Bird Hybrids: Glaucous Gull

Showing posts with label Glaucous Gull. Show all posts

Thursday, 14 January 2016

Herring Gull x Glaucous Gull

Herring Gull x Glaucous Gull hybrid, Oulton Broad (Suffolk, UK), January 2013 - copyright Andrew Easton

(photo ID: 2598)

We already have a page for American Herring Gull x Glaucous Gull so good now to have some photos of birds from the other side of the Pond. This first bird looks like it had a long pale-based bill recalling Glaucous Gull and seems to be a lot bigger than the accompanying Herring Gull.

Herring Gull x Glaucous Gull hybrid (same bird as in photo ID 2598 above; behind Herring Gull), Oulton Broad (Suffolk, UK), January 2013 - copyright Andrew Easton

(photo ID: 2599)

The next bird looks subtler to me, though of course I didn't see it in the field.

Herring Gull x Glaucous Gull hybrid, Carlton Colville (Suffolk, UK), December 2015 - copyright Andrew Easton

(photo IDs: 2600-2601)

Personally I find some of the less obvious examples of this hybrid (assuming they are correctly identified) rather tricky to separate from pale Herring Gulls, especially those with bleached primaries. We would welcome discussion on this point - how do you distinguish them?

This one is a scan from an old print...

Herring Gull x Glaucous Gull hybrid, Coppermill Filter Beds, Walthamstow (London, UK), late 1990s - copyright David Darrell-Lambert

(photo ID: 2602)

Herring Gull Larus argentatus
Glaucous Gull Larus hyperboreus

Thursday, 5 June 2014

Glaucous-winged Gull x Glaucous Gull

Glaucous-winged Gull x Glaucous Gull hybrid, Port Townsend, Jefferson County (Washington, USA), 28th October 2011 - copyright Steve Mlodinow

(photo ID: 1371)

Steve points out that the head shape and small eye on this bird are suggestive of Glaucous Gull. The primaries are intermediate, though perhaps more like Glaucous-winged Gull. The pale base to the lower mandible would be abnormal for a pure juvenile Glaucous-winged Gull in October. Steve notes that folded primaries this colour wouldn't be unusual in a Glaucous-winged Gull by mid winter.

Apparently the contrast between the folded primaries and the rest of the wing was more prominent in life than shown in the photo above, but it's more apparent in the blurry flight shots below. The first flight shot isn't blurry though, and Steve highlights the intermediate wing pattern. He points out that the apparent dark grey at base of secondaries is a shadow cast by the greater coverts which have been lifted up by the wind.

Glaucous-winged Gull x Glaucous Gull hybrid (same bird as in photo ID 1371 above), Port Townsend, Jefferson County (Washington, USA), 28th October 2011 - copyright Steve Mlodinow

(photo IDs: 1372-1374)

The next bird is an adult and Steve noted that the wingtip pattern was intermediate between Glaucous-winged and Glaucous Gulls, the back and mantle were paler than Glaucous-winged Gull and the eye was dark.

Glaucous-winged Gull x Glaucous Gull hybrid, about 30 miles off Westport (Washington, USA), April 2008 - copyright Steve Mlodinow

(photo IDs: 1479-1480)

For the next one Steve notes that American Herring Gull x Glaucous-winged Gull should be darker on the wing-tips and would likely have a more obviously pale eye (this bird's is a bit brown) and bicoloured bill.

Glaucous-winged Gull x Glaucous Gull hybrid (the birds in the background are probably Western Gull x Glaucous-winged Gull hybrids), Mukilteo, Snohomish County (Washington, USA), 14th January 2011 - copyright Steve Mlodinow

(photo IDs: 1225-1226)

On the next bird Steve draws attention to the intermediate bill and primaries. To its right is a bird that looks good for a pure adult Glaucous-winged Gull and behind it is a dark immature (partially in frame) that is likely a Western Gull x Glaucous-winged Gull hybrid.

