COS 62-3 - Consequences of weather and migration characteristics on reproductive success in black-bellied plovers

Background/Question/Methods

Weather conditions experienced by birds can influence their migration decision-making and strategy both within the migration season and across seasons. Additionally, decision-making during migration may influence subsequent reproductive success. Shorebirds are in decline worldwide, and are sensitive to landscape and climate change. The black-bellied plover (Pluvialis squatarola) often associates with mixed migratory shorebird flocks and is a good model system for studies of shorebird migration. Our objectives were to test for effects of winter and spring weather conditions on reproductive success through migration decision-making in black-bellied plovers and compare effects of weather conditions during winter, migration and breeding seasons on migration strategy and reproductive success to identify critical stages of the annual cycle and inform targeted monitoring and conservation. To meet these objectives, we tracked 24 black-bellied plovers from wintering areas in coastal Louisiana and Texas to breeding areas in the Alaskan and Canadian Arctic. We summarized migration strategies and weather conditions experienced by each individual throughout the winter, spring, and summer seasons. We analyzed these data using a Bayesian hierarchical model which connected generalized linear mixed models linking (1) winter and spring weather with migration metrics and (2) migration metrics and breeding season weather with reproductive success.

Results/Conclusions

We found negative relationships between two migration metrics, migration duration and number of stopovers, and reproductive success, but not substantial relationships between breeding season weather variables and reproductive success. Further, we found negative relationships between winter temperature, spring environmental conditions during migration, and both migration duration and number of stopovers. We found positive relationships between storms during migration and migration duration, and between winter precipitation and number of stopovers. Our results show that reproductive success was influenced by migration strategy, which itself was explained by weather conditions from winter and spring. Increased monitoring of winter and stopover conditions, which are currently under-studied, is critical for shorebird conservation planning as the climate and landscape change.