15-22 May 2011
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All maps, charts, text & photos © Hilton Pond Center


We can't help but pay attention to American Goldfinches (AMGO) at Hilton Pond Center. They're exceptionally colorful--especially when males don their bright breeding attire each spring--and they're entertaining in their antics at thistle socks we hang at our feeding stations (above). Although we've written about goldfinches on several occasions, encounters with an especially old one--plus a distant recapture--prompted us to write this week about "American Goldfinches Revisited--And Revisiting."

All maps, charts, text & photos © Hilton Pond Center

Click on image above to view a larger chart in a new browser window

We've gotten intimately familiar with American Goldfinches, Carduelis tristis, through the years--mostly because they've become the second-most-commonly banded species at the Center since we started our long-term natural history research in the Summer of 1982. As of this week we've handled 8,299 AMGO (see chart above)--exceeded only by 8,452 House Finches (HOFI). With the steady decline of local HOFI in the past decade, we anticipate goldfinches will rise to the top of the list in the next year or so--unless the upcoming winter brings a big influx of Purple Finches (currently #3).

All maps, charts, text & photos © Hilton Pond Center

Click on image above to view a larger chart in a new browser window

As noted by the rising red trend line on the chart just above, American Goldfinches are indeed on the increase at Hilton Pond Center. Except for the late-1980s and mid-1990s when we were away from the Center for all or most winters, we've typically banded at least 200 AMGO per year, with an annual average of 277 for the 30-year period. In three of those years we handled more than 500 goldfinches--and likely will do so in 2011--while in 2007 we had an amazing all-time high of 838. We're not sure what happened last year with a near-record low of 127 AMGO, but it may have had to do in part with our taking citizen scientists for hummingbird research in Central America while many goldfinches were feasting on thistle and sunflower seeds around Hilton Pond.

All maps, charts, text & photos © Hilton Pond Center

One trend that doesn't show on our charts is a significant increase in the number of American Goldfinches we're now seeing at the Center during the breeding season. Historically, AMGO descended in late fall into the Carolina Piedmont, mostly as migrants from the species' primary breeding grounds in the northeastern and north central states. (See USGS map above, on which greatest breeding density is indicated by darker shades of red.) Goldfinch nesting had been reported from scattered locales in the South Carolina Upstate but the area was not known to host a substantial breeding population; furthermore, most of our Hilton Pond AMGO departed by mid-April for more northerly nesting grounds.

All maps, charts, text & photos © Hilton Pond Center

Even though a map from South Carolina's Breeding Bird Atlas (above)--last updated in 1995--shows no confirmed goldfinch breeding records for York County in which Hilton Pond is located, over the past decade we've captured more and more midsummer American Goldfinch females with well-developed incubation patches; we've also banded increasing numbers of recent fledglings. Likewise, it's no longer uncommon to see a whole family of goldfinches visiting our seed feeders in late August or early September--well before the anticipated arrival of any fall migrants from up north. It certainly appears that American Goldfinches might be expanding their breeding range in the Palmetto State or at least concentrating breeding numbers in the Piedmont, so we'd be quite interested in hearing about nesting records in South Carolina Lowcountry counties that are unmarked on the map above. (Also please let us know if you get a photographable nest within York County in 2011 or thereafter; send your comments to INFO.)

All maps, charts, text & photos © Hilton Pond Center

Although it would have been unusual 20 years ago to see American Goldfinches in mid- or late May at Hilton Pond Center, they were certainly here this week when we banded three males and two females. We also trapped one male (above) that was already banded.

All maps, charts, text & photos © Hilton Pond Center

This bird's aluminum band was rather worn with dirty numerals (above)--sure signs he hadn't acquired the band very recently. As we brought the goldfinch to the banding table in the Center's old farmhouse we were eager to check our records for his number (2290-67480) and had to go back further than we expected--all the way to 20 April 2005. Curiously, we had caught him in the very same trap as a second-year bird and now he is classified as seventh-year. This isn't a longevity record for the species--the federal Bird Banding Lab lists an ancient female American Goldfinch that was 10 years 5 months when found dead--but it's certainly the oldest AMGO we've had at Hilton Pond. A further check of our data revealed we had recaptured this bird twice before on 20 February 2006 and again on 17 April 2009.

