Sunday, December 20, 2009

Possible European Herring Gull

There has been a very informative discussion of late on European/Vega Herring Gulls on ID Frontiers so I was a bit stunned when I spotted this bird literally at my feet today at the SSM Landfill. It immediately stood out to me as the best (and only) candidate for a European Herring Gull - Larus argentatus argentatus I had ever seen. After reviewing every available reference and picture in print and on the net I am still thinking that this seems to meet all the criteria for European Herring Gull.

For those not obsessed with Larus taxonomy. The three Herring Gulls- European, Vega and American are still even after a recent review considered subspecies of  Larus argentatus - argentatus, vegae, smithsonianus respectively by the AOU. The BOU and virtually everyone else including Olsen & Larrson consider them distinct species. Seperation European and American Herring Gulls can be most difficult but in some cases may be possible especially in first year birds.

So here is my candidate for Larus a. argentatus



Possible First Winter European Herring Gull


 So clearly this is a first winter bird and has molted its juvenile mantle and scapular feathers. First notice how pale this bird is overall with a white ground color and a frosty appearance. The coverts are spotted and the tertials heavily notched.







Possible First Winter European Herring Gull-Close Up


The mantle and scapulars are pale and lightly barred. The notching of the tertials is well demonstrated
The coverts and mantle in this bird appear to be nearly identical to the L.a argetatus illustarted in Olsen & Larsson pg. 269 #331. Lets move on to the tailband.









Possible First Winter European Herring Gull -Tail Band

This bird has a broad blackish tailband with barred bases of the outer tail feathers with white tips. The upper tail coverts have a white ground cover. This is probably one of the best features for distinguishing between American and European Herring Gull. Below are several pictures showing the typical American Herring Gull tail. All black with heavily marked rump and coverts.















First Winter American Herring Gulls- Tail Pattern

Here are a few more pictures showing the sparsley barred undertail coverts and a comparison with a typical American Herring Gull.

Comment: Tony Leukering noted " I was curious as to the photo date of the second picture of smithsonianus depicting typical tail patterns.  It's bill pattern suggests a bird older than a 1st-cycle, though the primaries might be pointed enough to be juvenal feathers.  The mantle also seems to show some older-type feathers, but I cannot be sure from the picture."


The picture was from Nov. 9th/2007. Looking at the whitish rump and bicolor bill plus the mantle I think this is likely a second cycle bird. Thats what you get for doing the blog at 0300.
Kirk


Possible First Winter European Herring Gull- Undertail Covert




Juvenile American Herring Gull - Undertail Coverts

On to the wings. The European Herring Gull is supposed to differ from the American in the absence of dark tips on the inner webs of the inner primaries (P1-3)with two-toned outer primaries.









Possible First Winter European Herring Gull - Wing with Close Up

Well P 1-2 are certainly devoid of dark markings on the inner web tips and P3 has some pale gray markings. Here is an American Herring Gulls for comparison.





First winter American Herring Gull - Wing Close Up

Here the tips of the inner webs of the inner primaries clearly are darkly pigmented and the pattern noticeably different from the candidate European Herring Gull.

Below are a few more pictures the first showing showing the underwing.







Possible First Winter European Herring Gull

The only thing I could find weighing against this being a European Herring Gull was a comment in Howell and Dunn that this taxa does not typically show a flesh pink bill with a clean-cut black tip which my candidate bird does. Olsen & Larsson don't specifically mention this point. In the superb article by Lonergan & Mullarney entitled Identification of American Herring Gull in a western European context they state:

"Bill-colour There is a tendency for both smithsonianus and argentatus to develop a pale bill base quite early in the first winter, with the most extreme birds approaching first-year Glaucous Gull in this respect. In argenteus the contrast in the bill pattern tends to be subdued until late winter".




 This article is available on the net at the following link:


http://www.irbc.ie/notes/pdf/IdentificationOfAmericanHerring(Mullarney&Lonergan).pdf


It would seem according to this expert opinion that the bicolor bill is not an issue for L. a. argentatus.


In conclusion I feel this bird is a very good candidate for a first winter European Herring Gull. I have spent 100s of hours over the last several years studying 1000s of first winter American Herring Gulls and though the variation is truely remarkable I think this bird may well be out of range.


I would very much appreciate any opinions especially from those with experience with this difficult diagnosis.


