Breeding ecology of the mangrove warbler (Dendroica petechia bryanti): Assessing the effects of weather, food abundance and nest depredation

Knowledge on life history traits and on how both biotic and abiotic factors influence reproduction of tropical birds is poor. Here, I describe the breeding biology of the Mangrove Warbler (Dendroica petechia bryanti) from southern Mexico and examine for latitudinal differences in life history traits relative to its migratory relative, the Yellow Warbler (Dendroica petechia). Secondly I examine how rainfall, food abundance and nest depredation influence reproduction and habitat occupancy.; I found that relative to Yellow Warblers there was significant variation in most Mangrove Warbler's life history traits, which provides a convincing case for the role of the tropical environment in shaping the evolution of life history traits of tropical birds.; The idea that rainfall is the most important factor influencing the onset of breeding in tropical birds was not supported. Instead, breeding was timed to coincide with peaks in food abundance, supporting the food availability hypothesis. Similar to temperate zone birds, photoperiod appears to be the main long-term breeding stimuli in Mangrove Warblers, while changes in arthropod abundance may act as cue for adjusting clutch initiation.; Depredation accounted for 65% of nest losses with annual rates changing apparently in relation to changes in climatic conditions and food availability. Daily survival rate of nests did not vary throughout the season, but it was significantly higher during the incubation than the nestling stage, however, the percentage depredated at each stage was similar. Nest depredation rates varied by habitat and were not influenced by human activities. Avian predators were the most important.; Territory vacancies, both natural and experimentally created were reoccupied disproportionately by young birds, supporting the habitat limitation hypothesis. Totally vacant territories were often reoccupied by new pairs, indicating that pairing might be a behaviour that could aid in successful territory takeovers among floaters.; My thesis contributes with new and relevant information about the role the tropical environment plays in influencing reproduction and patterns of habitat occupancy in tropical birds. Because Mangrove Warblers are closely related to Yellow Warblers and because they share many attributes with other tropical insectivorous species, they are ideal for further latitudinal comparative studies.