2025/04/14 by Nuwanthika P. Nagode, John A. Muller, Daizaburo Shizuka +1 · 1 voice
Biochemistry, Genetics and Molecular Biology · Agricultural and Biological Sciences · Environmental Science · #Plant and Fungal Interactions Research #Plant and animal studies #Wildlife Ecology and Conservation
paper · pdf · doi:10.1080/15594491.2025.2472436
Birds often aggregate into more dense groupings during nonbreeding than breeding periods, and understanding what drives flocking behavior during the nonbreeding period is essential for guiding their management. These groupings include large flocks of wintering grassland birds, such as the migratory Chestnut-collared Longspur (Calcarius ornatus). Identifying the spatial scale at which flock membership remains consistent is important for informing the management of their winter habitats. We examined the social behaviors of wintering Chestnut-collared Longspurs in Oklahoma, USA. We captured and tracked individual Chestnut-collared Longspurs during two winters between 2018 and 2020 and analyzed their social network structure. We found that this population consistently clustered into social communities rather than being associated with resource clustering alone. In the winter seasons we studied, 66% (2018–2019) and 93% (2019–2020) of individuals had associations solely within their community, and an additional 33% (2018–2019) and 8% (2019–2020) of individuals had at least 60% of their associations within the community. The number of associations an individual experienced did not depend on sex or age. Since Chestnut-collared Longspurs occur in flocks in winter, managers should consider the spatial requirements of flocks, ranging from 38 ha to 2468 ha, rather than individual spatial requirements. Thresholds for flock cohesion appear to differ across years and are likely driven by the availability of resources, such as seeds and surface water, rather than individual spatial requirements.