Kirk





Sunday, December 6, 2009

Psuedo Nelson's Gull and others

Well we finally got some snow. This makes for much better photographic opportunities at the landfill as much of the garbage gets buried. It also makes for much better manoeuvring when the ground freezes as your not walking in deep muck. All in all its a better place when things are frozen.




Juvenile Glaucous Gull


Given the relatively warm weather most of the 4-5 thousand Herring Gulls are still around with probably 1500 plus at the Landfill yesterday morning. Noticeable changes have occurred over the last couple weeks.
First although I thought this was happening it was clear this year that the juvenile Thayer's Gull leave in late November. It has been two weeks since I have seen one and there were at least 4-6 around. Right on schedule the first adult Thayer's Gull of the season turned up last weekend. Skye Haas was telling me they find adults in the Marquette area (200 miles west on south shore of Lake Superior) consistently in late October but I virtually never see them here until late November. It was present again this weekend and given a bit of black flecking on the tail and wing coverts must be a 4th winter bird.







4th Winter Thayer's Gull

This bird certainly meets the criteria for Thayer's Gull but really has a petite structure with very rounded Kumlien's-like head.  The dark eye, strong hood, greenish yellow bill base and of course reduced white on the primaries with dark markings on P5 to P10 all fit with Thayer's.  I spied what I assumed was the same bird later but when it flew I noted it didn't have the tiny dark flecks on the tail. It returned and was cooperative for pictures. I noted that it looked very petite as well probably well within the range of Kumlien's. On examining the photos this bird only had dark markings on P6 to 10. P5 was pristine white tipped.






Adult Thayer's-Kumlien,s Gull "Intergrade"

Bruce Mactavish and Steve Howe did a study looking at dark markings on the primaries and I believe this bird would fall at the very extreme end of the Kumlien's cline and given the dark heavy hood I would call this an "intergrade" for lack of a better term. I am reluctant to use the word hybrid as that implies that Thayer's and Kumlien's are distinct species which is certainly not the case. If you believe Thayer's and Iceland Gull are distinct species and Kumlien's are a hybrid swarm then this bird is just part of that swarm. If you believe Thayer's, Kumlien's and Iceland are all part of a single variable species than this bird is just part of the cline. I prefer that former theory and see it as analogous to the Western, Olympic, Glaucous-winged Gull situation that is unfolding before our eyes.



Adult Thayer's-Kumlien's Gull "Intergrade" - "Head Close-up"



Adult Thayer's-Kumlien's Gull "Intergrade" - "Primaries Close-up"

The close-up of the head shows the "in between" eye colour and the heavy hood which would be  unusual in most Kumlien's. This is a neat bird as it is very just one small step towards Kumlien's and very closely resembles the adult Thayer's Gull present.

Well while contemplating this a large very white headed gull with a bright yellow bill and reduced black on the primaries flew by. I followed it in my binoculars thinking that this must be an adult Nelson's Gull.
It eventually returned and I could see it was a largish Herring Gull size with very little head streaking and a bright yellow bill and brighter than usual pink legs. All seemingly Glaucous Gull features.





Adult Glaucous Gull

The above picture illustartes the bright yellow-orangish bill, the lightly marked head and the deep pink-red legs typical of a winter adult Glaucous Gull.  I managed to eventually get real good looks at the "Nelson's" Gull and I noted that something was not right with its primaries.






"Pseudo Nelson's" Gull- Adult Herring Gull in Delayed Molt

Well on examining the pictures it all became clear. It appeared that P9-10 were very old and worn and P8 was only half in and the rest were fresh and full grown. Since P8 was still not grown in all the grey on the old worn P9 was visible and all this added up to a lot less black. The lack of head streaking, the bright yellow bill and the pinker than average legs could all be explained as part of a delayed molt in this adult Herring Gull (I think anyways). I am glad the bird came back because on my first look on the flyby I was quite convinced it was a Nelson's Gull.

The biggest change in the gull population since the cold weather hit is a big increase in Glaucous Gull numbers. All age classes were present with at least 15-20 juveniles. Kumlien's Gull also increased significantly with about 8-10 juveniles and 3 second cycle birds. The juvenile Lesser Black-backed made an appearance and for the first time this season I struck out on Ringed-bills.



