{"paper_id":"3a0fb33f-9c7a-404c-9182-5251e526f296","body_text":"This is a Preprint and has not been peer reviewed. This is version 1 of this Preprint.\nYou must log in to post a comment.\nThere are no comments or no comments have been made public for this article.\nThis is a Preprint and has not been peer reviewed. This is version 1 of this Preprint.\nAdd a Comment\nYou must log in to post a comment.\nComments\nThere are no comments or no comments have been made public for this article.\nClimate 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\nhttps://doi.org/10.32942/X2W37C\nLife Sciences\nclimate change, phenology, environmental predictability, variation\nPublished: 2026-03-27 00:24\nLast Updated: 2026-03-27 00:24\nCC BY Attribution 4.0 International\nConflict of interest statement:\nNone\nData and Code Availability Statement:\nAll 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/.\nLanguage:\nEnglish","source_license":"CC-BY-4.0","license_restricted":false}