Sunday, August 28, 2011

Metro Beach banding report - August 21 & 26, 2011

As expected, songbird migration began in earnest this week, though there were fewer birds on the 21st than on the 26th. The 21st had some rain mid-morning, requiring the nets to be closed for an hour with thunderstorms moving in while we took the nets down. Weather on the 26th was ideal.

Highlights of birds banded on Sunday, August 21 included four Ruby-throated Hummingbirds plus one recaptured that was originally banded on August 10.

Hatch-year male Ruby-throated Hummingbird

Some flycatchers were present and captured, including two Willow Flycatchers that appeared to have recently fledged. But the surprise was the Least Flycatcher which was an adult female with the remnants of a brood patch, suggesting that the species nested in the park though none were detected over the summer except in early June one was found along the nature trail.

After hatch-year female Least Flycatcher

Two Willow Flycatchers that appeared to be recently fledged, with short tails and giving raspy begging calls in the hand, were banded today.

Hatch-year Willow Flycatcher

An unusually early migrant, as they do not nest in the park, was a Rose-breasted Grosbeak caught out in the Field Nets (a second grosbeak right next to this one escaped before it could be extracted from the nets). This species is not captured often at this station, so they're always a treat to see up close.

Second-year male Rose-breasted Grosbeak

As can be seen in the photo above, this bird was still heavily molting. Male Rose-breasted Grosbeaks molt into a duller, female-like winter plumage, which is why its head and back looks like a female. But it was clearly a male because it had a fair amount of red on its breast (and pink on the under-wing coverts).

Second-year male Rose-breasted Grosbeak

Determining this bird's age required a closer look at the flight feathers to assess its molt. The presence of a very worn, dull brown inner secondary that was a remaining juvenile feather was a good indication he was in his second-year.

Second-year male Rose-breasted Grosbeak

Interesting birds observed but not banded included a flyover Cooper's Hawk, a Great Crested Flycatcher out near the field nets (seen when we were closing them to wait out the rain), and a couple Tennessee Warblers.

Highlights of birds banded on Friday, August 26 included 14 Ruby-throated Hummingbirds, the best day so far this fall. As is typical, most were hatch-year birds. Metro Beach probably hosts a couple breeding female hummingbirds, but in spring less than 10 are typically banded and they are not often seen during summer. In fall, between 50-90 have been banded in previous years, with the unusual age composition of approximately 90% hatch-years. As can be seen in the inset in the photo below, hatch-year birds show "corrugations" on the bill which look like small grooves; the bill smooths out by winter and no corrugations (or very few) are present on adults.

Hatch-year male Ruby-throated Hummingbird showing corrugations on bill (inset)

It was a great day for banding flycatchers. A nice surprise out in the Field Nets was only the second Olive-sided Flycatcher to be banded since 2004, and only the 4th ever, since 1989.

After hatch-year Olive-sided Flycatcher

That this is a long-distance Neotropical migrant, wintering in southern portions of the Amazon basin, can be seen by its long, pointed wings which are somewhat different from most of our flycatchers.

After hatch-year Olive-sided Flycatcher

It was also a good day for Empidonax flycatchers, among my favorite birds to band. Among the 7 individuals captured today was one Least, 3 Willows (including 2 recaptures of recently fledged young banded recently), and 3 Alders. Often, even after taking extensive measurements, some of these Willow/Alder Flycatchers ("Traill's"), they cannot be keyed out to species. Today, all of them keyed out, and the one in the photo below is an Alder Flycatcher based on those measurements. On-site, I had guessed that it was an Alder based on its brighter coloration and more complete, though narrow, eye ring among other characters. This probably only proves that I'm a good guesser, not that I can tell them apart without measuring them! Alders probably did not nest in the park this year, so this one was almost certainly a migrant.

Hatch-year Alder Flycatcher

Another large flycatcher, banded only occasionally here, dropped into the nets; a Great Crested Flycatcher.

After hatch-year Great Crested Flycatcher

Over the past two years, removal of invasive Autumn Olive from the banding area has been one habitat maintenance priority. In 2009, these trees provided berries for many Cedar Waxwings caught that year out in the Field Nets. This year, the dogwoods have regrown and are loaded with berries. Some waxwings have been caught this month, but I really believe that the record number of Warbling Vireos, and today's three Red-eyed Vireos, is because they may prefer dogwood to Autumn Olive. Time will tell, as the number of Red-eyed Vireos has been low for many years.

After hatch-year Red-eyed Vireo

The first migrant thrushes of the fall season were banded today, a little later than normal. Veery nests west and even south of Metro Beach, but there isn't enough appropriate habitat here, so today's bird was clearly a migrant.

Hatch-year Veery

This was followed by the season's first Swainson's Thrush. Adults have been banded here as early as the first week in August.

After hatch-year Swainson's Thrush

Eight species of warbler dropped into the nets today, plus one species recaptured from last week. These included the first Magnolia Warblers. There should be many more of these as their migration typically extends into the first week of October.