Glaucous-winged Gull x Glaucous Gull hybrid, Cedar River Mouth, Renton, King County (Washington, USA), 30th December 2006 - copyright Steve Mlodinow

(photo ID: 1227)

Glaucous-winged Gull Larus glaucescens
Glaucous Gull Larus hyperboreus

American Herring Gull x Glaucous Gull

American Herring Gull x Glaucous Gull hybrid, Siena Pond, Broomfield County (Colorado, USA), 7th January 2012 - copyright Steve Mlodinow

(photo ID: 1325)

Compared to some North American gull hybrids this one doesn't seem to be so common. Here are some notes from Steve:

"Note the very Glaucous Gull like bill pattern, small eye like a Glaucous Gull, but bill a bit narrower than normal for that species. Most importantly, note wing tips, which are slightly darker than tertials and remainder of wing, more like a Glaucous-winged Gull (which wouldn't have the pink bill, with black tip)."

American Herring Gull x Glaucous Gull hybrid (same bird as in photo ID 1325 above), Siena Pond, Broomfield County (Colorado, USA), 7th January 2012 - copyright Steve Mlodinow

(photo ID: 1324)

Some marvellous shots of the next one:

American Herring Gull x Glaucous Gull hybrid, Sequim, Clallam County (Washington, USA), 8th February 2009 - copyright Steve Mlodinow

(photo IDs: 2221-2223)

Steve says the next one appeared paler in life than the photo would suggest. He adds,

"It had a rather straight, thick, long bill without much of a gonydeal angle... a fairly typical appearance for "Nelson's Gull" in my experience. Note that the primaries are brownish and tipped white, not black. Also, the back is pale gray (paler than that of Ring-billed Gull) with very sparse markings and the wing coverts had the salt and pepper appearance of a Thayer's or Vega (or Glaucous) Gull as opposed to the muddier appearance of a Herring Gull's wing coverts. The bird was also stouter and larger than nearby Herring Gulls."

American Herring Gull x Glaucous Gull hybrid, Pueblo Reservoir, Pueblo County (Colorado, USA), 23rd March 2014 - copyright Steve Mlodinow

(photo ID: 1572)

The next bird was some distance away and was digi-scoped by Steve. He says there are a couple of differences between how it looks in the photo and how it looked in life: the very straight edges to the bill (proximal to gonys) are not as striking as they were in life and the bill looked more bubble-gum pink than yellowish. The body and back colour are portrayed more accurately, including the wingtips which were not that much darker than the body. Steve also notes the flat headed, big-white-eyed look that many Herring Gull x Glaucous Gull hybrids seem to show.

American Herring Gull x Glaucous Gull hybrid, Windsor Lake, Weld County (Colorado, USA), 11th March 2015 - copyright Steve Mlodinow

(photo ID: 2138)

John tells us that the next bird stood out at first because it was so pale and he initially suspected it was a Glaucous Gull. When it took flight he noticed the reduced black in the wing tip (compared with American Herring Gull). It's the second bird from the left.

probable American Herring Gull x Glaucous Gull hybrid (with Great Black-backed Gull, left, and 2 American Herring Gulls, right), Goose Rocks Beach (Maine, USA), 18th October 2016 - copyright John Oates

(photo ID: 2875)

Steve comments on the next third-year bird:

It is hard to capture, in such dingy light, how pale backed this bird appeared. When I first saw it at a distance, I thought it an Iceland Gull. I quickly drove closer, and realized that the primary pattern was off, thought Thayer's Gull. But the bird was distinctly paler than the nearby Ring-billed Gulls. The bird was also large and aggressive, attacking a Common Merganser and stealing its fish. The bill is relatively hefty, with an appearance that I have come to associated with this cross. The only major issue is the eye color (which did look paler in life than in the pics, but not hugely so). The distant pic of the bird on the water is give a feel for what it looked like whence not in flight. The bill looked a bit different in life than in these photos: a bit of red next to the red, and the tip of the bill was also paler than the portion proximal to the band on the bill.