Sunday, August 14, 2011

Metro Beach - Fall Banding Season Begins!

It has been a productive summer for banding hummingbirds, though with only one species there isn't much to blog about and photos would tend to get repetitive! Back in June, I promised that the spring banding report would be finished "soon". Well, that day has arrived, and the full report can be dowloaded as a PDF file at my Metro Beach Banding web page. Just scroll down to the Spring 2011 Banding Report link.

The Fall 2011 banding season began on Sunday, August 7, with three volunteers turning out to clear net lanes and see what we might band once everything was set up. This first day is always unpredictable, as there can be quite a lot of vegetion grown into the net lanes over the summer. As I'd been conducting surveys once a week all summer, I knew we were in for a lot of work. I really hate gas-powered garden implements...or gas-powered anything for that matter. But it was a real time saver that the park maintenance department loaned us a weed whacker. It saved time until it jammed before getting to the longest stretch out into the field, and although they were very helpful in getting it unjammed for me, and refilling the tank with gas, I hooked the gas cap on the inside of the back of my car and dumped all the gas out into the car. A week later it is still smelling like gas. So, we had to take turns using the manual weed whacker all the way out into the field. It was a long, hot morning, but we got the job done. Around noon we decided to put up six of the nets for a couple hours to see what we could catch. It was the heat of the day, so bird activity was low, and we only caught 3 birds. The first bird caught and banded for the Fall 2011 season was a species not banded in spring, in a family also not banded in spring, a Warbling Vireo.

Hatch-year Warbling Vireo

From the photo above, some might see a suggestion of dark lores, and some yellow on the underparts, and wonder if it might be an early migrant Philadelphia Vireo. Luckily, the diagnostic character of this bird was visible,and I've highlighted it in an inset (click on the photo to enlarge). In vireos, the 10th (outermost) primary is vestigial so is much shorter than the others. In Philadelphia Vireo, it does not extend past the primary coverts on the folded wing, while in Warbling Vireo it does extend past them. The other two birds banded today were a juvenile Common Yellowthroat and an adult female Swamp Sparrow with a fully developed brood patch.

One of the reasons for starting the fall banding season so early is to assess the nesting productivity in the banding area, so we look forward to catching lots of young birds of locally nesting species. Surveys through the summer saw parent birds with beaks crammed full of Mayflies (Ephemeroptera, often erroneously called "fish flies"), which this summer provided a better than average bounty for nesting birds.

Ephemeroptera (Mayflies) on Nature Center. 7 July 2011.

Elsewhere in the park, birds are also still attending young, but a large part of the park's area is taken up with a huge parking lot (see map here). In 30+ years of visiting this park, I have never seen so many beach-goers that this lot was close to even half full. For much of the year, this vast expanse of asphalt is as welcoming to life as the surface of the Moon. But from late summer into fall, gulls find portions attractive for loafing much of the day. And often there are interesting things mixed in, like a few Killdeer, and Caspian Terns with begging juveniles. The adult Caspian Terns try to ignore them at this age, mostly just running away from them as they squeal and beg.

The first full day of fall banding, Wednesday, August 10, was possibly the best opening day since I began here in 2004, with a total of 84 new birds banded and 10 recaptures. Last year's first full banding day netted only 21 birds, while other recent years have started with 40-50 birds on the first full day. Highlights included the first 6 Ruby-throated Hummingbirds of the season, all of them hatch-year birds. It is unclear if they all hatched locally or if they're the first migrants of the fall.

Hatch-year male Ruby-throated Hummingbird

It was a good day for flycatchers. The number of Eastern Wood-Pewees banded each year at Metro Beach varies greatly from zero to a few. This adult was a welcome first.

After hatch-year Eastern Wood-Pewee

Willow Flycatchers nested in the banding area this summer, so it wasn't surprising that a youngster was caught out in the Field Nets.

Hatch-year Willow Flycatcher

A Least Flycatcher was a bit of a surprise as they don't often nest in the park, and had been undetected here since early June. But the most interesting flycatcher was the Eastern Kingbird, which was only the second banded here since 2004 (the first was in spring 2009) and only the third ever.

Hatch-year Eastern Kingbird

Swallows are very difficult to catch in the banding area, as they usually forage above net height, and have excellent vision to avoid getting caught. And most swallows to date have been banded in spring, so the two Northern Rough-winged Swallows in the Field Nets were a real treat. Both were juveniles, as evidenced by the broad cinnamon edgings on their wing coverts.

Hatch-year female Northern Rough-winged Swallow

Of course the fleshy corners of the mouth were another giveaway that they were juveniles. They were both sexed as females based on the lack of "serrations" on the front of the outermost primary.

Hatch-year female Northern Rough-winged Swallow

An adult female Cedar Waxwing was a nice catch, as they aren't banded here every year. She had very limited black on the chin, and a fully developed brood patch.

After hatch-year female Cedar Waxwing

She was soon followed by a hatch-year Cedar Waxwing, easily identified by its streaky breast and short crest, but they cannot be sexed at this stage.

Hatch-year Cedar Waxwing

Yellow Warblers nest commonly in the banding area, but are very early migrants, so it is always interesting to see how many we can catch before they all depart. Typically, the peak of migration is the last week of July or the first week of August. There were a lot of them still around on opening day, but we couldn't get the nets up early enough to catch them. Today, we managed to catch three hatch-years, identified by their generally yellow coloration with a suggestion of an eye ring (somewhat like a Nashville Warbler) and yellow tail spots. Only those with chestnut streaks can be sexed as male; the remainder must be recorded as unknown.

