eBird and the Gray-hooded Gull

By Team eBird August 4, 2011
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Gray-hooded Gull (front) with Laughing Gulls at Coney Island. Photo by Mark Szantyr.

The avian sensation of the summer surely has been the Gray-hooded Gull (Chroicocephalus cirrocephalus) at Coney Island, Brooklyn, New York, with even the New York Times reporting on this exciting rarity. First spotted 24 July, word finally reached the birding community 28 July and by the next afternoon the bird had been relocated, but only a lucky few got to see it before it disappeared that day. Shortly after being relocated at noon on Saturday, it seemed to have settled into a predictable routine and birders began arriving by the dozens to see this rare visitor. But the story of this bird’s identification is perhaps the most interesting part; read on to find out more.

eBird has revolutionized birding in a number of ways, but one of those is the speed at which information is exchanged and the level of scrutiny that reports are getting worldwide. Ten years ago, this exceptional occurrence of Gray-hooded Gull in New York might have slipped through the cracks, or might have come to light months or years after the fact. But thankfully the story this time is quite different!

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Fig. 1. Not your average rare bird location, and not your average “seagull”; even at a distance the distinctive upperwing pattern and extensively dark underwing can be seen.

On 24 July, Jacob McCartney and Sara Burch visited Coney Island and noticed an unusual gull among the Laughing Gulls. Since Gray-hooded Gull isn’t even in most North American field guides, and since the wing pattern, eye color, head color, back color, and other features clearly indicated that this bird was not a Laughing Gull, they reached the reasonable conclusion that it was a Black-headed Gull. Black-headed Gull is quite a rarity in summer, with just a handful of records for mid-summer on the Northeast coast, so when they reported it, eBird’s filters did their job by flagging the record for review. The New York eBird data reviewer for Kings and Queen Counties (including Brooklyn), Doug Gochfeld, immediately noticed the record and followed up with a request for documentation. He received a response quickly with a photo attached (see below) and–noting the white eye and gray hood–realized that it was a good candidate for Gray-hooded Gull.

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Fig. 2. The photo that started it all! Sara Burch got this image with her iPhone to document her sighting, and it set the birding hotlines reeling once word got out that it was a potential Gray-hooded Gull.

Although the back of the bird appears unusually dark in this original photo, others that Doug sent the photo to agreed, and by the next day local birders had been mobilized to try and relocate it. At about 6:00 p.m. on Friday, 29 July, the bird had been relocated and confirmed with superb photos, but it didn’t stay long enough for many others to see it. However, it was relocated around noon Saturday, and many dozens made it down to see it over the weekend, despite the Coney Island crowds. And it has been a sensation ever since!

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Fig. 3. The Gray-hooded Gull is actually visible amid the throngs of beach-goers here. It is the first bird on the left sitting atop the tall sign to the right of Ruby’s Bar and Grill!

The best part of this story is just how well the eBird system worked in this case. Jacob and Sara were confronted with an amazing rarity, made a tentative identification, and reported it to eBird; the state reviewer was able to quickly contact them and share photos with others to confirm the ID; local birders were able to quickly mobilize to relocate it; and once the word spread, visiting birders have been able to better document the plumage, molt and feather condition, behavior, and length of stay of this exceptional rarity. Without the internet and the community of eBird users interacting with expert reviewers, the story arc might have crawled along much more slowly (if at all), and this exciting bird might have been gone before it was even identified conclusively.

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Fig. 4. In addition to the more obvious field marks, such as the whitish eye, grayish hood with a dark posterior margin, and reddish bill and legs, note the wingtip pattern. The folded wingtips extending past the tail have trapezoidal spots just shy of the wingtip, which is not shown by Laughing Gull.

Gray-hooded Gull has an odd distribution split between sub-Saharan Africa and the Southern Cone of South America. Although South American birds have strayed to Panama a few times, the Coney Island record is just the second for the United States; the first was photographed at Apalachicola, Florida, 26 December 1998, and is fully discussed in this article. We don’t yet know the provenance of this bird (Africa or South America), and the possibility of a ship-assisted bird (this area is a major shipping port, obviously) or even escaped captive is sure to be debated. But given the pattern of other South American gulls reaching the USA (including Kelp Gull, Belcher’s Gull, and Swallow-tailed Gull), many seem to believe that this bird could have arrived under its own power.

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Fig. 5. Gray-hooded Gull at Coney Island — an unusual background for this native of Africa and South America!

This mega-rarity provides a great metric for the levels of eBird use. Although there was not a single North American record of Gray-hooded Gull in eBird prior to 24 July 2011, there have been 64 records submitted since 29 July. (Historical records for Florida and Panama also have been added to round out the global range map for Gray-hooded Gull.)

Good luck to those who go search for it, thanks to everyone involved with the discovery, identification, and documentation of this bird, and please keep those eBird reports coming!

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Fig. 6. In flight, the unique wing pattern of this bird really stands out; no other North American gull has the combination of gray mantle, white crescent, black wingtips, and white subapical spots.

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