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Universidade Federal de Viçosa; Manejo e Conservação de Ecossistemas Naturais e Agrários
• Palavras-chave em Português: Pássaros; Reprodução; Migração; Habitat; Conservação da Biodiversidade
• Link de acesso: https://locus.ufv.br//handle/123456789/32075; https://doi.org/10.47328/ufvcaf.2023.007

This dissertation investigates two intriguing aspects of birds’ reproductive ecology: breeding site fidelity and seasonal variation in breeding effort. For that, we used the lined seedeater (Sporophila lineola), a tropical migrant songbird, as a model species. The first chapter explores breeding site fidelity, a common strategy among migratory birds, and its potential association with prior breeding success. Utilizing data from a monitored population of lined seedeaters during seven breeding seasons, we tested the hypothesis of a "win-stay, lose-change" by measuring the distance between nests built in subsequent seasons and the success of the last nest in the previous season. We found no significant difference in nest distances based on reproductive success, suggesting that breeding site fidelity in lined seedeaters is not primarily determined by prior breeding success but rather by other factors, such as habitat quality and predictability. The second chapter focuses on seasonal variation in breeding effort, an aspect of a species' life history influenced by multiple factors. We observed a significant reduction in both clutch size and mean egg volume per clutch as the breeding season progressed. Notably, female body size did not influence the reproductive variables tested. These findings provide insights into the strategies migratory birds employ to optimize reproductive success within a breeding season. Overall, this research emphasizes the importance of considering habitat characteristics in the study of breeding site fidelity in migratory birds. Additionally, the investigation contributes to our broader knowledge of bird life history strategies and the ecological factors influencing reproductive output within a breeding season. Keywords: Breeding site fidelity. Migratory birds. Reproductive success. Habitat quality. Seasonal variation. Reproductive effort.