Work

Early post-release survival and predation in headstarted Eurasian Curlews Numenius arquata

Year: 2025

Type: article

Abstract: Grassland-breeding waders are highly vulnerable to population declines, primarily due to the combination of agricultural intensification and predation. In Europe, agri-environment schemes (AESs) and site protection have been the main strategies implemented in order to improve breeding success. Additional various actions have also been taken in an effort to improve breeding success. However, despite these efforts, many wader populations continue to decline. Recently, headstarting, which includes the collect eggs from the wild, the raising of chicks in captivity, and releasing them, has been employed to help restore endangered species. This study examined the early post-release survival of GPS-tracked headstarted Eurasian Curlews Numenius arquata (n=63) at several sites in Poland. We identified the period when the birds were most vulnerable to predators, the types of predators involved, and the timing of predation. Habitat factors affecting the probability and timing of predation were also analysed. Overall survival from release to migration was 0.42, with the highest mortality occurring within the first seven days after release. Year, release site, cohort size, and release day (Julian date) had no effect on survival. All mortalities occurred as a result of predation. Most predation occurred during the day, with mammalian predators recorded more frequently than avian predators. The probability of predation was higher in areas with greater total lengths of roads and ditches, as well as a higher number of habitat patches. Daytime predation was more likely in the vicinity of trees, while night-time predation was more common in close proximity to buildings. While headstarting shows promise as a conservation tool, the predation risk to released headstarted birds can impact on its effectiveness. The results of this study offer guidance for future improvement of headstarting projects and for supporting the recovery of declining grassland-breeding wader populations.

Source: Global Ecology and Conservation

DOI: 10.1016/j.gecco.2025.e03922

Authors: Przemysław Obłoza, Dominik Krupiński, Michał Korniluk, Joachim Siekiera, Frédéric Jiguet, Zbigniew Kasprzykowski

Institutions: University of Siedlce, Centre National de la Recherche Scientifique, Sorbonne Université, Centre d'Écologie et des Sciences de la Conservation

Language: English

Topic: Avian ecology and behavior

Subfield: Ecology

Field: Environmental Science

Domain: Physical Sciences

SDG: Life on land

Open Access status: gold

Estimated APC paid: $2,980