Monday, September 3, 2012

Metro Beach banding station report - August 28 & September 1, 2012

Warblers increased slightly in number on August 28, and came in good numbers on September 1. But thrushes are still low in number, along with vireos and flycatchers. Good weather on both days allowed the station to be operated for the standard number of hours (6 hours after the last net is open). On Saturday, September 1, the remnants of Hurricane Isaac reached southern Michigan, giving us mostly just some cloudiness and high haze. The sky reminded me of the movie was an Isaac Haze :-). Younger readers may have to Google this to get the bad pun. Sorry.

Many thanks to the following volunteers who made banding on these two days possible: Terri Chapdelaine, Jacob Charlebois, Marie McGee, Joe Midgett, Tom Schlack, and Blanche Wicke.

Highlights of the 49 birds banded on Tuesday, August 28 included two Ruby-throated Hummingbirds, and a surprise Red-breasted Nuthatch.

Hatch-year female Red-breasted Nuthatch

Most years we see a post-breeding dispersal of Red-breasted Nuthatches that does not often indicate whether there will be a good or poor winter for this species in southern Michigan. And any time I've banded one of these August birds, it has been a hatch-year.

The first Swainson's Thrushes of the fall were captured today, about two weeks later than the typical first stragglers arrive.

Hatch-year Swainson's Thrush

A good number of Tennessee Warblers was banded today, putting us ahead of the typical pace for this species by late August. The first Nashville Warblers of the season were also banded today.

Hatch-year male Nashville Warbler

And the first Black-throated Blue Warbler of the season was this hatch-year female, with a very small wing spot (some lack it entirely).

Hatch-year female Black-throated Blue Warbler

The two classic "confusing fall warblers" are Bay-breasted and Blackpoll, and we had one of each today. Many hatch-year Blackpolls show yellow only on the soles of the feet, making that often-cited field mark difficult to use. A fairly consistent different between the two species, seen in the photos below, is that Blackpoll tends to be yellower on the throat and breast, and bright white on the undertail coverts, while Bay-breasted tends to be more olive on the breast and buffy on the undertail coverts. Banders have another character to check, the sixth primary which is emarginated (sometimes only slightly) in Bay-breasted and not emarginated in Blackpoll.

Hatch-year Blackpoll Warbler

Hatch-year Bay-breasted Warbler

Rose-breasted Grosbeaks are typically captured in September, if we catch any at all, but last fall we had two in August and today one was in the same unusual habitat, in the Field Nets. It was a hatch-year female based on the molt condition to determine the age, and the yellow wing linings to determine the sex.

Hatch-year female Rose-breasted Grosbeak

Interesting birds observed but not banded today included a juvenile Broad-winged Hawk chasing the resident Red-tail around for a while, and a Sora calling from the marsh. In the trees next to the banding station, a number of interesting songbirds were seen including a Philadelphia Vireo, and Blue-winged, Chestnut-sided, and Magnolia warblers. A few Bobolinks were heard flying overhead in the morning.

We often take some time to look at other things in the banding area when things slow down enough, and today there were several distractions including a chrysalis of a Monarch butterfly hanging from a grapevine right along the banding road.

Monarch butterfly chrysalis

Some years there are good numbers of orb-weaving spiders in the open fields, and this year appears to be one of those with several of these beautiful Banded Argiopes building webs among the vegetation.

Banded Argiope (Argiope trifasciata)

And on our last net run, I looked down into the grass along the roadside and saw a baby Northern Water Snake. So, of course, I picked it up

hatchling Northern Water Snake

He was quite feisty, and struck at the camera lens several times! So, I put him down in the road where he stood his ground for another last photo before hastily retreating into the swamp.

hatchling Northern Water Snake

Highlights of the 88 birds banded on Saturday, September 1 included the first Yellow-bellied Flycatcher of the fall. In recent years they've been scarce, but have sometimes been fairly common in the 1990s. The mainly green and yellow tones, including yellow on the throat, big-headed look, and bold yellowish eye ring are good marks to look for on this species in the field.

Hatch-year Yellow-bellied Flycatcher

An adult Red-eyed Vireo, aged by its red eye (hatch-years have brown eyes), was the first for the season and may have been a locally summering individual. Note that it is molting its body feathers so is probably not a migrant based on that.

After hatch-year Red-eyed Vireo

The first Veeries of the fall migration were banded today, but were a couple weeks later than expected.

