04 September 2017

Swallow-tailed Gull Twitch

On Thursday, 31 August 2017, Ryan Merrill found an adult Swallow-tailed Gull at Carkeek Park in north Seattle, Washington (King County). The internet went nuts and it didn't take long before dozens of birders descended on the beach to observe this rarity - only the 3rd to be recorded in North America, and certainly the farthest north the species has ever been observed. The gull spent the entire day on the beach with a flock of California Gulls, with intermittent bouts nearby in the water. It was still being seen at sunset, and surely it would be here the next morning. Or would it?

I closely monitored reports for the next 24-36 hours and just about gave up on my plans when the bird wasn't found the next day. That is, until it was relocated around 5:00 pm local time, roughly 7 miles to the north at Richmond Beach, adjacent to an oil refinery. This site is a tad north of the King-Snohomish County line, putting the bird in a new county and adding excitement for local birders. I locked in with flight & rental car reservations and left Chicago at 6:00 am the next morning. I knew there was a good chance the bird wouldn't be found on the 3rd day, and I was perfectly okay taking that chance (read sweaty palms).

A short 4-hour plane ride from Chicago to Seattle.
When my plane landed, I received the reports every birder dreads on a twitch like this: "No bird today". All negative reports from every channel. Crap. Driving north through a more-than-ever congested Seattle on Labor Day weekend didn't ease my worries. That was valuable time I could've used looking for the gull. I finally got up to Kayu Kayu Park after a 1.5 hour commute from the airport to Point wells. I walked out to the oil tanks with much anticipation.
The walk from Kayu Kayu Ac Park to Point Wells is a mile, back and forth.

I found no bird and no other birders here after spending nearly two hours at the refinery. After comng up empty-handed, I made the seemingly long walk back to the car. This was Seattle's hottest day of the summer, yet, 88F. As I passed Kayu Kayu from the RR tracks, I met Dave Irons who was scoping from the park proper. His wife Shawneen was resting in the car as the two had left their home at 4:00 am from Portland. We chatted for a bit and properly exchanged numbers.

I drove north for about 15 minutes to check the marina in Edmonds. I spent over an hour walking around this busy site, resenting the fact so many weekend-goers were out. If the gull did have any taste for resting here, the masses of fishermen and boaters would surely drive it off. The long breakwall there was loaded with gulls and so I took a break to photograph a few Glaucous-winged x Western hybrids and briefly forgot my reason for traveling to Puget Sound.

Just as it was really beginning to look bleak, I received a message from John Puschock at 4:26 pm: It's in Everett. Everett is approximately 20 miles to the north of Edmonds. John and I were talking the night before and he was confident the bird was in the area feeding on squid. His evidence was convincing, with links to fishing reports that showed good squid fishing in the Edmonds area for the last 6 weeks. This variable shouldn't be underestimated as squid is a primary food source in this species' diet. Paying it forward, I immediately called Dave and Shawneen and alerted them. I cleared the estimated 35 minute trip up to Everett in 25 minutes.

When I arrived, I found Shelley Rutkin and Philip Dickinson - two very lucky birders who spotted the gull at Everett Marina - and a couple of other birders standing with scopes and binoculars. They were looking at a group of gulls in the water. The gulls were close. Very close. I pulled up to them "drive-thru" style, raised my binoculars, and there sat the Swallow-tailed Gull about 100 feet out in the water!

Lifer from the car! Swallow-tailed Gull with Glaucous-winged Gulls. Snohomish County, WA. 02 September 2017.

Now I'm not sure what possessed this bird to do what it did next. But less than 2 minutes after me pulling up (I have the time stamps on my images to verify this), the gull got up and flew straight in, landing no more than 20 feet in front of my car along the edge of the parking lot. Without any time to compose myself, I fired off a few shots as it flew by...

Probably more than any birder I know, I've had my share of chumming in gulls (a couple of Black-tailed Gulls and several Slaty-backeds being on my A-list). But this bird was 100% "unchummed". It sat in front of us and put on the most spectacular show I could've hoped for. With perfect lighting and the sun to our back, it began picking up pebbles with its bill, hock-sitting, flapping its wings as if it were just learning how to use them, and occasionally winking at us as it preened. According to my camera, these magical moments lasted for a little over 7 minutes.

