26 October 2014

Banded Adult Herring, LBBG and Thayer's

Northern gulls continue to trickle in on southern Lake Michigan with continued sightings of Lesser Black-backeds and Thayer's Gulls in the second half of October.

Lesser Black-backed (4th cycle type). New Buffalo, Michigan. 25 October 2014.
From the open wing photo, it appears the two outer primaries and visible secondaries are retained 3rd generation feathers, hence this bird would be undergoing its 4th prebasic molt:

P1-P8 are 4th Basic. Renewal of secondaries far from complete.
I had very brief looks at this 1st cycle Thayer's Gull before it picked up and flew out on the lake:

Thayer's Gull (juvenile). New Buffalo, Michigan. 25 October 2014. 
Any day I'm able to find a banded gull - and actually record the entire nine-digit sequence - is a success! Now for today's highlight:

American Herring Gull (adult). New Buffalo, Michigan. 25 October 2014. Band #1106-15613.
It was banded as a chick while too young to fly (14 June 2010) on Chamber Island in Wisconsin.

The red pin is Chamber Island in far north Green Bay, Wisconsin (just a rock's throw from Michigan waters along the south-central border of the UP). 

There's no doubt in my mind that many of the Herrings that breed on the small islands in Door County, Wisconsin, migrate south to New Buffalo, Michigan.

Bill deeply tinged with pink. Is this a reliable mark that suggests a "young" adult Herring? Do older adults show this?

P9 two-thirds grown (no mirror). P10 one-third grown (relatively small mirror). Note the "fake" mirror at the base of P9.

No sub-adult markings on primary coverts, alula or tail. P5 with full subterminal band.

Banded Herring (left). 4th cycle type LBBG and adult type Herring (right).

P5-P7 with insignificant white tongue tips.

Of course the lighting on the water was harsh. This was the best upperwing shot I could manage. 

20 October 2014

First of The Season Thayer's

Saturday, 18-Oct-2014, was our first notable gull movement here on the south rim of Lake Michigan. We tallied 8 species at the Miller Beach Lakewatch, with Thayer's Gull and Laughing Gull being the most interesting larids.

Lakewatches are fun...even in the rain.

Birders tallied 4 Thayer's Gulls, which is apparently an Indiana state "day" high count for October.

Juvenile Thayer's with Ring-billed Gulls. Gary, IN. 18 OCT 2014.
Decent numbers of Herrings were streaming by (mainly from east to west), with the occasional black-backed species and Franklin's mixed in. A species that's become tougher to detect on southern Lake Michigan is Laughing Gull. I'd estimate that roughly 1 is seen on the lakefront for every 10 or so being seen inland these days. So it was a nice treat to have a 1st cycle come down the beach over the breakers, just 5 minutes after a couple of similar-aged Franklin's were seen cruising by:

Franklin's (top). Laughing (bottom).
Photos heavily cropped and lightened.
 Down on the beach a 2nd cycle and 1st cycle Lesser Black-backed came in to feed:

LBBG (1st cycle). Gary, IN. 18 OCT 2014.
To end our day, I was joined by visiting California gull enthusiasts, Noah Arthur, in New Buffalo for a couple of more hours of gull study. Highlights here were 2 Great Black-backeds (1st cycle and 2nd cycle):

GBBG (1st cycle). New Buffalo, MI. 18 OCT 2014.

GBBG (2nd cycle). New Buffalo, MI. 18 OCT 2014.
Much to my surprsie we saw zero LBBGs or white-wingers, but we found plenty of interesting Herrings for Noah to conjecture about - birds with much bigger bodies and lighter-marked primaries than he's used to seeing out West:
Herring Gull (adult type). New Buffalo, MI. 18 OCT 2014.
Slaty-colored wingtip with relatively extensive white pattern.
Another Herring that got Noah's attention was this 1st cycle with an old-world tail pattern:

I've seen Smith's with limited pigmentation up the outer tail feathers, but this one is really pushing the limits! 

All in all, it was an adrenaline-producing day and a fine way to get the season rollin'!

Another Not A Most Wanted Poster

This one probably won't be as popular as the adult version, but here's another collage of 15 species. All are in their 1st plumage cycles. All occur in North America. I'm looking forward to your comments. Enjoy!

