PIBO Migration Summary

September 1st – 10th, 2012


Yellow-billed Cuckoo


It was a productive and enjoyable start to the month and the PIBO team was kept busy apart from one or two mornings towards the end of the summary period. In all, 92 species were recorded in the official count area from September 1st – 10th, including eight fall ‘firsts’, and 461 birds of thirty-one species were banded, including 236 Swainson’s Thrushes. A total of 463 net-hours over ten days made for an average catch-rate of 1.0 birds/net-hour.


September began on a busy note and a nice variety and number of birds were recorded on the 1st. All told, 68 species were noted during the official count period and 86 individuals of seventeen species were captured in sixty net-hours (1.4 birds/net-hour). Highlights included 77 Bobolinks observed heading south off the tip on the census, 62 Swainson’s Thrushes (including 43 banded), 45 Palm Warblers, 25 Magnolia Warblers, and 21 Red-eyed Vireos. Twenty warblers species were tallied on the day. Although nuthatches don’t seem very fond of crossing the lake, a noticeable increase has been observed at Fish Point this year – in keeping with other reports throughout the province – including 12 Red-breasted Nuthatches on the 1st,  


The pace continued on the 2nd when 58 species were counted and 85 birds of thirteen species were banded in forty-five net-hours (1.9 birds/net-hour). Purple Martins and Barn Swallows were numerous, with 64 and 90 individuals counted, respectively, along with more Swainson’s Thrushes (49), Red-eyed Vireos (27), American Redstarts (20) and Black-throated Blue Warblers (17, including 11 banded). Another busy morning on September 3rd saw 55 species recorded and 92 birds banded. Six thrush species were noted, including a somewhat early banded Hermit Thrush. An American Kestrel on the census was new for the fall.


Rain set in on the 4th and field coverage was limited to just three hours, but there were still quite a few birds in the area despite the less than ideal conditions i.e. southwest winds and a dawn temperature of 25° C. Similar conditions prevailed on September 5th, with 37 species tallied, including the first Merlin of the fall, and 18 birds were captured of six species. More southwest winds on the 6th and 7th saw a gradual decrease in activity, with 58 birds banded over the two day period, including two Connecticut Warblers. Six Blue-winged Teals and an American Pipit on the census were both ‘firsts’ for the season.


The wind shifted to the north on the evening of the 6th and staff were greeted with gale conditions and heavy rain on the morning of September 7th. No banding was carried out and just twenty-one species were recorded on the census. The north winds continued over the final two days of the summary period and bird numbers rebounded nicely, with 49 species documented on the 9th, including the first Green Heron of the fall, and 44 birds banded of ten species. Thirteen warbler species were noted on the day along with a nice variety of other birds in moderate numbers. Four young Bald Eagles were observed in a tree on the east beach during the census. Forty-eight species were tallied on September 10th and 57 birds were captured, including increased numbers of Gray-cheeked Thrush (10 banded) and the first Winter Wren of the season.


PIBO’s next migration summary will be posted on September 22nd.


Photo: Sumiko Onishi