The white crescent under the red orbital is only visible when the bird squints or closes its eye.

It was oblivious to our presence...

The largest eye of any gull species -- befitting for a bird completely evolved to nocturnality.

If you're still reading this report, then you surely deserve to see a few more photos...

As more and more birders soon arrived, and boaters continued to pass through with their trucks and trailers, the bird wisely picked up and returned to the water.

Although the upperwing pattern is reminiscent of Sabine's Gull, the black on the primary coverts is limited and never reaches the gray along the wrist.

With all flight feathers intact, it isn't adjusted to a molt schedule similar to our northern larids. This should suggest it hasn't been in the northern hemisphere long. 

Right then as it flew off, I knew that was the closest I'd get to that gull - ever! I lazily backed off and turned my attention to the growing number of birders.

31 August 2017

Monthly Notables August 2017

  • Heermann's Gull (adult). Imperial County, California. 02 August 2017.
  • Lesser Black-backed Gull (2nd cycle). Imperial County, California. 02 August 2017.
  • Little Gull (1st summer). Niagara County, Ontario. 03 August 2017.
    • A high count of 17 individuals, primarily 1st summers with a couple of adults. Numbers building all summer. 
  • Laughing Gull (1st summer). Sept-Rivières County, Quebec. 03 August 2017.
  • Lesser Black-backed Gull (3rd cycle type). Cass County, North Dakota. 05 August 2017.
  • Sabine's Gull (adult). Los Angeles County, California. 10 August 2017.
  • Little Gull (juveniles). Kiowa County, Colorado. 13 August 2017.
    • High count of 7 individuals in one view. 
  • Mew Gull (adult type). Loveland County, Colorado. 14 August 2017.
    • 2nd consecutive year the species has been recorded in north-central Colorado in August.
  • Franklin's Gull (adult type). Suffolk County, New York. 14 August 2017.
  • Sabine's Gull (adult). Fremont County, Wyoming. 16 August 2017.
  • Sabine's Gull (adult & juvenile). Barnstable County, Massachusetts. 19 August 2017.
  • Lesser Black-backed Gull (2nd cycle). Mason County, Illinois. 19 August 2017.
  • Great Black-backed Gull (adult type). Sweetwater County, Wyoming. 21 August 2017.
  • Great Black-backed Gull (juvenile). Ottawa County, Michigan. 24 August 2017.
    • Although sub-adults regularly summer here, this brilliantly fresh juvenile is curious. 
  • Sabine's Gull (juvenile). Travis County, Texas. 27 August 2017.
  • California Gull (Adult). Bristol County, Massachusetts. 31 August 2017.
  • SWALLOW-TAILED GULL (ADULT). King County, Washington. 31 August 2017.
    • Mega. First state record for Washington.

Miscellaneous Notes:
  1. Topping the list of notes this month is the adult Swallow-tailed Gull found on the last day of the month. With only two previous ABA records (both from California), this Seattle, Washington sighting now constitutes the northernmost occurrence in the world. The bird spent most of the day loafing on the beach with California Gulls at Carkeek Park. 
  2. Juvenile Heermann's Gulls appeared to have bounced back, approaching close-to-normal numbers this season. 
  3. Miami-Dade County had up to 13 summering Lesser Black-backed Gulls this month - these are lower numbers than the last Augusts. As we're seeing everywhere with this species, summer numbers are inconsistent from year to year.
  4. The putative Chandeleur Gull from southern Lake Michigan is back a bit early this season, spotted in Berrien County, Michigan on 26 August 2017.
  5. The high count of 7 juvenile Little Gulls recorded in Kiowa County, Colorado is intriguing to say the least. This early push of young birds, well west of the Mississippi River, suggests the species may be extending its breeding range on the North American continent.

