Hybrid Gulls- Larus sp.
First-years : North America
1st-years - click on the links to go directly to the bird
1st-winter larus sp. Roberts Lake, Monterey, California March 2007 : 2 images (above & below)
Putative Glaucous-winged Gull x larus sp.
I'm undecided on this bird.
Structurally and in plumage tone it is very similar to Glaucous-winged Gull (short milky primaries match tertials in colouration and tone) however the wing coverts and scapulars seem to be to strongly barred for a pure Glaucous-winged. The tertials show quite large white tips and notching at the sides of the 'slightly' darker centres.
Other Pro Glaucous-winged Gull features are the deep based bill with pronounced Gonydeal expansion though Western Gull can show a similar shaped bill.
With my limited experience of west coast hybrids this could well be within the acceptable variation of pure Glaucous-winged Gull?
1st-winter larus sp. Roberts Lake, Monterey, California March 2007 : 4 images (above & below)
Probably Western x Glaucous-winged Gull
The primaries and tail are noticeably darker than the tertials and wing coverts whilst the overall tone of the bird is rather 'muddy' indicating a Western Gull influence. The next generation of grey scapulars seem to be to dark for a Glaucous-winged Gull again suggesting Western Gull whilst the general feel of the bird, not dark enough for a Western and to dark for a Glaucous-winged, suggests hybridisation between the two.
The images below taken at slightly different angles show how the affect of light and dark can be altered in relation to where direct sunlight is coming from. The first image below shows perhaps a more matching colour and tone between the primaries and tertials whilst the following image, taken mere seconds later, show the primaries to significantly darker.
There is a replaced darker grey tertial which adds to the contrasting appearance.
Large North America west coast gull are a melting pot of hybrids of various ages and generations with most not being straight forward as one would hope in assigning parentage. Is it a Glaucous-winged Gull at the darker end of the scale to be a genuine bird or is it a hybrid? Is that first-winter dark gull with paler wing-coverts just a variation or is there mixed blood at play. Because of this and the fact I needed two of the gulls for my world gulls list it was major part in me returning to California several times.
I have covered a number of the ages and presumed hybrids in the following pages however as my experience of west coast hybrids is limited to not much more than a few weeks I may be wrong in some of my tentative identifications.
With the exception of the final images in this series all of the following birds are presumed Western x Glaucous-winged Gulls.
1st-winter larus sp. Roberts Lake, Monterey, California 26th November 2009 :
Probable Western x Glaucous-winged Gull
Head, bill and general Jizz would suggest Glaucous-winged Gull however the upper-parts are to dark and to well patterned thus eluding to a hybrid Western x Glaucous-winged Gull.
1st-winter larus sp. Laguna Park, San Luis Obispo, California 23rd November 2009 :
Probable Western x Glaucous-winged Gull
This bird has a more Western Gull jizz than the previous bird however the greater coverts, tertials, scapulars, primaries and tail are to pale indicating this is a Western x Glaucous-winged Gull.
1st-winter larus sp. Salinas River Mouth, Monterey, California 24th November 2009 :
Probable Western x Glaucous-winged Gull
The head, bill and under-parts are as a typical Western Gull however the wing coverts and tertials are strikingly pale with broad whitish fringing. The primaries are dark though with broad whitish tips also give a pale impression. A bird of contrast.
1st-winter larus sp. Salinas River Mouth, Monterey, California 26th November 2009 :
Probable Western x Glaucous-winged Gull
1st-winter larus sp. Roberts Lake, Monterey, California 26th November 2009 :
Probable Western x Glaucous-winged Gull
1st-winter larus sp. Goat Rock Beach, Jenner, California 29th November 2009 :
Probable Western x Glaucous-winged Gull
1st-winter larus sp. Bodega Bay, California 28th November 2009 :
Possible American Herring x Glaucous-winged Gull
The overall pale-mid brown tone alone rules out a pure Glaucous-winged Gull whilst the under-tail barring, general feel of the head and bill and the pale grey fresh scapulars would suggest American Herring x Glaucous-winged Gull.
Western Gull instead of American Herring Gull is a possibility though the feel of the bird does quite fit whilst a pure, darkest end pure Glaucous-winged Gull is again possible but unlikely due to the wing coverts be far to well marked and the tone of the under-parts also to dark.
presumed Western x Glaucous Gull, juvenile: Laguna Park, San Louis Obisp, California, USA - 23rd November 2009
This juvenile bird included here as example of a probable hybrid. The bulbous all black bill, the head shape, the dark head, neck and body tones and well marked wing coverts indicate Western Gull however the juvenile scapulars have whitish fringing giving the bird a slightly 'frosty' appearance above and the primaries, although dark, are not blackish. It is most likely this is a hybrid bird which could be overlooked as a Western based on the darkish body colour.
 Roberts Park Monterey (4).JPG)
 Roberts Lake Monterey (5).JPG)
 Roberts Lake Monterey (5).JPG)
 Roberts Lake Monterey (5).JPG)
 Roberts Lake Monterey (5).JPG)
 Roberts Lake Monterey (5).JPG)