27 June 2014

Another Mystery Gull

Well perhaps not a mystery gull, this 1st cycle bird from Sheboygan, Wisconsin may be a very pale graellsii Lesser Black-backed, but Ethan Gyllenhall and I were convinced we'd found a hybrid Herring x Lesser Black-backed as we watched it in the field:

1st Cycle LWHG. Sheboygan, WI. 08 June 2014.
It had just as much, if not more, white in the scapulars than most of the similar-aged Herrings. This, along with the notably pale gray tones were unlike any 1st summer LBBG I've seen. The paling bill, which is not completely unheard of in 1st summer LBBGs, also gave us pause. And what's up with the paling eye? I suppose all of this is possible in a one-year old graellsii, but...

Width and pattern of tailband, and renewed rectrices not typical of LBBG.
Pale sliver notch on subterminal portion of the outer web of P3 not typical of LBBG.
A semi-translucent quality to the underside of the primaries and secondaries is odd for LBBG.

This bird somewhat reminds me of the known-age, known-provenance, 2nd cycle LBBG X HERG found by Blair Nikula back in December 2009 in Cape Cod. 

Green F02 is the offspring of the famous Green F05 LBBG that was paired up with an American Herring Gull on Appledore Island. Here it is shown with one of its chicks, Green F07, from a subsequent brood:


There's no doubt that there's an increasing presence of gulls that appear intermediate between LBBG and HERG in the United States. Some remain skeptical of this hybrid combination, but for the time, I see no better explanation. The primary identification challenge is eliminating Yellow-legged Gull (or vice versa, depending on your perspective). I do feel LBBG x HERG is a much more likely explanation, and seeing that this combination has already been documented right under our nose, we may already be at the stage where we're seeing F2 and F3 hybrids and backcrosses with American Herrings.

24 June 2014

Lake Michigan Season High Count of Little Gulls

On Friday, 13 June 2014, I recorded eleven Little Gulls in Manitowoc, Wisconsin. One group held 9 birds in a single flock, while 2 other birds were in view. This sighting constitutes a personal species high-count for me, and is likely the greatest number of Little Gulls recorded on Lake Michigan since the early 1990s.

Here are a few of the more cooperative individuals:

LIGU (1st summer). Manitowoc, WI. 13 June 2014.

A short video of the 9 LIGUs in one flock:

Other weekend highlights included more Lesser Black-backeds (14) and my first June Grerat Black-backeds (5) of the year. All of the LBBGs were 1st/2nd cycles and all of the GBBGs were 1st cycles. The theme of course is sub-adult birds that are presumably spending their summer south of the breeding grounds (or west of the breeding grounds when considering GBBGs?). Also of note was 3 more LIGUs in Sheboygan, for a total of 14 in two days.

Interestingly, we missed GBBG last weekend which would've given us a 9 gull day. Others had a Glaucous Gull on this day in Port Washington, for at least "ten" gull species on the Wisconsin lakefront in June!!

GBBG (1st summer). Two Rivers, WI. 14 June 2014.
LBBG (1st summer) with RBGU (front) and HERG (back). Two Rivers, WI.
GBBG (1st summer) with RBGUs (1st summers). Two Rivers, WI. 14 June 2014.
Two Rivers, WI. North of the rivers. Some 1,200 LWHGs.
1st summer LIGU. Sheboygan, WI. 14 June 2014.
Advanced 2nd summer LBBG. Sheboygan, WI. 14 June 2014. 1 of 3.

1st summer LBBG. Sheboygan, WI. 14 June 2014. Same bird below.

1st summer BOGU with nearly complete hood. Sheboygan, WI.  14 June 2014.

Who says you can't watch gulls in the summer??? :)

11 June 2014

More Wisconsin Gulls - June

The Wisconsin lakefront is quickly becoming my favorite summertime gulling locale. This past weekend, I was joined by both Ethan Gyllenhall and Alex Hale for what turned out to be an 8-species day. We covered Manitowoc, Sheboygan and Port Washington.

Manitowoc provided us with a 1st summer Little Gull with a half-hood. Amazingly, Charles Sontag observed 7 here the day after.