All maps, charts, text & photos © Hilton Pond Center

To be honest, had this particular goldfinch not been banded we might not have aged it accurately. As shown in the photo above, he hadn't quite completed his molt into breeding plumage--note the olive-gray feathers on the nape--and his epaulets were not the bright yellow edged in white we would expect in a bird at least three years old.

All maps, charts, text & photos © Hilton Pond Center

One way banders determine age in male American Goldfinches is by looking at the birds' shoulders. If an epaulet is "salt and pepper" with a mix of black and yellow and white feathers (above), the bird is considered to be "young" (either hatch-year or second-year). American Goldfinch males don't typically go from "salt and pepper" to yellow on the shoulder until they are "after second-year," i.e., in their third calendar year. Thus, #2290-67480 was a tad confusing with his "intermediate" epaulet, but even without the band to confirm age we--in the end--would have recorded him as being a "full adult."

And while we're talking about recaptures of "old" birds, we must admit we've been remiss in relaying the news that some American Goldfinches banded at Hilton Pond Center have been encountered elsewhere. One of those--a second-year male banded as #2590-32702 on 7 January this year was found dead on February 11 about five miles southwest of the Center by Max Overcash. This was the fourth of our banded AMGO to be recovered and reported from within our home county of York since 1982. Of much greater significance, however, was another goldfinch (#2510-94792) found far from Hilton Pond.

All maps, charts, text & photos © Hilton Pond Center

The American Goldfinch in question was banded on 21 January 2009 at Hilton Pond Center, when we classified it as a midwinter second-year male that hatched in 2007 at some unknown location. The next year on 10 March 2010 this same bird was re-trapped by Jim Gruber at Chestertown MD (see map above)--a little more than 400 miles northeast of York SC. Jim bands on Maryland's Eastern Shore at Foreman's Branch Bird Observatory, recently merged with Washington College's Center for Environment & Society. This particular bird was only our fifth American Goldfinch out of more than 8,000 to be reported beyond York County, the others being recaptured and released at Albion NY (650 miles from Hilton Pond) or found dead at Dryden NY (580 miles), Shortsville NY (590 miles), and Rumford ME (870 miles). With the exception of the Chestertown bird, all were encountered from very late April through early September, implying their breeding grounds were probably up north rather than here in South Carolina. It's interesting that three of the five AMGO came from locales so close together in New York State.

It's always fulfilling to hear of our locally banded birds that show up elsewhere, but for several reasons we were particularly pleased with Jim Gruber's report. For one, #2510-94792 was released after recapture and is liable to show up again. In addition, the bird provided data for TWO research stations, with Hilton Pond Center learning where one of our goldfinches went TO and Jim Gruber discovering where one of his came FROM. And, in an interesting coincidence, the historic colonial village of Chestertown MD where Jim Gruber bands and caught our bird happens to be the home of Juli and Glenn Dulmage (right)--old friends (by now) who were citizen scientists on two of our hummingbird expeditions to Costa Rica and Belize. What's more, Jim Gruber heard Juli and Glenn speak to a local bird club about their Belize experience AND Juli and Glenn actually visited Hilton Pond several years ago--not knowing the route they traveled from Chestertown MD via car eventually would be duplicated in reverse by a migratory American Goldfinch who made the trip back north under his own power. Amazing birds, these goldfinches, whether revisited or revisiting.