August 2017 Quiz

This neat duo appears to be about half way done with primary molt. Thus, we can safely assume these estival plumage aspects were captured in the midst of the breeding season. The smaller bird on the left has a complete dark trailing edge to the secondaries and a complete tail band - a typical 1st summer "small gull". The larger and darker gull on the right also has vestiges of brown secondaries and retained 1st generation outer primaries - also indicative of a bird in its 1st summer.

The paler bird on the left has a tern-like bill and complete black trailing edge. The light gray upperparts and black ear-spot point to Bonaparte's Gull.

The larger bird with darker gray upperparts has a blunt bill that is proportionately large. Note how significant the bill shape and size is, as well as the shade of gray, when identifying these two. The black post-ocular smudge on the larger bird also hints at a hooded species. Its long pointed hand seems perfectly in line with Laughing Gull, and that's what it is indeed.

This 1st summer Bonaparte's and Laughing Gull are roughly a year old, and are assumed to be nonbreeders. Both birds are undergoing their 2nd prebasic molts Cape Cod, Massachusetts. July. 

01 August 2017

Monthly Notables July 2017

  • Iceland Gull (1st summer). Suffolk County, New York. 01 July 2017.
  • Glaucous-winged Gull (1st summer). Riverside County, California. 03 July 2017.
  • Black-headed Gull (1st summer). Wheatly, Ontario. 08 July 2017.
  • Laughing Gull (1st summer). Kiowa County, Colorado. 09 July 2017.
  • Black-legged Kittiwake (1st summer). Toronto, Ontario. 13 July 2017.
  • California Gull (3rd summer type). Sheboygan County, Wisconsin. 14 July 2017.
    • 2nd summer record for state.
  • Franklin's Gull (1st summer type). Essex County, Massachusetts. 20 July 2017.
  • Great Black-backed Gull (adult type). LaPorte County, Indiana. 20 July 2017.
  • Franklin's Gull (adult type). Eddy County, New Mexico. 23 July 2017.
  • Mew Gull (adult). Cascade County, Montana. 23 July 2017.
  • Ring-billed Gull (adult). Skagway-Hoonah-Angoon County, Alaska. 24 July 2017.
  • Laughing Gull (adult). Notre Dame Bay-Lewisporte County, Newfoundland. 27 July 2017.

1. A Great Lakes high count of 69 Lesser Black-backed Gulls was recorded in Sheboygan, Wisconsin on 14 July 2017. This site (North Point) has seen an increase in numbers of this species in the last 4 years, with mostly 1st and 2nd summer individuals present. This is a seasonal phenomenon brought on by a short bout of dying alewives near shore. No definitive adults present.
2. Multiple juvenile Heermann's Gulls were reported along the California coast this month with a high of 34 individuals in San Mateo County on 28 July 2017.

July 2017 Quiz

Age: The plain wing coverts, admixture of adult-like gray scapulars, single adult-like upper tertial and rounded primary tips all suggest a 2nd cycle type large gull.

Identification: The smudgy head, neck and breast appearance is reminiscent of Glaucous-winged Gull. The "muddy" plumage aspect to the upperparts is as if the bird was powdered with soot. Retaining a largely dark bill into 2nd cycle is also quite common for many Glaucous-wingeds. The only feature on this bird that raises some suspicion as to whether it may be a "pure" Glaucous-winged, is the paling iris. Most Glaucous-wingeds retain a dark eye, but some exceptional birds take on a pale eye (usually as they age, and not quite this young).

It helps to know that this bird was photographed in Grays Harbor, Washington. December. There is a large chance of some Western Gull genes at play, with a smaller chance of Herring Gull involvement. The very dark primaries may be viewed by some as a blocker for Glaucous-winged, but I don't see them as a problem for a bird with such closely matching tertials and greater coverts.

For what it's worth, here's what would be "safely" identified as a "classic" 2nd cycle Glaucous-winged. Seattle, Washington. January.

At any rate, we will settle for Glaucous-winged Gull for our July Quiz, with the unverifiable chance of some outside influence.

15 July 2017

Sheboygan California Gull

Yesterday, I was joined by Ethan Gyllenhall for my July, Wisconsin lakefront run. We found 8 species in Sheboygan, with the highlight being a CALIFORNIA GULL.

