Hummingbird molt: preliminary observations.
ALLEN T. CHARTIER, Inkster, MI.
A comparison will be made between published sources for molt schedules in Ruby- throated and Rufous hummingbirds, based on preliminary data gathered in the western Great Lakes region from 2001 to 2005. Data from 2500+ Ruby-throated Hummingbirds banded suggests that published sources are probably accurate for HY birds, suggesting a complete molt from November to March, when the species is absent from the region. But AHY birds have been observed consistently undertaking a partial molt, involving all body feathers, from late July through mid-September. This partial molt is currently undocumented in the literature. While published sources for Rufous Hummingbird suggest that a complete molt occurs from August to March, observations from 26 Rufous Hummingbirds handled (21 banded) suggest that the strategy is more complex. Both HY and AHY birds may continue flight feather molt during early fall migration (July - September), and frequently suspend molt of the primaries, most often with p1 - p6 replaced. Rufous Hummingbirds also have been observed in light to heavy body feather molt from August through November.