POSTSCRIPT: It appears the account above of an American Goldfinch banded in January 2009 at Hilton Pond Center and recaptured and released a year later (March 2010) at Chestertown MD was posted a little too soon. Based on a note we received on 5 June 2011 from the U.S. federal Bird Banding Laboratory, we learned that Jim Gruber actually had recaptured TWO of our goldfinches, the latest one a second-year female banded at the Center on 19 April of this year and caught again at Chestertown just this week on 22 May. We're not sure what the odds are of banding two American Goldfinches at the same Carolina Piedmont site and then having them show up more than 400 miles away at the same research station in Maryland, but they're probably pretty slim.

All maps, charts, text & photos © Hilton Pond Center

The Piedmont Naturalist, Volume 1 (1986)--long out-of-print--has been re-published by author Bill Hilton Jr. as an e-Book downloadable to read on your iPad, iPhone, Nook, Kindle, or desktop computer. Click on the image at left for information about ordering. All proceeds benefit education, research, and conservation work of Hilton Pond Center for Piedmont Natural History.

"This Week at Hilton Pond" is written & photographed by Bill Hilton Jr., executive director of Hilton Pond Center for Piedmont Natural History.

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15-22 May 2011

Yellow-throated Warbler--1 *
Carolina Chickadee--3
American Goldfinch--5
Downy Woodpecker--1
House Finch--12

* = New species for 2011

5 species
22 individuals

19 species
1,405 individuals

(since 28 June 1982, during which time 170 species have been observed on or over the property)
125 species (30-yr avg = 66.7)
56,282 individuals
(30-yr avg = 1,876)

(with original banding date, sex, and current age):
American Goldfinch (1)
04/20/05--7th year male (see essay above)

Operation RubyThroat has teamed with EarthTrek so citizen scientists--like YOU--can contribute observations about hummingbird migration and nesting behavior. Membership is free for this great new opportunity to help increase scientific understanding of Ruby-throated Hummingbirds. Data entry forms for 2010-11 are on-line, so please register today at EarthTrek.

NOW is the time to report your 2010 RTHU fall departure dates for the U.S. & Canada, and fall arrival dates for Mexico & Central America.
Please participate.

--Spring rains continue at Hilton Pond Center, with 5.05" accumulating this month; 2.6" of that fell on 16-17 May. The pond itself is looking better than it has in more than a year--only about 8" shy of being full--although recent storms have roiled the waters.

--A recently fledged Red-shouldered Hawk has taken to sitting on top of one of our Wood Duck boxes on Hilton Pond. The ducklings are already gone, so it's likely the big bird isn't looking for an easy lunch. Maybe the raptor just likes that particular perch as it looks for tasty frogs and small mammals along the pond margin.

--The second-year female Yellow-throated Warbler captured on 18 May was only the ninth of her species banded at Hilton Pond Center since 1982 and the first since 2006; her well-developed brood patch indicated she must be a local breeder. We captured her in a hanging sunflower seed trap that, oddly enough, was open and not set to catch birds. She eventually would have escaped on her own but we got to the trap quickly and had her in-hand.

--We regret this year's spring banding efforts at Hilton Pond Center were greatly restricted by back-to-back bouts of strep throat and a severe upper respiratory infection. Unable to run mist nets from late April through late May, we undoubtedly missed many migrants that moved through the Carolina Piedmont. (Of this month's 22 banded birds, all but three were trapped on 22 May.)

--If you're intrigued by our account of American Goldfinches in the photo essay above, tables showing all birds banded at Hilton Pond and encountered elsewhere are at York County Encounters & Foreign Encounters.

All text & photos © Hilton Pond Center

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Hilton Pond Center for Piedmont Natural History is a non-profit research, conservation & education organization in York, South Carolina USA; phone (803) 684-5852. Directed by Bill Hilton Jr., aka "The Piedmont Naturalist," it is parent organization for Operation RubyThroat. Web site contents--including text and photos--may NOT be duplicated, modified, or used in any way except with express written permission of Hilton Pond Center. All rights reserved worldwide. To request permission for use or for further assistance, please contact Webmaster.