Little Gull (1st cycle). Manitowoc, WI. 08 June 2014.
Sheboygan was absolutely amazing! We enjoyed a fully-hooded 1st summer Little Gull (the bird I reported a couple of weeks prior from Manitowoc, click here for photos of that bird). Other goodies included a 9 Lesser Black-backeds (six 1st cycles, one 2nd cycle, two 3rd cycles). No adult LBBGs were found as is expected in the summer months.

Lesser Black-backed Gull (1st cycle). Sheboygan, WI. 08 June 2014.
Ethan quickly picked out this bleached Thayer's/Kumlien's type off the Municipal Beach that is just north of Deland Park. This stretch of beach holds hundreds of loafing gulls throughout the summer.

Likely a Thayer's Gull (1st cycle). 08 June 2014. Sheboygan, WI. 
Knowing whether this is a Thayer's or Kumlien's is anyones guess, but we did get to see the open wing and the bird showed a contrasting secondary bar, a relatively bold tail band and darker outer webs to the outer primaries:

We finished the day off at Port Washington where we picked up an adult Laughing Gull and a 3rd cycle Lesser Black-backed. We tried chumming this bird but to no avail. It's amazing to see what little interest the Ring-billeds and Herrings show in handouts here - much different than birds found in the inner-city.

07 June 2014

Northern-type American Herring Nesting on Lower Lake Michigan

I had the good pleasure of joining Indiana birder and conservationist, Carolyn Marsh, and an associate of hers to a waterbird colony on private property in East Chicago, Indiana, last weekend. The highlight for me was finding a Northern-type American Herring Gull on a nest:

Subject bird, lower right, sitting on nest. East Chicago, Indiana. 01 June 2014.
 The surprise came when this individual got up and opened its wings:
Note the large mirrors on both outer primaries and gray inner webs to P7-P9.
Showing a pseudo-thayeri pattern, this bird's outer primaries are atypical for breeding Great Lakes Herrings.
American Herring Gulls exhibit a tremendous amount of variation, particularly in their wingtip patterns. Generally speaking, "western" birds show more extensive black in the outer primaries and more often show a single mirror on the outermost primary. It's also thought that these birds are overall smaller. "Eastern" adults tend to show less black on the outer primaries, average two mirrors, and are thought to be bigger-bodied. Some of this geographic variation was briefly touched on by Mactavish and Jonnson (Birder's Journal, 2000), but the comparisons made were between so-called Newfoundland birds and Great Lakes birds. The samples were quite small and no in-hand measurements were made. In short, the paper was non-exhaustive, and many of the notes come from wintering birds. 

Currently, there is no agreement on what to call these "populations" because they haven't been described in much detail. Some of the suggested "types" being tossed around include: Northern, Eastern, Newfoundland, Western, Great Lakes, Southern, and Interior...

In a recent discussion on the FB Group, North American Gulls, Alvaro Jaramillo raised these questions:
"If you go north and east from the Great Lakes, where do you think the morphology changes from Great Lakes birds to Eastern/Northern birds? Is it a gradual shift, or do you think there are major breaks somewhere? Where hypothetically are these breaks? Shift from forest breeders to tundra breeders in the north? "

Admittedly, very little has been published on what North American Herrings look like at their breeding colonies throughout the continent. This is a longterm project for anyone who is eager to contribute information on the most widespread, large white-headed, pink-legged, gull species in North America. After seeing this individual, I've begun to rethink what so-called Great Lakes birds really look like. Although this individual is certainly out of the ordinary for us down here, I'm wondering if there are more birds like this nesting on the Great Lakes. Perhaps it's time to closely scrutinize these breeders. 

The most difficult questions to answer will be, 1) Are mirrors age/gender related, or, are there truly differences from east/west and north/south? 2) Is the amount of black in the wingtip age/gender related, or, are there truly differences from east/west and north/south? These questions are nearly impossible to answer without study of, and monitoring of, birds banded as pullus. Other important details that can be sorted out with time, are vocalization differences and morphometrics.  

Nest of Northern-type American Herring.
Other, more typical, nesters from the day:

Describing what various populations of American Herring Gulls look like can be done, but it will take effort. It's my hope that bird banders consider using large, color, bands; Many biologists and ornithologists have already begun using these in North America but we have a long way to go. Also, methodically photographing these birds where they're nesting is just as important. A database of photos should be compiled, and an "average archetype" from each participating region should be suggested and put to the test. 

As always, I welcome your thoughts and comments! Thanks.