Friday, August 7, 2009

Fall Banding. Yes, Fall Banding!

Believe it or not, its that time of year again. Some birders are aware that Arctic shorebirds begin migrating southward during July and head out to the nearest mudflats and beaches to see them. But the beginnings of songbird migration goes largely unnoticed. I have been opening the banding station at Metro Beach Metropark, Macomb County, Michigan the first week of August partly to sample the population of young birds produced during the summer on the edge of Point Rosa Marsh, but also to begin banding near the very start of songbird migration. And both days spent banding this week delivered both young birds hatched locally and migrants from northern Michigan and beyond.

On Sunday, August 2, an eager group of 7 volunteers, plus me, started out late in the morning (8 a.m.) clearing the net lanes and getting them ready for the banding season. Most of the net lanes were in good shape, so only needed a branch or two trimmed, but the trail out to the Field Nets, and the net lanes out there, had become quite overgrown as they always do. Thankfully, this year a new volunteer, Aaron Potts, brought two gas-powered weed-whackers and cut a couple hours off our labors. So, the nets were opened a little before lunchtime and kept open for about 4 hours. The banding highlights today included three Cedar Waxwings, which we don't catch every year.

After hatch-year female Cedar Waxwing

A single Eastern Wood-Pewee and two Warbling Vireos were other infrequently banded species, and which we usually only band in early August. The biggest surprise was the capture of not one, but two Swainson's Thrushes. This species nests more than 100 miles north of here, so were definitely early migrants. A single Ruby-throated Hummingbird banded was also a highlight, as any day banding a hummingbird is a good day!
On Tuesday, August 4, a good number of Yellow Warblers was captured, probably the last day where there will be a high count of these and several showed fat deposits indicating that they were migrants and not summer residents. Juvenile sparrows made a good showing, with lots of young Song Sparrows and a few Swamp Sparrows. Their plumages were confusing enough that I had to resort to assessing the wing formula given in the Pyle Guide we use for banding. A juvenile flycatcher was captured today too, out at the Field Nets where a pair of Willow Flycatchers has clearly nested. This youngster had a short tail, wings, and bill, which means that the measurements necessary to confirm it as a Willow Flycatcher could not be made.

Hatch-year Willow Flycatcher

Another highlight was the capture of two Marsh Wrens. They breed in the marsh and are present during May, but for some reason we never, never catch them in spring...only in fall.

Hatch-year Marsh Wren

Migrants were once again captured today, with a Swainson's Thrush originally banded on Sunday recaptured, and a surprisingly early Tennessee Warbler. This species apparently is one of few passerines known to undertake a "molt migration", departing the breeding grounds early for a staging area where they molt before continuing their migration. Today's bird was a second-year female, as indicated by very worn plumage and other characteristics. And she had apparently very recently departed the breeding grounds as her brood patch was still very well developed. Very few Tennessee Warblers nest in Michigan, and well to the north of Metro Beach. These early second-year female Tennessee Warblers have been turning up at the banding stations of the Kalamazoo Nature Center for years but this is the first time one has turned up here.

Second-year female Tennessee Warbler

Many thanks to the hard working volunteers who helped clear the net lanes on Sunday, and who helped set up and operate the station on Tuesday: Dave Furi, Andy Johnson, Thierry Lach, Aaron Potts, Renee Render, Amanda Sheehy, Jason St. Pierre, Cathy Thiesen, and joan Tisdale.

Banding Data
SUNDAY, August 2, 2009

Sunrise (E.S.T.): 5:25
Time Open (E.S.T.): 8:45
Time Closed (E.S.T.): 13:15
Hours Open: 4.50
No. of Nets: 3.75-13.75
Net Hours: 44.125
Temperature (F): 68-73
Cloud Cover: 20-40%
Wind: W @ 1-3-10 mph
Barometer: 29.93-29.95
Precipitation: None
No. Banded: 23 (plus 6 recaptured)
No. of Species: 14
Capture Rate: 65.7 birds per 100 net hours
Volunteers: Dave Furi, Thierry Lach, Aaron Potts, Renee Render, Amanda Sheehy, Jason St. Pierre, Joan Tisdale

Ruby-throated Hummingbird - 1
Downy Woodpecker - 1
Eastern Wood-Pewee - 1
"Traill's" Flycatcher - 1
Warbling Vireo - 2
Black-capped Chickadee - 1
House Wren - 3
Swainson's Thrush - 2
American Robin - 2
Gray Catbird - 1 (plus 1 recaptured)
Cedar Waxwing - 3
Yellow Warbler - 2 (plus 2 recaptured)
Common Yellowthroat - 1 (plus 1 recaptured)
Song Sparrow - 2 (plus 2 recaptured)

TUESDAY, August 4, 2009
Sunrise (E.S.T.): 5:27
Time Open (E.S.T.): 6:00
Time Closed (E.S.T.): 12:00
Hours Open: 6.0
No. of Nets: 5.50-13.75
Net Hours: 76.125
Temperature (F): 73-81
Cloud Cover: 60-80%
Wind: SW @ 5-10 mph
Barometer: 29.90-29.87
Precipitation: None
No. Banded: 46 (plus 10 recaptured)
No. of Species: 16
Capture Rate: 73.6 birds per 100 net hours
Volunteers: Andy Johnson, Cathy Thiesen

Downy Woodpecker - 2
Willow Flycatcher - 1
Warbling Vireo - 1
House Wren - 1
Marsh Wren - 2
[Swainson's Thrush - 1 recaptured]
American Robin - 1
Gray Catbird - 1 (plus 1 recaptured)
Cedar Waxwing - 2
Tennessee Warbler - 1
Yellow Warbler - 14 (plus 3 recaptured)
Common Yellowthroat - 1 (plus 1 recaptured)
Song Sparrow - 14 (plus 4 recaptured)
Swamp Sparrow - 3
Red-winged Blackbird - 1
Baltimore Oriole


Laurent said...

Allen, I always wanted to ask something about the word "recaptured". Does it mean it is a bird that has been already captured by the same bander during the same season? year? day?

Allen Chartier said...

Laurent, the term "recaptured" is a general term used to describe a previously banded bird being captured again. I use this term for simplicity to include any or all of the following:

1) A bird banded previously the same season

2) A bird banded previously in a prior season

3) A bird banded previously in a different year

Laurent said...

Thanks for the tip, Allen!