31 December 2018

December 2018 Quiz


Age: The dark carpal bar across the upperwing coverts, and apparent full tail band point to a 1st cycle gull.

Identification: The overall wingtip pattern and carpal bar point to a small tern-like gull (so-called sternine gull). There are only two species in North America that show a complete black trailing edge from the body out to the outermost primary: Black-headed Gull and Bonaparte's Gull. Seeing the bill would've been helpful as the two typically show different bill patterns. But there's something much more obvious that we can use here. Black-headed has considerably more black on the under-primaries, as seen here. The light gray/white pattern on the under primaries on our December Quiz bird are spot on for a 1st cycle Bonaparte's Gull.

Cuyahoga County, Ohio. November. 

28 December 2018

Field Museum Musings - Kodak Gray Scales and Such

A few notes from a visit to Chicago's Field Museum last week.

I'm currently working on a project that requires quite a bit of data collection from both live birds and museum specimens. One component to this data is measuring gray tones. Now a standard for measuring gray colors on the upperparts of gulls, the Kodak Gray Scale has steps 1-19, with 1 essentially being white and 19 black. My objective with measuring these gray tones is to compare them to current values given in the literature. In particular, I would like to verify (or contradict) what has been recorded by previous workers. 

The two specimens below are Western Gulls. The left bird is the paler, northern, race: L.o. occidentalis. The right specimen is the darker, southern, race: L.o. wymani. One challenge is to come up with an "average" for what is seen on the upper mantle (lighter) versus the mid to lower scapulars (usually darker). The other challenge is determining whether there are two noticeable generations of feathers. Newer feathers will generally appear darker (in adults) and older feathers should have suffered from some fading, and hence paler.

For the specimen on the left, I averaged it to be a KGS value of 8.5
For the specimen on the right, I averaged it to be a KGS value of 10





Another long-term project of mine is evaluating Iceland Gull specimens collected from the presumed ranges of the various subspecies during the breeding season. Just for fun, here's a spread of dark-end thayeri, to pale kumlieni. At some point, I'll find some time to post on my progress in this endeavor.



And like most of my visits to any gull collection, I usually find myself distracted by all the toys. Pictured below is a 1st cycle male Great Black-backed Gull (New Brunswick, November) and a 1st cycle male Little Gull (India, September).



A special thanks to Ben Marks for allowing access to the gulls here, again! The staff from the bird division at the Field Museum is an incredible resource.

27 December 2018

Kenosha & Racine Wisconsin - Glaucous x Herrings

A collection of Iceland Gulls from last weekend, with a putative Glaucous x Herring at the end. 
Kenosha & Racine Counties. Wisconsin. 23 December 2018.

1st Cycle Thayer's Gull. 1 of 3.

2 of 3.

3 of 3.

2nd Cycle Thayer's Gull. 

2nd Cycle K-T Iceland Gull.

2nd Cycle Thayer's Gull. 

3rd Cycle type Thayer's Gull.

3rd Cycle type Thayer's Gull.

Adult Thayer's Gull. 

Adult Thayer's Gull.

Adult Thayer's Gull.

Adult Thayer's Gull.

Adult Thayer's Gull (left of center with Herring Gulls). 

1st Cycle Kumlien's Gull. 1 of 4. 

2 of 4.

3 of 4.

4 of 4. 

3rd Cycle type. Kumlien's Gull. 1 of 3. 

2 of 3.

3 of 3. 

Adult Kumlien's Gull. 

Adult K-T Iceland Gull. 

2nd Cycle, Putative, Glaucous x Herring (right of center). 1 of 6.

2 of 6. 

3 of 6.

4 of 6.

5 of 6.

6 of 6.

...perhaps you noticed my favoring photos of birds facing to the left. Cheers!

26 December 2018

Academy of Natural Sciences at Drexel University

A few notable specimens from an impromptu visit to the Academy of Natural Sciences at Drexel University, last week.  The museum is the oldest in the New World, boasting the 8th largest ornithology collection in the world, and 5th largest associated with a university. One of the highlights of my visit was looking over the Kumlien's-Thayer's specimens. Here's an adult type from Ellesmere Island, collected on 19 August 1934 (sex unknown). Skins from Ellesmere Island - presumably from the core of thayeri's range - have been difficult for me to find in the collections I've visited in the last few years.

p8-p10 retained (4th basic?), p7 dropped, p6 growing, p5 almost fully grown. 

The molt here is rather typical for a large gull in mid-August in the northern hemisphere. For what it's worth, the thayeri I see here on Lake Michigan in late October to early November are still molting/growing p9-p10 upon arrival, exhibiting molt migration.
The pigment on p8-p10 on this individual is somewhat extensive and pale. I'm writing this off as a adult type showing some seasonal fading/bleaching. Perhaps some of it is a collections artifact? Further, the p5-p6 subterminal bands were just a hint paler than I was expecting for a Thayer's taken from Ellesmere.

Next up is a presumed nominate fuscus, Lesser Black-backed Gull, from northern Egypt. Most interesting is the size of the p10 mirror (~48mm). This measurement seems to exceed ranges given in the literature. I'd appreciate some comments on this bird.

Lesser Black-backed Gull. 

Same LBBG (left) with Peruvian Kelp Gull (right). 

A special thanks to Jason Weckstein for showing me some of the gulls here!

