Extreme weather effects on marine predator breeding outcomes in a global climate change hotspot.

Abstract

Extreme weather events (EWEs) are increasing in both intensity and frequency globally. For long-lived, slow-reproducing marine predators, repeated or sequential EWE-driven breeding failures can have population-level consequences. We quantified effects of EWEs on reproductive output and identified temporal windows of vulnerability during breeding in three sentinel species across 14 colonies with varying population trajectories in Tasmania, Australia. Using long-term breeding datasets and daily weather records, we found that Australian fur seals (<i>Arctocephalus pusillus doriferus</i>), short-tailed shearwaters (<i>Ardenna tenuirostris</i>), and shy albatross (<i>Thalassarche cauta</i>) exhibited species- and colony-specific vulnerabilities. Storm surges reduced pup production in a low-lying fur seal colony, extreme rainfall lowered shearwater breeding success, and albatross productivity declined with exposure to extreme heat, rainfall, and wave events. These results highlight the importance of identifying critical extreme weather thresholds and periods of vulnerability to inform ecological forecasting. Proactive, climate-informed management strategies tailored to specific colonies are needed to enhance the resilience of vulnerable populations under accelerating climate change.