PIBO MIGRATION SUMMARY
August 21st – August 31st, 2012
Black-throated Blue Warbler
The weather remained warm and humid during the first part of the summary period and not much migration activity was recorded from August 21st – 27th, but things picked up considerably on the 28th and it remained busy right through to the 31st. In all, 78 species were documented at Fish Point in the final eleven days of August and 250 birds of twenty-eight species were banded in 470 net-hours, for an average catch-rate of 0.53 birds/net-hour. Twenty-one fall ‘firsts’ were tallied including Black-crowned Night-Heron, Lesser Yellowlegs, Northern Parula, and Scarlet Tanager, among others.
Much of the lull from the 21st – 27th was likely due to seven straight days of southerly winds, which saw the daily species total (DT) at the station drop from a high of 49 on August 22nd to a season low of 18 on the 27th. But despite the less than ideal conditions, migrants continued to appear in moderate numbers even on some of the quieter mornings, including nine warbler species on the 21st, a banded Golden-winged Warbler (22nd), the first autumn Traill’s Flycatcher (23rd), 8 Red-breasted Nuthatches (24th), 3700 cormorants and the first Wilson’s Warbler of the fall (25th), and ones-and-twos of six warbler species on the 26th and 27th.
Light steady rain and some northerly winds on the 27th finally turned things around and a nice variety of birds showed up the next morning, with 57 species recorded during the official count period and 49 birds banded of sixteen species. Seven fall ‘firsts’ were tallied including Solitary Sandpiper, Philadelphia Vireo, Nashville and ‘Western’ Palm Warbler. Fifteen warbler species were observed. Fifty-seven species were noted again on August 29th including ‘firsts’ for Gray-cheeked Thrush and Blackpoll Warbler, and 85 individuals of sixteen species were captured. Swainson’s Thrushes, Magnolia Warblers and American Redstarts were numerous, along with a nice variety of other species.
The final two days of the month saw a slight drop-off in abundance and diversity but there were still quite a few birds in the area. Fifty-two species were recorded on the 30th, including fall ‘firsts’ for Blue-headed Vireo and Northern Parula, and 55 birds of ten species were captured. A group of 30 Cliff Swallows were noted at the tip on census along with 5000 Double-crested Cormorants. Strong southwest winds on August 31st saw a further decline in numbers, with 43 species documented on the day, including ten warbler species, and 30 birds banded of nine species.
PIBO’s next summary will be posted on September 12th.
Photo: Sumiko Onishi