18 October 2014

Two Hatch Year Herrings

I found this gorgeous juvenile American Herring last weekend that has now been put on my "Top 10" juvenile HERG sightings (I really do keep such a list for several common species):

Herring Gull (1st cycle). New Buffalo, MI. 12 Oct 2014.
Aside from the petite bill (which might not be done growing) and crisp upperwing coverts, the tertials have a striking pattern to them. The visible pale notches along the tips and ribbed-effect along the tertial edges is not found in the majority of individuals. The primary tips show small pale tips (not uncommon in HY Herrings) which contrast nicely with the entire bird.

Can you count the tertials on the right side? 
Now compare this other HY Herring that was photographed a few moments later on the same stretch of beach:

Herring Gull (1st cycle). New Buffalo, MI. 12 Oct 2014.

This individual is rather worn and bleached for mid-October, but the condition of its plumage is not uncommon for many of the HERGs that are thought to have hatched locally in the Great Lakes region. The former Herring above might be suspected of hatching later in the season at a more northern latitude, but one can't be entirely sure. 

Here are the two together:

The worn Herring on the bottom looks like it was put on "high-cycle" in a washer and left to dry
under the hot Texas sunlight on a warm afternoon.

13 October 2014

More Gull Specimens From Chicago's Field Museum

I again had the pleasure of looking through the gull collection at Chicago's Field Museum last Friday. The most interesting specimen studied during my visit was this first cycle bird:

Monterey County, CA. March 1909.
It was identified as a California Gull (L.californicus), but the bill's pattern and shape didn't seem consistent with that species. I also felt the lack of post-juvenile scapulars seemed wrong for a 1st cycle California Gull in March. Herring Gull crossed my mind but the uppertail coverts and outer tail edges didn't agree with Herring. I left the specimen alone and wasn't comfortable labeling it. Thanks to Steve Hampton and Tristan McKee - both gull aficionados from California - for steering me in the right direction on this one and suggesting "Western Gull" (which I fully agree with). Here are Tristan's comments regarding the scapulars:

"...looks just like a March Western. The small size is probably a preparation thing. My impression is that ALL the juvenile scaps have been replaced, as expected. Western's preformative molt is so early that the feathers come in quite young-looking".

Given that it was collected in Central California in March is another reason to believe it's indeed a Western.
The last few days have been very educational for me as several people have cautioned me on the condition of old specimens housed in museums. In particular, taxidermist Keith Mueller had many useful comments to make that were taken to heart:

"Be careful about relying on bill and tarsii measurements on any Taxidermy mount (unless an cast artificial head is used) especially very old skins whether full mounted or drawer skins. These dried skins can dry and shrivel so varied that it would be impossible to gauge the extent or the shrinkage and distortion, and for that matter, color fading. Even plumage coloration fading and handling wear can be completely different than the actual color values. I have been a Taxidermist since 1974 and have seen s o much variation in fading and distorted bare parts, actually this info is almost useless in relation to reality."

"Amar, the colors can do just about anything as the bill dries. I have seen a few lighten up, but mostly they get darker and often turn blotchy and uneven."

"A skin that is that old will be subject to quite a bit of degradation through time, especially if they are not cared for properly. Markings can change also when the feather texture degrades giving a false optic as to the actual shapes and forms of the markings. Evaluating study skins can be challenging with all these factors taken into consideration. The best approach I have found is to compare a drawer skin to an actual photograph and make your conclusion that way."

"When a skin is prepared for a drawer skin, how the "inside" of the skull is handled will also change the shape of the skull and bill. The concept behind drawer skins is to prepare the skin so it can be examined, referenced and researched for time."

It's becoming clearer to me that size measurements and bare part colors from old skins - perpared decades ago - are to be carefully considered, especially if no in-field experience is tied to these values. This makes the measurements taken from live birds (such as those found on gullresearch.org) much more meaningful. I wonder what implications this has on measurements found in the literature, specifically our gull guides.

Other interesting specimens from this visit include a leucistic 2nd cycle type Laughing Gull:

New Jersey. Early June.
The faded hood feathers are interesting - this might be a consequence of long-term feather deterioration exhibited by old skins, or a result of this bird's leucism. Notice the complete fading of the bill color! This is a clear example of a dark bare-part color becoming light, just as a light bare part color may become darker when housed over a long period of time.

There are lots of other interesting skins that I saw during this visit and I'll eventually get around to posting all or most of them with comments, but for now, I'll finish with a set of four folded wingtips, from darkest to lightest. Care to guess what species these are? The answers are posted below.

