SPRING MIGRATIONS OF ALDER AND WILLOW FLYCATCHERS IN SOUTHERN ONTARIO

The spring migrations of Willow Flycatchers (Empidonax traillii) and Alder Flycatchers (E. alnorum) at Long Point, Ontario peaked in early June with median dates for both species on 2 June. Although timing of occurrence of the two species did not differ significantly, Willow Flycatchers tended to have a somewhat earlier, longer migration period, with the middle 90% of the records occurring 20 May-9 June, compared with 30 May-10 June for Alder Flycatchers. Wing lengths indicated that male Willow Flycatchers migrated earlier in spring than females, and the same was probably true of Alder Flycatchers. Molt was negligible. Willow Flycatchers, Alder Flycatchers and Yellow-bellied Flycatchers (E. flaviventris) migrated almost simultaneously, but Least Flycatchers (E. minimus) arrived an average of 15 d earlier than the other three species.