Publication
Demographic profiles and environmental drivers of variation relate to individual breeding state in a long-lived trans-oceanic migratory seabird, the Manx shearwater
Publisher:
Public Library of Science (PLoS)
Date:
16-12-2021
DOI:
10.1371/JOURNAL.PONE.0260812
Abstract: Understanding the points in a species breeding cycle when they are most vulnerable to environmental fluctuations is key to understanding interannual demography and guiding effective conservation and management. Seabirds represent one of the most threatened groups of birds in the world, and climate change and severe weather is a prominent and increasing threat to this group. We used a multi-state capture-recapture model to examine how the demographic rates of a long-lived trans-oceanic migrant seabird, the Manx shearwater Puffinus puffinus , are influenced by environmental conditions experienced at different stages of the annual breeding cycle and whether these relationships vary with an in idual’s breeding state in the previous year (i.e., successful breeder, failed breeder and non-breeder). Our results imply that populations of Manx shearwaters are comprised of in iduals with different demographic profiles, whereby more successful reproduction is associated with higher rates of survival and breeding propensity. However, we found that all birds experienced the same negative relationship between rates of survival and wind force during the breeding season, indicating a cost of reproduction (or central place constraint for non-breeders) during years with severe weather conditions. We also found that environmental effects differentially influence the breeding propensity of in iduals in different breeding states. This suggests in idual spatio-temporal variation in habitat use during the annual cycle, such that climate change could alter the frequency that in iduals with different demographic profiles breed thereby driving a complex and less predictable population response. More broadly, our study highlights the importance of considering in idual-level factors when examining population demography and predicting how species may respond to climate change.