Snow buntings ( Plectrophenax nivalis, Salomonsen, 1931) are widespread Arctic passerines, yet population trends and demographic parameters are largely unknown across their range. Here, we present the first estimates of adult survival rates for snow buntings using long-term live capture–mark–recapture and dead recovery data from two wintering sites in northeast Iceland (Stórutjarnaskóli and Akureyri, 1982–2020) and a breeding site in west Iceland (Flatey, 1975–2023). Using Burnham models, we found that mean apparent adult annual survival was 0.64 ± 0.03 0.57, 0.70 (±SE and 95% confidence interval) at Stórutjarnaskóli and 0.54 ± 0.09 0.37, 0.70 at Akureyri, but was lower at the Flatey breeding site (0.43 ± 0.11 0.23, 0.65). Recapture rates declined markedly after 1990, especially at winter sites, consistent with increased trap wariness, reduced site fidelity, or declines in local abundance. Annual breeding pair counts on Flatey from 1975 to 2023 showed a significant decline over time, even after accounting for variation in search effort, further supporting concerns of long-term population decreases. These findings provide key baseline demographic information for Iceland’s snow bunting population and highlight the potential impacts of climate-driven changes on Arctic birds.
Thorstensen et al. (Thu,) studied this question.