Iceland Gulls - Ageing two birds

My thanks to Les Bird for kindly supplying these images, you can see more of them at http://cuckmereousebirdblog.wordpress.com/  These two birds are present at Newhaven Harbour, East Sussex, the photos were taken on 23 January 2012.

(Iceland Gull - © Les Bird 2012)

(Iceland Gull - © Les Bird 2012)

(Iceland Gull - © Les Bird 2012)

This bird was aged as a second-winter, but is a pale individual. The light eye and pale bill, with an approximately 30-40% black tip, are good pointers to rule out first winter. The lack of strong patterning also rules out most first-winters, but some very pale ones can also look this bleached, and as mentioned above this bird is paler than the average second-winter. Second-winter birds also typically look slightly more brutish than first-winters, the pale eye giving them an expression more similar to Herring Gull, I find first-winters can have more of a cute, Common Gull-like expression. However, the rounder head and fairly slender, long-winged shape, plus their smaller size by comparison, means a second-winter glauciodes is still a lot less brutish than hyberboreus in any plumage.

(Iceland Gull - © Les Bird 2012)

(Iceland Gull - © Les Bird 2012)

This bird is an easy first-winter. The ratio of black:pale on the bill is greater than the second-winter above, and the dark eye gives it that cute, docile look reminiscent of Common Gull. The brownish patterning on the mantle, coverts and tertials is typical of first-winter Iceland Gull and, rather than being at the pale end of the glauciodes spectrum, this is a fairly average bird.

Separation from Glaucous is fairly straightforward. The wings look longer, extending beyond the tail, and the bill is shorter, weaker and less hooked than Glaucous. Iceland has a rounder head and larger eyes, with a deep breast and short legs when standing. In flight Iceland is more elegant, handling strong winds as well as a Kittiwake, and is proportionately longer-winged than Glaucous. Seen side-by side, or with other gulls, Iceland is normally slightly smaller than Herring Gull, while Glaucous is larger than Herring, almost approaching the size of a Great Black-back Gull.

And if you want to separate these two from Kumlien's, the flight shots of the second-winter bird show no grey colouring in the primaries, and the first-winter bird has both a bi-coloured bill and very pale primaries. This should probably rule out about 99% of the hybrid swarm, but please don't ask me to write about the 1% that are inseparable from Ice Gull, I still enjoy gulls at the moment!

Glaucous Gull (larus hyperboreus) - Hartlepool Headland - February 2012 - John Bridges

Here are some imaged far better than my own of one of two Glaucous Gulls (larus hyperboreus) present at Hartlepool Headland in Durham (Cleveland) at the present time. I cannot say I have definitely seen both birds as my images seem to indicate I have only seen the same bird on many occasions. I think first-winter Glaucous Gulls like this individual are smart birds and always superbly marked.

(Glaucous Gull - © John Bridges)

A smartly marked bird, size can vary but most approach the size of Great Black-backed Gulls and some may even be larger (or appear to be). The fairly short primary projection is evident and obvious on this perched bird, coupled with the large bill and size this bird should cause little problem for anyone in the field. 

(Glaucous Gull - © John Bridges)

Nice almost translucent wing effect often evident from both above and below, often creates a sharp contrast between primaries/secondaries and rest of upperparts. 

(Glaucous Gull - © John Bridges)

A nice shot showing the creamy brown underparts, bicoloured bill, and fairly densely barred undertail covets. 

Ring-billed Gull - Irregularly seen plumages

1st-year bird, Kenniskis, Canada, 15 August 2010. For a first-winter bird, this individual is relatively unmarked. Given the time of year, it seems likely to be in moult, which would explain the lack of markings. Olsen and Larsson state that moult from juvenile to first-winter plumage takes place from July-September, and from first to second-winter plumage from May (in some extreme cases March)- October.On average, a 1-2nd winter moulting bird would have completed all but it's primary moult by mid-August when this was taken. Without seeing the wings very well in this photo this can be quite difficult to determine, but from what can be seen of the lesser and median coverts they appear to be in first-winter, not second-winter plumage, which would support the idea of a bird undertaking it's first moult. the crescent marks on the sides of the breast are a good sign of a first-winter bird and aren't normally shown on a first-summer/second-winter. Therefore I believe this bird to be a juvenile moulting into first-winter.

An easier bird to age, taken at Niagara, Canada, 31 August 2010. The Mantle has the dirty brown markings of a first-winter bird, and in most respects this bird has 'classic' first winter plumage, the head streaking is lighter than you would get on a juvenile, and it doesn't have the scaly mantle and scapulars you would expect on a juvenile bird. Therefore, personally I would age this as a bird that has almost entirely completed it's moult from juvenile to first-winter plumage, which fits well with the time it was taken. 

Identifying first-winter Ring-billed Gull in UK context

Identifying a first-year Ring-billed Gull in the UK is tricky, but do-able with good views. Despite typically having some brown in the mantle feathers, you can still see (as on the above bird) the paler grey mantle colour than a Common Gull. the grey crescents on the breast-sides and flanks are also a good indicator. In all plumages, Ring-billed is generally larger and bulkier than Common Gull, with a thicker, parallel-edged bill. It's head shape is typically squarer than Common Gull with a distinct peak behind the eye. They are also longer-winged, and have the jizz of a larger gull. Confusion can in fact be caused by second-winter Herring Gulls, but a direct comparison with larus argentatus should show a smaller, longer-winged bird, with a dark eye and more plaintive expression.

It is worth noting that the features of structure are often most obvious on a male first-winter Ring-billed Gull, many females can appear extremely similar to Common Gull, being around the same size, with a rounded head and more delicate expression compared to males. Given the number of adult Ring-billed found compared to the number of first/second winters, many, especially females, are doubtless overlooked for their similarity to Common Gull.

All photos are the copyright of Liam Curson, seek permission before any use, my e-mail can be found on the blogger profile to your left; thank you. 

Glaucous Gull (larus hyperboreus) - Hartlepool Headland - February 2012

The following photos taken over 2 Saturdays in early-mid February, they show a 1st winter Glaucous Gull (larus hyperboreus)

 (Glaucous Gull - 1st winter - © Andrew Kinghorn)

 (Glaucous Gull - 1st winter - © Andrew Kinghorn)

 (Glaucous Gull - 1st winter - © Andrew Kinghorn)

(Glaucous Gull - 1st winter - © Andrew Kinghorn)