Hatch-year Magnolia Warbler

Cape May Warbler is one of the less frequent warbler species banded at Metro Beach, and in fact since 2004 only two have been banded here although it was nearly annual in small numbers from 1989-1999. Both were in the Field Nets (eating dogwood berries?) on the same net run, one a rather dull hatch-year female and the other a much brighter hatch-year male. This is one of the easier warblers to sex in the fall.

Hatch-year female Cape May Warbler

Hatch-year male Cape May Warbler

The first American Redstarts were banded today; like Magnolia Warblers, the migration of redstarts can extend into early October. Many birders would pass this individual off as a "female", but the orange on the flank patches indicates it is a hatch-year male.

Hatch-year male American Redstart

Mourning Warbler tends to be an early migrant, so capturing one today was expected. This individual is showing fairly prominent "eye arcs" that might lead some to think it is a rare vagrant, MacGillivray's Warbler, but the arcs are narrow and this bird is typical of many hatch-year Mourning Warblers. Not visible in this photo is the partly hidden blackish spots on the breast, indicating it is a male.

Hatch-year male Mourning Warbler

Another early migrant is the Canada Warbler, represented today by this adult female.

After hatch-year female Canada Warbler

And the first Wilson's Warblers are expected to arrive by late August.

Hatch-year male Wilson's Warbler

Following on a very good spring for Baltimore Orioles, it has been very good this fall as well with three banded today bringing the season's total to a record of 10.

After hatch-year male Baltimore Oriole

After hatch-year female Baltimore Oriole

Interesting birds observed but not banded included a Virginia Rail that almost got caught in the Field Nets, two Great Horned Owls calling to each other before sunrise, and a Blackburnian Warbler near the road.

Banding could not have been done on these two days without some very helpful, and cheerful (in the face of hordes of mosquitos) volunteer banding assistants, including Stevie Kurda, Dave Lancaster, Tom Schlack, and Bruce Watson. Also thanks to Jeff Silence for stopping by for an hour at a very helpful time in the morning on the 26th.

Banding Data
SUNDAY, August 21, 2011
Sunrise (E.S.T.): 5:45
Time Open (E.S.T.): 6:00
Time Closed (E.S.T.): 14:00
Hours Open: 7.00 (closed due to rain from 8:30-9:30)
No. of Nets: 2.50-13.50
Net Hours: 82.00
Temperature (F): 66-75
Cloud Cover: 40-100-50%
Wind: SW-W @ 1-3-7 mph
Barometer: 29.95-29.92
Precipitation: Brief light rain in a.m., showers after close
No. Banded: 21 (plus 11 recaptured and 2 released unbanded)
No. of Species: 14
Capture Rate: 41.5 birds per 100 net hours
Volunteers (worked 10.0 hours, 6:00-16:00): Stevie Kuroda, Bruce Watson.

Ruby-throated Hummingbird - 4 (plus 1 recaptured)
Willow Flycatcher - 2
Least Flycatcher - 1
American Robin - 2
Gray Catbird - 1
Yellow Warbler - 1 (plus 1 recaptured)
Northern Waterthrush - 1
Common Yellowthroat - 2 (plus 1 recaptured)
Song Sparrow - 3 (plus 5 recaptured and 1 released unbanded)
Swamp Sparrow - 1
Rose-breasted Grosbeak - 1 (plus 1 released unbanded)
[Red-winged Blackbird - 1 recaptured]
House Finch - 1
American Goldfinch - 1 (plus 2 recaptured)

FRIDAY, August 26, 2011
Sunrise (E.S.T.): 5:50
Time Open (E.S.T.): 5:45
Time Closed (E.S.T.): 13:15
Hours Open: 7.50
No. of Nets: 4.50-13.50
Net Hours: 91.75
Temperature (F): 61-77
Cloud Cover: 20-0%
Wind: NW-S @ 1-3-10 mph
Barometer: 30.09-30.10
Precipitation: None
No. Banded: 80 (plus 20 recaptures)
No. of Species: 29
Capture Rate: 109.0 birds per 100 net hours
Volunteers (worked 10.0 hours, 6:00-16:00): Dave Lancaster, Tom Schlack (plus Jeff Silence for 1 hour).

Ruby-throated Hummingbird - 14
Downy Woodpecker - 1
Eastern Wood-Pewee - 1
Alder Flycatcher - 3
Willow Flycatcher - 1 (plus 2 recaptured)
Least Flycatcher - 1
Great Crested Flycatcher - 1
Red-eyed Vireo - 3
Black-capped Chickadee - 1
House Wren - 1
Veery - 1
Swainson's Thrush - 1
American Robin - 1
Tennessee Warbler - 1
Magnolia Warbler - 4
Cape May Warbler - 2
American Redstart - 2
[Northern Waterthrush - 1 recaptured]
Mourning Warbler - 1
Common Yellowthroat - 4 (plus 1 recaptured)
Wilson's Warbler - 1
Canada Warbler - 1
[Song Sparrow - 5 recaptured]
Swamp Sparrow - 2
[Northern Cardinal - 1 recaptured]
Red-winged Blackbird - 4 (plus 2 recaptured)
Baltimore Oriole - 3
House Finch - 1
American Goldfinch - 23 (plus 8 recaptured)

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