The collapse of environmental predictability erodes reproductive success in a Tropical seabird

This is a Preprint and has not been peer reviewed. This is version 1 of this Preprint. You must log in to post a comment. There are no comments or no comments have been made public for this article. This is a Preprint and has not been peer reviewed. This is version 1 of this Preprint. Add a Comment You must log in to post a comment. Comments There are no comments or no comments have been made public for this article. Climate change can alter not only when seasonal events occur on average, but also how predictable they are from year to year. Many long-lived seabirds show a paradox: breeding dates remain stable even as populations decline. Using two decades of data from Blue-footed Boobies (Sula nebouxii), we tested whether loss of environmental predictability could reduce reproductive success even when mean timing remained stable. Mean timing of the winter–spring phytoplankton bloom and mean breeding mismatch showed no clear trend, but year-to-year variability in bloom timing increased markedly. Mismatch relative to bloom onset became more variable, and both expected nest success and its consistency declined. These results show that predictability loss can erode synchrony and demography even when mean timing appears unchanged https://doi.org/10.32942/X2W37C Life Sciences climate change, phenology, environmental predictability, variation Published: 2026-03-27 00:24 Last Updated: 2026-03-27 00:24 CC BY Attribution 4.0 International Conflict of interest statement: None Data and Code Availability Statement: All data, code, and materials needed to evaluate the conclusions of this paper are publicly available. The project GitHub repository and companion website provide a fully documented, step-by-step workflow for reproducing all analyses and figures. The GitHub repository is available at https://github.com/Santiago-0rtega/Collapse_environmental_predictability_erodes_reproductive_success, and the companion site is available at https://santiago-0rtega.github.io/Collapse_environmental_predictability_erodes_reproductive_success/. Language: English