Stopover habitat relationships of landbirds are not well known and this constitutes a shortcoming in conservation plans for migratory birds. We compared migrant use of mature upland and riparian forests during spring in an urbanizing landscape within central Ohio. We surveyed stopover migrants along 250-m transects, and quantified both local- and landscape-level habitat characteristics (percent urban and forest land). During spring stopover, migrant abundance was 86% and 118% higher in upland forests for Nearctic-Neotropical transient (long-distance migrants) and temperate transients (short-distance migrants), respectively. Of 27 transient species, 22 species differed in their use of riparian and upland forests, and 20 of those were most abundant in upland forest (e.g., Blue-headed Vireo [Vireo solitarius], Least Flycatcher [Empidonax minimus], Swainson's Thrush [Catharus ustulatus], Nashville Warbler [Vermivora ruficapilla], Magnolia Warbler [Dendroica magnolia], Bay-breasted Warbler [D. castanea], and Ovenbird [Seiurus aurocapillus]). Species richness was 58% and 75% higher in upland forests relative to riparian forests for Neotropical transient and temperate transient groups, respectively. Percent urbanization within 1 km was unrelated to abundance of Neotropical transients and temperate transients. Abundance of Neotropical transients and temperate transients was unrelated to percent forest cover within 1 km. Mature upland and riparian forests differed in that riparian sites had lower percentage of shrub cover, higher percentage of canopy cover, and different species composition of trees. Abundance of Neotropical transients was positively associated with mean canopy height; temperate transients were positively associated with mean number of trees >38 cm DBH and mean percentage of shrub cover. Our data indicate that mature upland forests were more heavily used by migrating landbirds than riparian forests within an urbanizing Midwestern landscape and may represent valuable habitats for the conservation of migratory landbirds within highly fragmented landscapes.

Uso de Bosques Riparios y de Llanuras por Aves Terrestres como Hábitats de Paradas Migratorias en un Paisaje Urbano

Resumen. Las relaciones de los hábitats que sirven como paradas migratorias para las aves terrestres no están bien conocidas, y esto constituye una deficiencia en los planes de conservación de las aves migratorias. Comparamos el uso de bosques maduros de llanuras y de bosques riparios por parte de aves migratorias durante la primavera en un paisaje que está siendo urbanizado en Ohio central. Registramos aves migratorias en las paradas de migración a lo largo de transectos de 250 m y cuantificamos las características del hábitat tanto a nivel local como a nivel del paisaje (porcentaje de cobertura urbana y de bosque). Durante la parada migratoria de primavera, la abundancia de las aves migratorias en bosques de llanura fue un 86% mayor para las aves transitorias del Neártico-Neotrópico (aves migratorias de larga distancia) y un 118% mayor para las aves transitorias templadas (aves migratorias de corta distancia). De 27 especies transitorias, 22 especies se diferenciaron en su uso de bosque ripario y de llanura, y 20 de éstas fueron más abundantes en bosques de llanura (e.g., Vireo solitarius, Empidonax minimus, Catharus ustulatus, Vermivora ruficapilla, Dendroica magnolia, D. castanea, Seiurus aurocapillus