FALL MIGRATION MONITORING PROGRAM

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Bander-in-charge: Simon Duval
Assistants: Jean Bacon, Nancy Boily, Jane Cormack, Jean Demers, Nicki Fleming, Marie-France Julien, Kristen Keyes, Barbara MacDuff, Betsy McFarlane, Chris Murphy, Catherine Russell, Charles Seguin, Clémence Soulard, Patricia Stotland, Rodger Titman

Notes:   For a second week in a row, the number of birds banded was a near match for our five-year average. Our fall 2010 total though remains over 100 birds ahead of any previous year at this point in the season, but the pace will have to pick up next week in order to keep ahead of the 2008 count, when a substantial influx of birds moved through in week 6.  As has been the case so far this fall, the number of species observed is below the long-term average; this week the number of species banded is also lower than ever before in week 5 (previous range 34 to 44).

Among the observation highlights this week were the first American Woodcock of the year, and 5 Bank Swallows flying right overhead during the outdoor tally of Tuesday's totals, a new species for this fall.  Others seen for the first time this season were Northern Harrier, Northern Parula, Orange-crowned Warbler, (Western) Palm Warbler, Blackpoll Warbler, and Brown-headed Cowbird.  Three of these (Northern Parula, Western Palm Warbler, and Blackpoll Warbler) were also banded for the first time this fall, as was Myrtle Warbler, a species which we expect to being plenty of later this month.

Again this week we recaptured a bird previously banded at MBO and not observed for a long period; this time it was a Gray Catbird banded on September 25, 2007, and recaptured this week on September 2.  That happened to also be the busiest day of the week in the nets, with 38 birds banded that day, and the 51 species observed is the highest daily count yet this season.  Contributing to that total were 7 raptor species; 7 were also counted on Tuesday and 6 on Wednesday, so it was quite a good few days for hawk migration.  Northern Harrier, Northern Goshawk, Red-tailed Hawk, and Merlin were seen on all three days, while the highest total count went to Cooper's Hawk, thanks to 7 passing over on Thursday alone.

After five years of migration monitoring at MBO, there is only one week in either spring or fall in which the same species was the most frequently banded every year - and by making it to number one again this week, Magnolia Warbler has managed to extend that streak to six years for week 5 of fall.  Overall it was another good week for warblers, with them occupying seven of the top ten spots.  The biggest surprise is the big count of Northern Waterthrush, which included 10 individuals on Friday alone.  Tennessee Warbler and Common Yellowthroat also jumped up this week to tie with the waterthrush for second place, while this is by far the earliest in any fall that we've banded this many Black-throated Blue Warblers in a single week.  The 8 Black-and-white Warblers this week pushed them to 31 for the season, a new record high.  There was a sharp drop in American Redstarts this week, but we still managed to band 8 of them as well, and that also resulted in a new season record, at 107 and counting.  Indigo Bunting is on the list for a fourth consecutive week; it has never previously appeared more than four times in an entire season, and the traditional peak period is yet to come.  The top three species for the season to date are Song Sparrow (136), Magnolia Warbler (110), and American Redstart (107), then there is a big gap to fourth place, currently held by Common Yellowthroat (58).

For the third week in a row, the same four species occupy the top of the list of species most frequently observed, but they shuffled position this week and Common Grackle shot out to a dramatic lead thanks to big flocks early in the week, including counts of 593 on Sunday and 385 on Monday.  Common Grackle numbers in week 5 were similar to this in 2005 and 2006, but in more recent years the flocks didn't peak until October, so it will be interesting to see how the numbers continue over the rest of this season.  Most of the other species in the top ten changed relatively little compared to last week, but Rock Pigeon and Common Yellowthroat eked into a tie for tenth place, while Gray Catbird, Magnolia Warbler, and American Redstart dropped off the list.  

A couple of weeks ago we reported on a hatch-year Swamp Sparrow that was replacing its primaries.  Here is another one, banded on August 8 in full juvenile plumage, and now just completing replacement of its primaries and alula. (Photo by Simon Duval) One of the pieces of data we record for each bird banded at MBO is fat level; this Baltimore Oriole was positively bursting with fat and is no doubt on the verge of taking off for its long-distance migration. (Photo by Simon Duval) Meanwhile, some other species have nested late and still have young to care for, as shown by this barely-out-of-the-nest Gray Catbird banded this week.   (Photo by Simon Duval)

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