Demographic changes in a shorebird population in concomitance with the COVID-19 anthropause

Animal response to different levels of human activity is relevant to applied ecology and to guide conservation actions. Evidence on animal responses to the COVID-19 lockdown spans a wide range of biological and ecological proofs, albeit an evaluation at the level to which vital rates drive population dynamics is still lacking. We examined changes in the demographic contribution of survival and recruitment processes to population growth before, during, and just after the COVID-19 lockdown, in a shorebird species that is subject to human perturbation on breeding habitats, mainly due to recreational activities. We applied a model-based approach, that allows inference on variation of population growth rate and associated vital rates (apparent survival probability and per-capita recruitment) over time, to capture-mark-reencounter data from the Italian kentish plover Charadrius alexandrinus breeding population. A temporary change in demography was recorded following the COVID-19 lockdown carried out during the 2020 breeding and pre-breeding season. Prior to COVID-19 lockdown, the study population was decreasing, with a higher contribution of survivors from the previous year to the breeding population of the following year than from recruitment. This pattern was temporarily reversed during and just after the lockdown, when per-capita recruitment and its contribution to population growth rate more than doubled, leading to an increase in the population. Our study provides insights into the response of demographic processes of a bird species to the halting of human perturbation, as happened during the COVID-19 lockdown.