Autumnal migration was studied with high-resolution radar, ceilometer, and
daily census in the area of Franconia Notch, a major pass in the northern A
ppalachian Mountains. Under synoptic conditions favorable for migration, br
oadfront movements of migrants toward the south passed over the mountains,
often above a temperature inversion. Birds at lower elevations appeared to
be influenced by local topography. Birds moving southwest were concentrated
along the face of the mountain range. Birds appeared to deviate their flig
hts to follow local topography through the pass. Specific migratory behavio
r was not associated with species or species groups. Under synoptic conditi
ons unfavorable for southward migration, multimodal movements probably asso
ciated with local flights were as dense as the southward migrations describ
ed above. Avian migrants reacting to local terrain may result in concentrat
ions of migrants over ridge summits or other topographic features.