25 December 2018

Bucks County Pennsylvania CBC

For the last 5 years or so I've had the "Bucks County" CBC on my "to-do" list, intrigued by the thousands of Herrings seen at the Tullytown Landfill. On Saturday, 15 December 2018, I joined George Armistead and Jason Weckstein for a jaw-dropping day at the dump, estimating some 35,000 Herring Gulls for the day.


Tally: 4 Glaucous, 8 Iceland, 25 Lessers, 450 Greats, 600 Ring-billeds, ~35,000 Herring Gulls.

1st Cycle Glaucous with Adult Great Black-backed.

Putative, adult, Lesser Black-backed x Herring Gull. 1 of 6 seen on this day.

Adult Lesser (center) flanked by twin Herring Gulls. 

1st Cycle Great Black-backed Gull, with Adult Herring Gulls.


Yes, in my zone...gull patrol is not for everyone.

01 December 2018

Monthly Notables November 2018

Sightings

  • California Gull (adult). Cameron Parish County, Louisiana. 01 November 2018.
  • Lesser Black-backed Gull (3rd cycle type). Curry County, Oregon. 02 November 2018.
    • 1st County Record. Retained p9-p10.
  • California Gull (1st cycle). Jacksonville, Florida. 07 November 2018.
  • Laughing Gull (1st cycle). Lake County, Indiana. 07 November 2018.
  • Little Gull (adult). Capital District, British Columbia. 07 November 2018.
  • Lesser Black-backed Gull (2nd cycle). Santa Clara County, California. 10 November 2018.
  • Great Black-backed Gull (adult). Pueblo County, Colorado. 10 November 2018.
    • Believed to be the same individual returning for the 25th year!
  • Lesser Black-backed Gull (3rd cycle). San Francisco County, California. 12 November 2018.
    • 1st Farallon Island record. Missing left foot. Likely the same individual seen in San Mateo County in April 2018 (then a 2nd cycle). 
  • California Gull (adult). LaPorte County, Indiana. 12 November 2018.
  • Slaty-backed Gull (adult). Benton County, Washington. 16 November 2018.
  • Glaucous-winged Gull (1st cycle). Larimer County, Colorado. 16 November 2018.
  • Mew Gull (adult). Oklahoma County, Oklahoma. 17 November 2018.
  • Sabine's Gull (2nd cycle). Sarasota County, Florida. 18 November 2018.
  • Lesser Black-backed Gull (2nd cycle). San Francisco County, California. 19 November 2018.
  • Black-legged Kittiwake (1st cycle). Wilson County, Tennessee. 21 November 2018.
  • Black-headed Gull (adult). Georgetown County, South Carolina. 22 November 2018.
  • Common Gull (adult). Essex County, Massachusetts. 24 November 2018.
    • Returning for the third consecutive winter, this individual has a silver band on the right leg, originating from Iceland. No p8 mirror and a broken p5 band. 
  • Slaty-backed Gull (adult). Nipissing County, Ontario. 24 November 2018.
  • Sabine's Gull (1st cycle). Sarasota County, Florida. 24 November 2018.
  • Black-legged Kittiwake (1st cycle). Perry & Faulkner County, Arkansas. 25 November 2018.
  • European Herring Gull (1st cycle). St. John's County, Newfoundland. 25 November 2018.
  • Glaucolus Gull (1st cycle). Madison County, Mississippi. 26 November 2018.
  • Lesser Black-backed Gull (adult). San Diego County, California. 28 November 2018.
    • Retained p8-p10.
  • Black-legged Kittiwake (1st cycle). Clark County, Nevada. 29 November 2018.


Miscellaneous Notes

  1. An estimated 170 Lesser Black-backed Gulls were reported at the Findlay Reservoir in Hancock County, Ohio on 11 November 2018. This count would certainly be a new high record for the Great Lakes region. Observer Jeff Loughman. 
  2. On 15 November 2018, the Seaside City Council in central California approved a permit to have a floating Heermann's Gull nesting island put in place at Roberts Lake. 
  3. Six California Gulls were observed at a water treatment plant in Culberson County, Texas on 24 November 2018. To my knowledge this is a single site high count. Observers Martin Reid, Sheridan Coffey, Willie Sekula.

November 2018 Quiz


Age: We can be sure this individual is not sporting definitive adult plumage. The heavily marked tail, ink spots on the upper side of the secondaries (right wing), black-marked primary coverts, and smoky brown pigment on the under wing coverts along the leading edge (left wing), all make this a relatively straight forward bird to age. It has adult like gray secondaries and primaries, with broad white tips, ruling out a 2nd cycle. This individual would best be aged as a 3rd cycle type if we can agree it's a large, four-year gull.

Identification: The gray upperparts don't appear dark enough for any black-backed species. Which gray-backed gull has pale eyes and a medium size bill? The black subterminal tip to the bill superficially resembles Ring-billed Gull, but our bird has more of a menacing look with a barrel chested-body and broader wings. Of course if we were observing this bird in real life, we'd immediately get a sense for size and structure, but we don't have that information in a single snapshot. However, if it were a Ring-billed, it would be a 2nd cycle as this is a 3 year gull. The tail band is too wide for Ring-billed with black coming up more than half the length of several rectrices. Here's a typical tail band on a 2nd cycle Ring-billed Gull. It helps to zoom in on what look like pink feet (Ring-billed is yellow-footed).

Our November Quiz bird is a 3rd cycle Herring Gull, a species we should be comfortably familiar with anywhere in North America. Ottawa County, Michigan. December.