Hatch-year Veery

The first Magnolia Warblers banded this fall included an impressive total of 7. The photo below is similar to many that get rejected for this blog as the bird is not holding still. But in this case, the raised wings allow the yellow rump to be seen, which can throw birders off who think the only warbler with a yellow rump is the Yellow-rumped Warbler!

Hatch-year Magnolia Warbler

There is no confirmed method for telling hatch-year males from females in the hand, despite some field guide illustrations suggesting that they can be told in the field. I have been working on this for many years, trying to sort through the variable plumages of Magnolia Warblers in fall, and I THINK that the ones with mostly black upper tail coverts, bold flank and back streaking, large white tail spots, and longer wings, are males, while females are smaller and much duller. Unfortunately, 80% of the hatch-years I see are in between these two extremes!

Another Black-throated Blue Warbler today was a male, aged as hatch-year mainly by skull ossification as plumage is not a reliable way to age this species.

Hatch-year male Black-throated Blue Warbler

More Bay-breasted and Blackpoll Warblers added to the interest, as well as a good number of Ovenbirds and the third Mourning Warbler of the season. The first Wilson's Warblers were represented by two hatch-years, a male and a female.

Hatch-year male Wilson's Warbler

Hatch-year female Wilson's Warbler

Interesting birds observed but not banded included a briefly seen Osprey, a calling Red-breasted Nuthatch, and Black-throated Green and Chestnut-sided warblers and a Northern Waterthrush. Several Bobolinks flew overhead in the morning, and a couple of Baltimore Orioles were calling most of the day next to the banding station. Very few Ruby-throated Hummingbirds were in the banding area today, when normally there should be quite a few, and none were banded.

Banding Data
TUESDAY, August 28, 2012
Sunrise (E.S.T.): 5:52
Time Open (E.S.T.): 6:00
Time Closed (E.S.T.): 13:00
Hours Open: 7.00
No. of Nets: 4.5-13.5
Net Hours: 87.50
Temperature (F): 64-77
Cloud Cover: 10-30%
Wind: NW @ 3-5-10 mph
Barometer: 30.08-30.10
Precipitation: None
No. Banded: 49 (plus 2 recaptured)
No. of Species: 14
Capture Rate: 58.3 birds per 100 net hours
Volunteers (worked 9.50 hours, 5:00-14:30): Jacob Charlebois, Marie McGee, Tom Schlack, Blanche Wicke.

Ruby-throated Hummingbird - 2
"Traill's" Flycatcher - 1
Red-breasted Nuthatch - 1
Swainson's Thrush - 2
Tennessee Warbler - 6
Nashville Warbler - 2
Black-throated Blue Warbler - 1
Bay-breasted Warbler - 1
Blackpoll Warbler - 1
American Redstart - 2
Song Sparrow - 6 (plus 1 recaptured)
Swamp Sparrow - 1
Rose-breasted Grosbeak - 1
American Goldfinch - 22 (plus 1 recaptured)

SATURDAY, September 1, 2012
Sunrise (E.S.T.): 5:56
Time Open (E.S.T.): 5:45
Time Closed (E.S.T.): 12:45
Hours Open: 7.00
No. of Nets: 4.5-13.5
Net Hours: 87.50
Temperature (F): 64-81
Cloud Cover: 50-80-50%
Wind: NW-Calm @ 5-7-0 mph
Barometer: 30.15-30.15
Precipitation: None
No. Banded: 88 (plus 6 recaptured and 1 released unbanded)
No. of Species: 20
Capture Rate: 108.4 birds per 100 net hours
Volunteers (worked 9.0 hours, 5:00-14:00): Terri Chapdelaine, Joe Midgett, Blanche Wicke.

[Ruby-throated Hummingbird - 1 released unbanded]
Yellow-bellied Flycatcher - 1
Least Flycatcher - 1
Red-eyed Vireo - 1
Black-capped Chickadee - 2
Veery - 2
Swainson's Thrush - 3
Tennessee Warbler - 8
Nashville Warbler - 6
Magnolia Warbler - 7
Black-throated Blue Warbler - 1
Bay-breasted Warbler - 2
Blackpoll Warbler - 7
American Redstart - 1
Ovenbird - 5
Mourning Warbler - 1
Common Yellowthroat - 11 (plus 2 recaptured)
Wilson's Warbler - 2
Song Sparrow - 15 (plus 1 recaptured)
Northern Cardinal - 2
American Goldfinch - 10 (plus 3 recaptured)

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