Overwinter movement ecology of two Sparrow species in southeastern Ohio.

Anthropogenic development and land use changes, including habitat loss and fragmentation, have resulted in the decline of many North American birds. Overwintering birds need food resources to meet energetic demands, thermal refugia to reduce energetic costs, and cover to avoid predation. To address how overwintering birds navigate human-dominated landscapes, including the response to a prescribed burn, we used automated and manual radiotelemetry to quantify the overwinter habitat use by Slate-colored Juncos (Junco hyemalis) and American Tree Sparrows (Spizelloides arborea) in southeastern Ohio during the winters of 2023 and 2024. Slate-colored Junco mean home range size was 17.0 ha (95% CI: 15.1–18.9) while American Tree Sparrow mean home range size was 27.1 ha (95% CI: 24.3–30.1). Although habitat use and habitat breadth differed between the two species, both selected edges and used residential areas and roads. Juncos selected or used tall field and forests proportionally, depending on site and year. Slate-colored Juncos used shrublands proportionally but avoided short fields. In contrast, American Tree Sparrows used tall and short fields throughout the winter and we documented a shift in habitat use in response to prescribed fire. Before the prescribed fire, American Tree Sparrows selected shrublands and used forests proportionally, but after the burn, selected burnt fields, used shrublands, and avoided forests. Temporal variation in habitat use by Slate-colored Juncos and American Tree Sparrows highlights the importance in understanding how fluctuation in resource availability due to seasonal variation and management affect the use of habitat patches within the landscape. Public and private landowners can support overwintering granivorous birds by providing tall field, edge, and shrubland habitat while reducing lawn and other mowed fields.