Hatch-year Yellow Warbler

Another warbler that nests in the banding area, but doesn't depart as early, is the Common Yellowthroat. In early August, many are just out of the nest and wearing a briefly-held juvenile plumage that will confound even some experienced birders. The lack of yellow on the throat, along with cinnamon wing bars, are the most confusing characters, and are molted out into more expected patterns by late August. They cannot be sexed when in this juvenile plumage. The individual in the photo below had the shortest tail of all those banded today, but when it flew off it was very strong, just like it had a full-length tail.

Hatch-year (juv.) Common Yellowthroat

A pair of sparrow species also nest in the banding area, with the Song Sparrow being the most common. Both species leave the nest with a fairly nondescript streaked juvenile plumage that can be confused with the other nesting sparrow, the Swamp Sparrow. The hatch-year below has no rufous in its wing coverts and is developing the clear bold malar marks that identifies him as a Song Sparrow.

Hatch-year Song Sparrow

Some years I have resorted to checking the wing formula on some sparrows captured in early August, but that was not necessary on this juvenile Swamp Sparrow as it had a distinctive pattern on the crown and rufous in the wing coverts. It is, however, very similar to a Lincoln's Sparrow which does not nest in this area.

Hatch-year Swamp Sparrow

In keeping with the theme of young birds, this young male Northern Cardinal seems surprised that he blundered into our nets. The bill color is mostly yellow when in the nest and at fledging, but quickly becomes mostly dark gray, which then gradually turns orange through the fall.

Hatch-year male Northern Cardinal

Red-winged Blackbirds nest very commonly in the banding area, but are rarely caught in fall as they seem to only raise one brood and then depart the marshes during mid-July. They seem to prefer foraging in open areas, including agricultural fields, until they migrate south in October and November. It seems like they could raise a second brood in this time, but for some reason they do not. They're a remarkably successful species even so. The hatch-year below is a male, only identifiable by his size. Wing measurements are the most reliable means of sexing young Red-wings though birds that are not full grown can present banders with a puzzle, which I've solved in the past by using the bander's leg gage as a last resort, as males take a larger band size than females. How many birders would pass this individual off as a female?

Hatch-year male Red-winged Blackbird

After a very good spring, Baltimore Orioles were caught in surprising (near record in fact) numbers today. Some were hatch-year as expected, but some were adult females in heavy body molt as they prepare for their early southward migration. Most will be gone by Labor Day, and most years none are banded in fall at Metro Beach.

After hatch-year female Baltimore Oriole

And while some species like the orioles and Yellow Warblers are done nesting and well on their way south, some species like American Goldfinches are still feeding young in the nest (a male Common Yellowthroat was also seen today carrying a fat green caterpillar). Several short-tailed juveniles, like the one in the photo below, were captured and a few adult females with fully developed brood patches were also banded.

Hatch-year female American Goldfinch

Interesting birds observed today included Green Heron, Blue-winged Teal, an early Eastern Phoebe by the Field Nets, and two Blue-gray Gnatcatchers (present all summer).

I would like to thank Stevie, Joan, and Bruce for working so hard to clear net lanes on the 7th, and thanks to Tom, Joan, and Mike for helping process a lot of birds on the first full day on the 10th.

Banding Data
SUNDAY, August 7, 2011
Sunrise (E.S.T.): 5:30
Time Open (E.S.T.): 11:15
Time Closed (E.S.T.): 13:45
Hours Open: 2.50
No. of Nets: 3.25-5.25
Net Hours: 12.125
Temperature (F): 72-82
Cloud Cover: 30-90%
Wind: WSW @ 1-3-7 mph
Barometer: 29.77-29.75
Precipitation: None
No. Banded: 3 (plus 1 released unbanded)
No. of Species: 4
Capture Rate: 33.0 birds per 100 net hours
Volunteers (worked 8.0 hours, 8:00-16:00): Stevie Kuroda, Joan Tisdale, Bruce Watson.

Warbling Vireo - 1
[American Robin - 1 released unbanded]
Common Yellowthroat - 1
Swamp Sparrow - 1

WEDNESDAY, August 10, 2011
Sunrise (E.S.T.): 5:33
Time Open (E.S.T.): 6:00
Time Closed (E.S.T.): 13:45
Hours Open: 7.75
No. of Nets: 4.50-13.50
Net Hours: 96.375
Temperature (F): 66-73
Cloud Cover: 5-70-40%
Wind: WSW-WNW @ 5-7-15 mph
Barometer: 29.70-29.79
Precipitation: None
No. Banded: 84 (plus 10 recaptures and 2 released unbanded)
No. of Species: 18
Capture Rate: 99.6 birds per 100 net hours
Volunteers (worked 10.5 hours, 6:00-16:30): Mike Charlebois, Tom Schlack, Joan Tisdale.

Ruby-throated Hummingbird - 6
Eastern Wood-Pewee - 1
Willow Flycatcher - 1
"Traill's" Flycatcher - 1
Least Flycatcher - 1
Warbling Vireo - 7
Northern Rough-winged Swallow - 2
House Wren - 1
[American Robin - 1 released unbanded]
Cedar Waxwing - 2
Yellow Warbler - 3
Common Yellowthroat - 4 (plus 2 recaptured)
Song Sparrow - 22 (plus 1 recaptured and 1 released unbanded)
Swamp Sparrow - 1 (plus 2 recaptured)
Northern Cardinal - 2
Red-winged Blackbird - 2
Brown-headed Cowbird - 1
Baltimore Oriole - 7 (plus 1 recaptured)
American Goldfinch - 19 (plus 4 recaptured)

1 comment:

Nicole MacP said...

Really enjoyed this post - neat to see the juvenile plumages!