An old wound: Gull sp from ON, Canada - 2004

[Brandon Holden]

After having my website crash, I've been working on getting old gull images back online. A few days ago, I re-visited a very controversial gull from late December, 2004. It is a bird largely in 1st basic plumage, photos here:

https://picasaweb.google.com/Peregrine1 ... steryGull#

The bird was posted on ID frontiers, and a gauntlet of possibilities were suggested. It was almost a split vote between Great Black-backed Gull, Lesser Black-backed Gull and Yellow-legged Gull. I would be very keen to see if anyone here has any insight on the ID of this bird. I'll post some of my own views and in-field observations below, just in case anyone wants to look at the photos without too much suggestion from myself.

Thanks in advance!

Brandon Holden
Hamilton, Ontario


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My views on the bird:

--- Initially, most people suggested a runt/female Great Black-backed Gull based on the first set of photos (Dec 24). I believe that the very cold temperatures gave the bird a fat & short-winged look in the photos; but with years of studying GBBG's, I am 100% confident that there is no possible way this bird has any GBBG genetics in it. (in the field and post-observation analysis).

--- Although not common like GBBG in our area, it is regular to see 5-10 Lesser Black-backed Gulls per day in Ontario (spring/fall). I actually didn't even suspect LBBG as a true possibility on the first day of observation. The bird gave a wrong "jizz" for the species, and the molt was surprisingly advanced for a 1CY LBBG in our area (more on this below). In the field, I was surprised that the birds bill looked LONGER than 90%+ of the Herring Gulls nearby. Since the observation and years of looking at photos, I can't say I can exclude LBBG as a possibility and seriously wonder if that's what this bird is.

--- Yellow-legged Gull is a bird I have very little experience with (an adult in Newfoundland), and am not really able to comment other than photo research I have done. I have managed to find some photos of birds that are remarkably similar to my bird, like these:

http://www.xs4all.nl/~daarruud/micha/micha1a.html
- 2nd bird down

http://gull-research.org/ylg1cy2cy/1cynov/01cynov.htm
- the main photo on the page - several birds similar to mine - including that unusual head-shape(?) that I don't think I've seen on many other birds of any species here in Ontario.

The main strike against YLGU at the time was the delayed molt (retained juvenile rear scapulars) - but I have often questioned this. Lesser Black-backed Gulls in Ontario always seem to be suprisingly behind on their molt compared to birds photographed in Europe (Juvenile plumage retained well into January or for the entire winter) - and have wondered if the remarkable distance the bird flies to Ontario has wasted enough energy to delay their molt. It would seem like a reasonable explanation to me that the bird suspended it's molt, and would retain the feathers until it began molting in the spring. Thinking like this led me to try and find some sort of plumage feature (other than molt and size) that could help separate YLGU from LBBG, and can find nothing!


So, as one might expect, I'm rather biased towards hoping the bird is a Yellow-legged Gull. The Great Lakes area is a great vagrant trap, and has accepted records of Common Gull and European Herring Gull (specimen), so YLGU wouldn't be beyond the range of possibilities. But I feel I'm probably just in need of a wakeup call. Claims Juv/1st ba. YLGU has really gone crazy in the southern USA, so I'm sorry if this too much

Thanks again!

Brandon

[lou bertalan]

hi brandon!

glad you manage to rebuild your large set of gull pics.
in my eyes your gulls is unfortunately a graellsii type lesser black-backed.

basically i see 4 clear reasons for this:

1. tail pattern: there is merly a soft transition from the broad dark subterminal band to the basal part with strange black vermiculations marks (which are not likely to be found in michahellis), not a clear contrast as in most YLG. r6 pattern is something i haven't seen on any (nominate michahellis) yet. azorean atlantis with generally broader tail band still has a stronger contrast.
2. inner webs to inner primaries are not as pale as in the average michahellis but rather typical for graellsii (extention of pale areas).
3. freshness of plumage. letting apart the lack of 2nd generation coverts which is common in both nominate and atlantis, the state of plumage is just too fresh, juvenile feathers in YLG (as an early breader) usually being much more worn.
4. juvenile lower scapulars - i know that vagrants' moult can get messed up, still i find it hard to believe that the virtually retained juvenile scapulars on a YLG would look like this...

regards,

lou

[JanJ]

Hi Brandon!

A quicky. Here´s the 'Binbrock gull' again, which I saw a few years back and asking about here if you remember?

http://www.surfbirds.com/forum/showthre ... don+holden (now I can´t find that gull in question )

I would say that , if not something else obscure, that LBBG as was my immediate impression the first time I saw the gull. Both structurally, on wing pattern and tail suggest a LBBG type (http://www.gull-research.org/lbbg1cyb/h ... ec1cy.html), which is still my impression.

JanJ

[Brandon Holden]

Hi Brandon!

A quicky. Here´s the 'Binbrock gull' again, which I saw a few years back and asking about here if you remember?

http://www.surfbirds.com/forum/showthre ... don+holden (now I can´t find that gull in question )

I would say that , if not something else obscure, that LBBG as was my immediate impression the first time I saw the gull. Both structurally, on wing pattern and tail suggest a LBBG type (http://www.gull-research.org/lbbg1cyb/h ... ec1cy.html), which is still my impression.

JanJ

Thanks for the comments! I think the main shock came when many people initially thought the bird was a Great Black-backed Gull, and led to a lot of confusion.


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The birds JanJ mentions can be found in this album:

https://picasaweb.google.com/Peregrine1 ... romOntario#

The first 10 photos in the album is the bird I first posted on surfbirds (labeled as bird 1).

The next 5 photos are a bird that was also debated on ID frontiers (labeled as bird 2).

I feel like all of these birds in the album are smith Herring Gulls, but they show a lot of variation not normally shown in the guides.



Thanks again!

Brandon