Migration this week was cut short by the arrival of Hurricane Dorian. On the nights not affected by the hurricane, passage rates were down about 10 percent from the last week of August.
The most common species was again American Redstart with an estimated 362 birds, followed by Common Yellowthroat (284), and Bay-breasted Warbler (202). The high numbers of Bay-breasted Warblers, normally a much less abundant species, is an indication of the positive impact of spruce budworm infestations on its breeding population in the boreal forest. Other budworm-dependent species present were Cape May Warbler (134) and Tennessee Warbler (35). Canada Warblers were down to 40 estimated birds for the week after their spectacular showing in August.
Thrushes significantly increased from their late August levels with an estimated 190 Swainson’s Thrush and 38 Veery. Sparrows were still relatively scarce but an estimated 71 Savannah Sparrows were recorded.
Unusual birds for the week included 4 Prairie Warblers, 1 Sora, 1 Eastern Bluebird, and 1 Indigo Bunting.