Reproductive Success of a Neotropical Migratory Songbird in Response to a Changing Climate

Climate change is of rising concern especially due to how and if this changing climate affects individual species and their fitness. Migratory species, especially long-distance migrants, are ideal models for exploring the relationship between warming temperatures on temperate breeding grounds and decreased precipitation on tropical wintering areas. Few studies have long term data sets to observe species-specific assessments of fitness in relation to changing precipitation and temperature patterns, and those that have assessed these relationships show inconsistent results. We analyzed long-term data of a neo-tropical migratory songbird (Protonotaria citrea) to assess the potential relationships between indices of reproductive success and variation in tropical rainfall and breeding season temperature. We found that the species tended to have longer breeding seasons in years with increased annual temperatures and increased rates of double brooding with increased precipitation in the wintering grounds. Prothonotary warblers had smaller first clutches in stronger El Nino years, though this relationship was weak. Breeding ground precipitation was not correlated with any index of reproductive success. Results suggest that a combination of breeding ground temperature and wintering grounds precipitation play a role in the timing of spring breeding and the prevalence of double brooding, respectively. These findings are important for predicting the sensitivity of long-distance migratory birds to changes in climate, and provides additional evidence for carry over effects between portions of the annual cycle in migratory songbirds.https://scholarscompass.vcu.edu/uresposters/1210/thumbnail.jp