Anthropogenic and Environmental Factors Influence Adult Survival in a Conservation Reliant Coastal Wader Population

Bird survival is influenced by both natural and anthropogenic factors, including weather conditions and oil spills. In this study, we examined the impact of a major oil spill (Prestige oil tanker) and climatic conditions (precipitation and wind) on survival and recapture probability in the Kentish plover (Anarhynchus alexandrinus) population in Galicia (NW Spain). To this end, we applied the Cormack-Jolly-Seber (CJS) live recapture model to a sample of 372 adult birds captured between 1994 and 2023. The best-fit model indicated that survival was best explained by the interaction between precipitation and the Prestige oil spill, indicating a decrease in survival post-spill, especially in the periods Post1 (years 2003–2007) (βP1 = -0.70 ± 0.26) and Post2 (2008–2015) (βP2 = -0.56 ± 0.27). Precipitation showed a negative influence on adult survival (βₚₚ = -0.71 ± 0.20), but wind had no significant influence. Recapture probability was influenced by the interaction between time, sex and Prestige, with males showing higher values (βsexMale = 3.67 ± 1.47), probably due to behavioural and detectability differences. Environmental monitoring and preparedness for pollution events are therefore essential to improve the long-term viability of the species.