LBBGxHERG offspring observed……in the Gulf!

This summer I received an interesting observation of a banded gull from Chris McCready,  a wildlife biologist working in Gulf Shores Alabama as a Natural Resource Advisor for the oil spill cleanup operations.  Chris observed a banded sub-adult gull, J06, on July 17 between Gulf Shores and Orange Beach, Alabama.  According to the band color, this bird should be a Herring Gull (up to now, we’ve only used green bands on Herring Gulls and black bands on Great Black-backed Gulls).

Photo by Chris McCready

This is only the second gull we’ve banded at Appledore that has been observed in the Gulf, so it was already a unique observation.

When Chris sent me the photo, I thought the bird’s coloring looked odd for a sub-adult Herring Gull.  In fact, when I quickly looked at the photo, I worried that maybe we’d put a Herring Gull band on a GBBG!  I was in the midst of the field season at the time and was not able to spend much time looking into it further.

Then, on October 11, Marshall Iliff (eBird/Avian Knowledge Network Project Leader at Cornell’s Lab of Ornithology) reported the same bird.

In his email inquiring about whether the bird was banded at Appledore, Marshall said, “This bird looks like a Lesser Black-backed x Herring to me…I was already taking pictures of it from the Dauphin Island Ferry in Alabama when I noticed the green and metal band on the left.  I could not read it in the field, but on the photos the green band seems to read “J06.”  It is a first-summer gull, so hatched in summer 2009.”

In fact, this bird was banded as a chick in July 2009.  When I looked back at our notes from the field, I remembered that we banded a few chicks around the vicinity of the LBBG x HERG nest that year.  We did this because it was difficult to determine which chicks actually belonged to the nest; chicks tend to scatter when they see banders approaching!  The LBBGxHERG nest was obscured by boulders, so it was difficult to observe interactions between chicks and parents after banding the chicks.  We did know that there were two chicks at the nest because there had only been two eggs.  So, we made an educated guess that chicks banded as F04 and F06 were from the LBBGxHERG nest.  However, we had some uncertainty and thought that J06 could be one of the two chicks from the nest.

Marshall’s observation suggests that J06 is one of the two chicks from the LBBG x HERG nest in 2009.  This makes J06 the second LBBG x HERG chick to be observed off Appledore Island (along with F02 hatched in 2008)!

Photo by Marshall Iliff

Full confession here:  I’m much more an ecologist than a birder.  Marshall, however, is an outstanding birder and is into gulls.  So,  I asked him what specific physical characteristics of J06 tipped him off that it was an unusual bird.  He said,

“First-summer Lesser Black-backed Gull is entirely black billed, or maybe with some pale right at the base. This continues well into their second-winter. For first-winter Herring Gull, by contrast, the bill is almost never as dark blackish and develops a pale base by about 6 months of life. In their first-summer I am not sure it is ever normal to see a black-billed Herring–all of them have significant pale at the base.

Added to that, this bird looked distinctly dark above and pale below (and pale-headed). This general pattern is a better match for Lesser Black-backed and whenever I see a Herring type Gull with that pattern, it makes me look twice. Most Herrings are evenly brown (breast, back, belly) in their first-winter (although not all, some are whiter breasted). However, the ones that are truly dark above and white-headed are usually a sign of something interesting, and that’s how this Alabama one looked.”

Many thanks to Chris McCready for sending in his observation of J06 along with photo!  And, kudos to Marshall for his keen eye and for helping solve the mystery surrounding J06!!

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One thought on “LBBGxHERG offspring observed……in the Gulf!

  1. Pingback: C01 and J06 resighted (again!) « The Gulls Of Appledore

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