Spring migration patterns of birds in montane habitats of the Southwestern United States

We characterized the distribution of migrating birds in high-elevation forested habitat in north-central New Mexico during spring migration. In contrast to many other stopover studies in the American southwest, we focused on a range of forested upland habitats rather than lowland riparian corridors. We censused birds in pinoñ-juniper woodland, ponderosa pine forest, and spruce-fir forest to ascertain the effects of mountain range and habitat on abundance and richness of Nearctic-Neotropical migrants. We detected 28 migratory species and found that migrants were associated with the two southern ranges (Manzano and Sandia mountains) significantly more than with the northernmost Sangre de Cristo Mountains, and Nearctic-Neotropical migrants were more abundant and species-rich in pinoñ-juniper and ponderosa pine habitats. The nonrandom distribution of migrating birds in this study, and the potential for climate-driven habitat change and anthropogenic use of forested habitat to affect migrating birds, indicates that upland forest in the southwestern United States deserves more research during the migratory period.