3rd cycle type California Gull. Sheboygan County, Wisconsin. 14 July 2017.
Perhaps a 2nd summer record for the state(?).

We also found an all-time Lake Michigan high of 69 Lesser Black-backed Gulls. We opined there must be well over 70 birds but chose to follow a strict protocol with our count.

1st summer Lesser Black-backed Gull. Sheboygan County, Wisconsin. 14 July 2017.

As usual, the majority of Lessers here are 1st and 2nd summer individuals, but for the first time ever, I had more than a handful of 4th cycle types. This leads me to an obvious conclusion - birds that have summered here for the last 3-4 years are now returning and they're being joined by younger cohorts.

3rd summer (now in it's 4th plumage cycle) Lesser Black-backed Gull.
Sheboygan County, Wisconsin. 14 July 2017.

I asked Amy Kearns this morning, how long before a few decide to nest in a nearby Herring colony, and her response was an astute, "If they aren't already"! By the way, Amy (a Biologist living in Indiana) had 50+ Lessers here earlier in the week. She seems to be much more enthralled by this phenomenon than most other birders. To put this event in perspective, no other place on the Great Lakes has seen this many Lesser Black-backed Gulls at one site, at one time. Ever. In fact, no place away from the Atlantic coast has recorded such summer numbers for the entire continent!

Just as interesting is to have lingering Glaucous Gulls on Lake Michigan in July. These birds should be waaaaay north of here at this time of year. We had this beast and a paler 2nd summer type.

First summer Glaucous Gull. Sheboygan County, Wisconsin. 14 July 2017.

First summer Glaucous Gull. Sheboygan County, Wisconsin. 14 July 2017.
A final bird of note here is a 1st summer type Franklin's Gull (different than the bird seen here in May & early June). We missed Laughing (seen by Amy a few days ago) and had zero Little Gulls (despite 500+ Bonaparte's littered about the beaches).

02 July 2017

The Post-Thayer's Era

And so Thayer's Gull has at long last been put to rest. The AOS (AOU) Committee on Classification and Nomenclature has voted unanimously on the proposal to lump thayeri with Iceland Gull (2017-C-7) .

The question was not so much whether there was an irrevocable need to retire the species altogether. Rather, the matter of contention was that there was never sufficient evidence to recognize the Iceland Gulls (nominate glaucoides, kumlieni and thayeri) as unique "biological" forms. I could not agree more. Whether we call all 3 taxa Iceland Gulls or any other suitable English name is inconsequential - so long as they're regarded as conspecifics in the present.

First cycle Thayer's [Iceland] Gull (L.g. thayeri). Waukegan, Illinois. December.

The overwhelming majority of birders alive today, including myself, have always known Thayer's Gull as a species. Witnessing a taxonomic lump of this magnitude is, without doubt, sobering.

Yet, how many of us were never aware that the decision to give Thayer's species status in 1973 was based largely on false pretenses? How many of us don't realize that thayeri has never been systematically described throughout its breeding range? How many birders still don't know of the multiple accounts that describe pale-winged and dark-winged birds purportedly interbreeding in several regions across arctic Canada? Add to this the fact that virtually zero amount of genetic work has been done in order to better understand these 3 similarly-behaving taxa, and it becomes clear that this lump was imminent!

An intermediate thayeri-kumlieni type that I prefer not to stubbornly label.
Michigan City, Indiana. January.

An intermediate adult thayeri-kumlieni type. Whiting, Indiana. February.

How is it, then, that anyone would be satisfied with checking off a "species" cloaked with so much ambiguity!? But I digress. This post isn't to argue the merits of lumping thayeri with the Iceland Gulls - that battle has already been fought and won (you can read my detailed opinion on this subject in a post I wrote earlier this year, Thayer's the Iceland Gull - One Species. Also, see my commentary on the recent proposal in Birding, June 2017. V49 N3).

First cycle Kumlien's [Iceland] Gull (L.g. kumlieni). Whiting, Indiana. December.

Adult Kumlien's [Iceland] Gull (L.g. kumlieni). Hammond, Indiana. February.


