Stopover habitat quality may influence the abundance of migrant landbirds, yet little is known about how spatial and temporal changes in stopover habitat quality influence the use of habitats by migrant landbirds. From late April to late May, 1997–1999, we surveyed migrant landbirds within five habitats (early successional shrub-sapling-stage forest, midsuccessional pole-stage forest, mature forest interior, mature forest-agricultural edge, and mature suburban forest) in central Pennsylvania. To assess relative quality of stopover habitats, we measured species abundance, species richness, and foraging behavior of Yellow-rumped Warblers (Dendroica coronata). We measured vegetation structure and phenology to examine proximate cues of potential importance in habitat selection. Of nine transient (nonbreeding) species analyzed, seven-Least Flycatcher (Empidonax minimus), Nashville Warbler (Vermivora ruficapilla), Northern Parula (Parula americana), Magnolia Warbler (D. magnolia), Black-throated Blue Warbler (D. caerulescens), Yellow-rumped Warbler, and Blackpoll Warbler (D. striata)-were most abundant in mature forests, and especially edge-dominated mature forests (forest-agricultural edge and suburban forest). Habitats used by mature-forest-breeding transients changed between years, but edge-dominated forest types were used most frequently in all three years. Although canopy leaf development at mature forest sites showed little relationship to site use by mature-forest-breeding transients within weekly intervals, year-to-year differences in leaf phenology were consistent with year-to-year changes in habitat use by migrant landbirds. Foraging behavior of Yellow-rumped Warblers suggested higher food availability and quality in forest-agricultural edges, compared with suburban forest and forest interior. Mature-forest-breeding transients were positively associated with sites that had large trees (>38 cm diameter at breast height) and denser understory vegetation (stems 0–2.5 cm in diameter). Extensive use of mature edge-dominated forests by migrating forest birds during spring suggests that these habitats may be important for the conservation of migrant landbirds.

Uso de Hábitat durante las Escalas Migratorias por Aves Migratorias Terrestres: el Papel de la Estructura del Hábitat, el Desarrollo de las Hojas y la Disponibilidad de Alimento