PIBO MIGRATION SUMMARY
SEPTEMBER 11th - 20th, 2010

Gray-cheeked Thrush

It was an active mid-month at Fish Point and lots of neotropical migrants passed through the area on the way south to their wintering grounds in Central and South America. At the same time, a nice variety of new arrivals - temperate migrants that winter north of the tropics - started to appear in good numbers towards the close of the summary period, so it was a good mix of birds at the halfway point in PIBO's monitoring season.

At least 2000 Ringed-billed and Herring Gulls were active all week at the tip along with up to 50 Great Black-backs. Double-crested Cormorants remained numerous, with an estimated 7400 birds recorded in one hour on September 16th. Shorebirds were hard to find on the census and only a few Black-bellied Plovers and Sanderlings were tallied, as well as a couple of lingering Spotted Sandpipers. Hawk migration was more in evidence after the 14th and small groups of Sharp-shins were noted each day on the census along with a station-high 10 Bald Eagles loafing at the tip on the 14th, 5 Merlins on the 19th, and up to 6 Northern Harriers recorded almost daily.

Catharus thrushes dominated on the passerine front and lots of birds were banded, with 368 individuals of four species (Veery, Swainson's, Gray-cheeked and Hermit) captured from the 11th - 20th, including 78 and 52 Swainson's and 20 and 25 Gray-cheeks banded on the 14th and 15th, respectively. This activity continued right through to the 20th when 48 thrush spp. were captured, including the first banded Hermit Thrush of the Fall. September 19th was a curious day - 62 thrushes were banded that morning along with only two other birds - a Blackpoll Warbler and Ovenbird.

It was also active for a variety of other songbirds and quite a few new arrivals were noted including Yellow-throated Vireo, Ruby-crowned Kinglet and Scarlet Tanager (14th), Hooded Warbler (15th), Brown Creeper and Purple Finch (18th), and the first American Pipits and Golden-crowned Kinglets on the 19th and 20th. A range of other birds appeared in the nets in good numbers, with thirty-six species captured including Magnolia Warbler (49 banded over ten days), American Redstart (35), Black-throated Blue Warbler (31), Ovenbird (22) and Red-eyed Vireo (16), among others.

In all, 133 species have been recorded at Fish Point this Fall during PIBO's official count period and 1583 birds have been banded in 2042 net-hours, for an average catch-rate of .78 birds/net-hour. In keeping with the rapid turnover of migrants at the Point, only eighteen individuals have been recaptured again this autumn at least one day from the time of their initial banding, including a mere one percent of the thrushes (four recaptures of 368 birds).

PIBO just started up on Twitter a few weeks ago, so be sure to check us out for daily updates throughout the rest of the migration season at:

http://twitter.com/PeleeIslandBird

PIBO's next summary will be posted on October 2nd.

Photo: Sumiko Onishi