Moving Forward

I'd like to suggest that this classification will give fresh impetus to gull-watching and gull study in North America. Gone are the days where circular reasoning is permitted when discussing these forms. Intermediate and perplexing individuals will be called just that, with no impulse to pretend we understand their absolute pedigree. Rightfully, a hefty burden of proof is placed on any contemporary worker who attempts to untangle this complex.

Iceland Gull (L.g. glaucoides). First Cycle. Volusia County, Florida. January.

It's my hope that we'll build on the current identification papers at our disposal, and maybe, just maybe, a few brilliant students of ornithology will eventually get up to the breeding grounds and carefully study these high arctic denizens. At the very least, perhaps increased banding efforts, the use of GPS tracking and the collection of blood samples will be carried out throughout the wintering grounds, for starters.

All is not Lost

The omission of Thayer's Gull from our "checklists" doesn't any more or less change reality. Over the last couple of days, I've read remarks on social media such as, "Great, now I can stop looking for them", as if the task of finding a Thayer's Gull is similar to finding a mythical dragon. 'Tis not.

Adult-type Thayer's [Iceland] Gull. Lake County, Illinois. February.

There will still be a sizable population of dark-winged birds that we will systematically identify as Thayer's [Iceland] Gulls come this Fall/Winter. The only difference is, now, we can enjoy the inherent variation found in this complex without illogical consequences.  

01 July 2017

Monthly Notables June 2017

  • Thayer's Iceland Gull (1st cycle). Gambell, Alaska. 01 June 2017.
  • Franklin's Gull (2nd cycle type). Barnstable County, Massachusetts. 02 June 2017.
  • Western Gull (adult). Sitka, Alaska. 02 June 2017.
    • First Summer Record.
  • Franklin's Gull (adult). Sitka, Alaska. 02 June 2017.
    • First Summer Record.
  • Black-headed Gull (2nd cycle). Northumberland County, Ontario. 04 June 2017.
  • Herring Gull (1st cycle). St. John's County, Newfoundland. 05 June 2017.
    • Apparent European Herring Gull. All flight feathers intact.
  • Common Gull (1st cycle). St. John's County, Newfoundland. 05 June 2017.
  • Lesser Black-backed Gull (2nd cycle type). Clay County, Minnesota. 05 June 2017.
    • First county record.
  • Thayer's Iceland Gull (2nd cycle). Manitowoc County, Wisconsin. 05 June 2017.
  • Ivory Gull (1st cycle). Nome County, Alaska. 07 June 2017.
  • Ross's Gull (1st cycle). Nome County, Alaska. 07 June 2017.
  • Black-headed Gull (1st cycle). Nome County, Alaska. 07 June 2017.
  • Franklin's Gull (adult). Barnstable County, Massachusetts. 07 June 2017.
    • A different individual than that seen on 02 June 2017.
  • Glaucous Gull (3rd cycle type). Pinellas County, Florida. 09 June 2017.
  • Black-tailed Gull (1st summer). Nome Census Area, Alaska. 13 June 2017.
  • Laughing Gull (1st summer). Kearny County, Kansas. 16 June 2017.
    • First County Record.
  • Sabine's Gull (adult). Adams County, Washington. 16 June 2017.
  • California Gull (adult). Churchill & Manitoba County, Manitoba. 16 June 2017.
  • Little Gull (2nd cycle). St. Clair County, Michigan. 22 June 2017.

10 Species Day-list:
Manitowoc County, Wisconsin. 05 June 2017.
Nome County, Alaska. 07 June 2017.
Barnstable County, Massachusetts. 07 June 2017.
Churchill & Manitoba County, Manitoba. 16 June 2017.

Most notable this month is Thayer's Gull losing species rank with the AOS (28 June 2017). This taxon is now one of 3 subspecies of the Iceland Gull, Larus glaucoides thayeri.

Two adult Bonaparte's Gulls were observed near a gull colony in Raudasandur, Iceland. The observers report aggressive displays and flights, and hinted that the species is most likely nesting at the site. As of this summary (01 July 2017) no nest has been reported.