The two on the left were identified as Thayer's Gulls (Alaska and British Columbia) and the two on the right as Iceland Gulls (Nova Scotia). The third bird was actually collected by Earl Godfrey.

08 October 2014

Not A Most Wanted Poster, But...

I put this collage together, just for fun, knowing all of my gull-inclined readers would get a kick out of it.

Feel free to give it a go and see if you can identify these individuals. They're all adults and they all occur in North America. Answers below.

Row 1: Kumlien's (Iceland) Gull, Slaty-backed Gull, Glaucous-winged Gull.
Row 2: Ring-billed Gull, Bonaparte's Gull, Laughing Gull.
Row 3: Herring Gull, Lesser Black-backed Gull, Black-headed Gull.
Row 4: Mew Gull, California Gull, Glaucous Gull.
Row 5: Thayer's (Iceland) Gull, Western Gull, Great Black-backed Gull

05 October 2014

A Note on Upperpart Color Variation in HY Ring-billed Gulls

I think it's fairly safe to say that adult Ring-billeds don't deviate from the Kodak Gray values that they've been assigned in the literature (KG value 4-5), but what about sub-adults, particularly hatch year birds?

Hatch Year Ring-billeds. Slightly darker scapulars shown by the individual on the left.
I'm most confident that post-juvenile scapulars on HY Ring-billeds do vary in color tones. I believe this to be primarily a result of these feathers not being "entirely" gray, showing a random mix of brown hues (on dark birds) and white hues (on pale birds).

Left bird shows slightly paler scapulars with whiter hues, while the individual on the right has browner hues.

These differences can be nearly impossible to detect under bright sunglight, and as always, observers should choose overcast days to accurately evaluate grays. Notice how the gulls in my photos aren't casting any shadows onto the ground - a good indication that the lighting is neutral, or mostly neutral.

The variation in upperpart "hues" on these two individuals should be noticeable.
Aside from gray, these post-juvenile scapulars show a mix of grown centers and white edges. These cololrs surely influence how the eye perceives the gray colors on HY birds.
A good example of a "pale" HY Ring-billed. This individual shows silvery-white hues on the post-juvenile scapulars. 

If it was later in the season, the pale gray on the individual above might be attributed to "bleaching", but being this early in the season, my guess is that there's actually very little bleaching - if any - that has affected these feathers. Further, it would seem that individuals with paler upperwing coverts would have paler scapulars, and individuals with more solidly brown upperwing coverts are more likley to show these darker scaps.

Perhaps this caveat also applies to other gull species - American Herring Gull being the first example that comes to mind. I've long suspected that sub-adult Herrings (3rd and 4th cycle types) can show slightly darker grays, and my explanation for this has long been that some of these birds show an excess amount of underlying brown tones within their gray feathers. More to come on this in an upcoming post...

04 October 2014

Three Herrings and a [Dead] Fish

It's not uncommon to find Herring Gulls feeding on dead fish along the Illinois, Lake Michigan lakefront, especially in the Fall season. Below is a series of photos taken at 63rd Street Beach on 01 Ocotober 2014.

When I arrived at the beach this adult was feeding:

Close by were two younger birds - a second cycle and a hatch year bird - patiently waiting their turn to feed. Somehow the HY bird snuck in after the adult, and this seemed to disobey any hierarchy-of-feeding code, if such a thing exists with gulls:
But not for long. The 2nd cycle almost instantly moved in and flexed its muscles:
They locked bills for about 30 seconds...
 ...a little tugging and splashing...
 ...and even an unfair wing-lock from the 2nd cycle...can you predict the victor?
The older and more experienced gull definitely won this short scuffle and proceeded to claim its booty:

A couple of comments on plumage features from this set: the adult type has relatively large p10 mirrors (p9 dropped here), but I've come to accept this as "variation at the species level" that's perfectly okay for individuals on southern Lake Michigan. Whether this is age-related or not remains unknown with American Smiths.

The 1st cycle has almost completely replaced all of its juvenile scapulars which is just a tad more advanced than what I've been seeing for the last couple of weeks in Michigan City and New Buffalo, but still, completely expected for this region.

The relatively large pale tips to the newly grown primaries on the 2nd cycle bird are the boldest they'll appear all season. Here's a better look at the open wing:

The white tips will soon start to wear down as the season progresses and will likely be unnoticeable by the end of winter.