Data from: Survival and recruitment dynamics of black-legged kittiwakes Rissa Tridactyla at an Alaskan colony
McKnight, Aly et al. (2020), Data from: Survival and recruitment dynamics of black-legged kittiwakes Rissa Tridactyla at an Alaskan colony, Dryad, Dataset, https://doi.org/10.5061/dryad.ch2740k
Most seabirds breed colonially and exhibit considerable site fidelity over the course of their long lifespans. Initial colony selection can therefore have substantial fitness consequences, but factors contributing to recruitment into colonies and subsequent fidelity remain unclear. We used multi-state capture-recapture models to test several hypotheses related to apparent fledgling survival, probability of recruitment to natal colonies, and apparent post-recruitment survival in Black-legged Kittiwakes Rissa tridactyla, using data from individuals banded as chicks and subsequently resighted at a colony in south-central Alaska over a 20-year period. Competitive models suggested that apparent fledgling survival declined throughout our study. This decline was likely driven by intrinsic, cohort-specific processes and was not explainable by post-fledging weather or climate conditions. Independent resightings at other colonies suggest the apparent decline may have been at least partially influenced by permanent emigration (natal dispersal), which occurred more frequently when the colony size was large. Recruitment was primarily age-dependent, with no detectable effects from early life experience or from annual changes in four factors: colony size, colony productivity, climate, or average weather conditions. We estimated an average recruitment age of seven years, which is older than typically reported for Atlantic kittiwake populations and which supports a more conservative life history strategy for kittiwakes in the Pacific. Variation in the apparent survival of recruits was cohort-specific and did not correlate with age or annual changes in the factors listed above. Instead, apparent survival of recruits was best explained by colony size during a cohort’s second year, suggesting a degree of negative density dependence in post-recruitment survival or fidelity. This information could prove useful to managers deciding how to allocate resources among small, growing colonies and large, well-established colonies.
Prince William Sound