It appears Heermann's Gull has suffered another poor breeding season on Isla Rasa, Baja California. Over 100 adults were observed as far north as Vancouver by mid-June. Thus far only 3 juveniles have been reported this season. Observers are encouraged to carefully report ages seen in the field. One question to ponder is whether the number of 2nd cycle type birds has decreased - this may be an indirect way to census the previous year's young.

A dozen or so Lesser Black-backed Gulls - primarily subadults - spent the month scattered about the interior of the continent. Although this steady increase of summering Lessers is somewhat expected, the distribution is random and fragmented from year to year (most likely associated with available food sources).

An apparent Chandeleur Gull (American Herring x Kelp) was photographed on the Mississippi Gulf Coast on 21 June 2017. Plumage characteristics suggest a 4th cycle type.

30 June 2017

June 2017 Quiz

Age: The largely dark brown wing coverts and substantial tail-band suggest a 1st cycle gull.

Identification: This is a hooded species with obvious eye-crescents. The dark-gray mantle and scapular feathers eliminate paler species such as Bonaparte's, Little and Sabine's Gull. Although not discernable from this single photo, the bill and body size should aid in the elimination process when observed in the field. The only reasonable choices for this 1st cycle gull are Franklin's and Laughing.

This month's quiz bird is a rather typical 1st winter Laughing Gull, photographed in Volusia County, Florida. January.

For comparison, consider this 1st cycle Franklin's Gull. Illinois. September.

First cycle Franklin's show a silvery gray wash across the greater coverts - and perhaps diagnostic - white outer edges to the outermost rectrices. Overall, this species will show whiter underparts and hindeck earlier in the season than Laughing. Finally, Franklin's will often show a much more demarcated semi-hood and wider eye crescents than similar-age Laughing Gulls.

06 June 2017

Bonaparte's Are Fast - Peregrine's Are Faster!

We often see Peregrine Falcons buzzing flocks of gulls and then half-heartedly aborting and changing their intent for reasons unknown to us. Yesterday while wedged between two large boulders on the Manitowoc lakefront, I patiently sat for almost 3 hours admiring a few Little Gulls in a sizable feeding flock of 500+ Bonaparte's Gulls. Suddenly, ALL of the birds took to the air and headed east over the lake in unison. The birds moved with such urgency that I knew the only predator that can elicit such fear is a Peregrine Falcon. Not wanting to be discovered, I remained still and didn't raise my gaze. A few seconds later the falcon zipped right past me, some 75 feet out, and snatched a 1st cycle bird in midair as it tried to gain altitude. I had a fleeting thought it might be a Little Gull, but that wasn't the case.

This one-year old Bonaparte's was a couple of seconds too slow.

01 June 2017

Monthly Notables May 2017

  • Black-tailed Gull (adult). Kitimat-Stikine County, British Columbia. 04 May 2017.
  • Slaty-backed Gull (3rd cycle). Lambton County, Ontario. 06 May 2017.
    • This individual, presumably seen on the Thunder Bay CBC in January 2017, then in Muskegon, Michigan in April 2017, was resighted just outside of Sarnia, Ontario near the St. Clair River.
  • Black-headed Gul (1st cycle). Erie County, Ohio. 10 May 2017.
  • Slaty-backed Gull (adult). Chippewa County, Michigan. 19 May 2017.
  • Black-tailed Gull (2nd cycle type). San Francisco County, California. 23 May 2017.
  • Ivory Gull (adult).  Bonavista/Trinity-Clarenville County, NF & Labrador. 23 May 2017.

May 2017 Quiz

Age: All 3 birds are in high molt, with a mixture of old and new upperparts. The visible primaries on the rightmost and leftmost birds appear to be 1st generation (note the primaries on the center bird aren't visible). Thus, it's safe to say these large white-headed gulls are roughly 1 year of age.

Identification: Both individuals with bi-colored bills look like typical 1st summer Herrings - size and structure rule out smaller species such as Ring-billed, and the thick bills and heavy chests seem to rule out California Gull. The left bird - with a mostly black bill and attenuated look to the rear - is different.

Here's a slightly underexposed image of this individual:

The upperparts are genuinely dark with dark centers. Note the bill is relatively long, but straight, ending with a slight droop. The striated neck markings, and dark stippled tips to the new wing coverts, recall Lesser Black-backed Gull, and that's what this month's gull was identified as.

This first summer Lesser was photographed in Sheboygan, Wisconsin. June.

29 May 2017

First Basic Outer Tail Feathers on Bonaparte's Gulls

A quick note on 1st cycle Bonaparte's and their tail bands. Specifically, what is the pattern on the outer rectrix (R6)? Does the blackish band extend onto the outermost feathers? Seems like a simple question.

In their account on "juveniles", Olsen & Larsson describe T6 (=R6) as being white with white tips. But in the "first summer" account, they imply the outer tail feather does have black markings. This is somewhat confusing and should be clarified.

First cycle Bonaparte's Gull. R6 apparently white. The tail band on this individual doesn't extend onto the outermost tail feathers. Cleveland, Ohio. November.

Howell & Dunn, however, note that some pigment is found on the outer tail feathers, but limited to the inner webs.

As described in Gulls of the Americas, this individual shows some black on both outer tail feathers, but the pigment is limited to the inner web. Evanston, Illinois. April.

Looking through tens of 1st cycles in my photo collections, I mostly agree with Howell & Dunn, that on average, when there is black on the outer tail feathers (which is rather common), the black is generally limited to the inner web. But not always. Some individuals clearly show pigment beyond the feather shaft.

First cycle Bonaparte's Gull with pigment on R6. The pigment crosses over the feather shaft and onto the outer web on the left R6. New Buffalo, Michigan. September.

Interestingly, when viewing the ventral side of the tail on those individuals with pigment on R6, it usually appears there's more pigment from below than above. This, I suspect, is mainly because the inner webs of the outermost tail feathers are more visible when viewed from underneath. From above, the outer webs are more exposed.

Left R6 shows a substantial amount of pigment. Manitowoc, Wisconsin. May.
Although the pigment spills onto the outer web of R6, it doesn't reach the outermost edge of the feather. Chicago, Illinois. November.

As I've found with 1st basic Franklin's, Black-legged Kittiwakes, Little and Laughing Gull, the pigment on the outermost tail feather appears to be more variable than generally thought. I suspect the same might hold for other species such as Sabine's and Black-headed Gull.

27 May 2017

Wisconsin May Run

Late spring through early summer often brings good gull diversity on the Wisconsin, Lake Michigan lakefront. Here, I can often find a few straggling northern species along with hooded migrants. Last Sunday was a great demonstration of this phenomenon with 10 species between Port Washington, Sheboygan and Manitowoc. Couple this with hundreds of sub-adult Herrings in high molt and the hours spent here are well worth any gull-watcher's time and effort.

The highlight for me was this hyper-melanistic 1st cycle Bonaparte's. I've seen 5 or 6 of these now, with this bird being the most cooperative. Although they're reported annually, these types are rare enough to make one do a double-take.

Possibly a 1st alternate Franklin's where all primaries are renewed
in the first plumage cycle (via PA1).

First cycle Lesser Black-backed (1st summer).

Second cycle Lesser Black-backed Gull (1st summer).
Inner-primary molt signals PB2 has commenced.

Second cycle Great Black-backed Gull (1st summer).

Putative 2nd cycle Glaucous x Herring (1st summer). Photo 1 of 2.

Putative Glaucous x Herring. Photo 2 of 2.

Second cycle Thayer's Iceland Gull (1st summer). Photo 1 of 2.

2nd cycle Thayer's Gull with what appears to be a similar-aged Herring Gull.
Of interest is what appear to be adult-like tips to the 2nd generation (?) primaries coming
in on the Herring. Whether or not the Herring is a 1st summer bird is uncertain. Nonetheless,
I do have suspicions that 2nd basic primaries on some of our Herrings can appear adult-like.

1st summer Kumlien's Iceland Gull. Primary molt has likely begun
but no open wing was observed.

This 1st summer Glaucous Gull tried to go unnoticed but it's difficult to that when you tower over
everything around you. First summer Lesser Black-backed in the background