Juvenile Kumlien's Gull


Second Winter Kumlien's Gull



The snow allowed for some semi-artistic flight shots. After about 3 hours I had majorly frozen hands and feet and my face was so cold I couldn't talk (not that I usually talk much at the landfill by myself - just to clarify as most people think your crazy hanging out at the ladfill to begin with) so I headed home. I am going to miss my usual Saturday morning session next week as I am heading for Texas to look for Hook-billed Kites at Santa Anna. The next week I will spend all of Saturday at the Landfill as part of the Sault Ste. Marie CBC.





Adult Glaucous Gull




Third Winter Glaucous Gull





Adult Thayer's -Kumlien's Gull "Intergrade"





Juvenile Great Black-backed Gull

Thanks for checking out my blog and I am keenly waiting for your insightful comments.

Kirk

Sunday, November 22, 2009

Nelson's Gull

Nelson's Gull was originally described as a new species by H.W. Henshaw in The Auk Vol. 001 No.03 in July of 1884.  the original article can be accessed at  http://elibrary.unm.edu/sora/Auk/v001n03/p0250-p0252.pdf .


It was named after Mr E. W. Nelson an Alaskan ornithologist who had collected the first specimen of this distinct taxa. Henshaw compared its similarity to Glaucous Gull as Kumlien's is to Iceland Gull. He also noted its resemblance to Herring Gull. Although initially described as a distinct species currently it is well accepted that Nelson's Gull is a hybrid of Glaucous and Herring Gull.



Juvenile Nelson's Gull in flight

It would be safe to say that traditionally Nelson's Gull is the most common hybrid gull on the Great Lakes and eastern seaboard. Lesser Black-backed X Herring Gulls and Great Black-backed X Herring Gulls are becoming increasingly common and may rival Nelson's at some locations. Nelson's Gull is of course also seen in the west being described from Alaska and recorded along the west coast into Southern California. In many areas of the west it is vastly outnumbered by the "Olympic Gull" the hybrid result of Western and Glaucous-winged Gull "interaction". In the Anchorage area it can be hard to find any pure large gulls the majority being Glaucous-winged X Herring hybrids. Fortunately in the east hybrids are still an oddity and vastly outnumbered by pure birds.



Adult Herring X Glaucous-winged Gull





Adult Herring X Glaucous-winged Gull

The two Herring X Glaucous-winged Gull hybrids above were photographed at the Palmer Landfill north of Anchorage. The first bird looks like a stalky Herring Gull. The white eye and orange orbital ring is typical for Herring Gull. The primaries are an odd greyish-black. The second bird has a dark eye and pinkish orbital ring typical of Glaucous-winged Gull and the same odd greyish-black primary coloration.

On the shores of eastern Lake Superior Nelson's Gull is still a relatively rare find. The first record that I am aware of was a juvenile photographed at the Sault Ste. Marie landfill in November of 2005. It stuck around for two months and was a regular feature at the landfill. I  imaginatively nicknamed him "Nelson".



"Nelson" the Nelson's Gull

Since the  initial sighting I have seen about one Nelson's Gull per season. A noted exception to this being this year with a minimium of three birds being present. All the birds except one have been juvenile birds. I have never seen a third year bird or an adult locally. My initial impressions were that juvenile Nelson's Gulls looked distinctly like a Glaucous Gull with some dark pigment on the primaries as was the case in "Nelson".






"Juvenile" Nelson's Gull - St. John's

The "Nelson's Gull" pictured above photographed at the St. John's Landfill looks to be identical in size and structure to the pure Glaucous Gulls. The only difference in plumage that I can discern is the dark pigmentation of the primaries. A second winter bird I photographed subsequently in the Soo further suggested to me that the Nelson's Gull was dominated by Glaucous genes.











Second winter Nelson's Gull showing faint pigmentation and "ghost' primary pattern on both wings

In the first picture above I think one can discern some structural differences from the average Glaucous Gull especially in the head shape. The bill however is entirely Glaucous Gull. Unlike the above pictured juvenile bird I think this bird does have some subtle plumage differences from Glaucous gull other than the faint primary pattern.






Second- winter Glaucous Gulls

The second winter Glaucous Gull usually has some dark smudging scattered about and a white ground color but little or no fine barring. The coverts are largely unmarked with just a bit of dark smudging. The second winter Nelson's Gull shows dark smudging along the neck but has some fine vermiculations on the scapulars and wing coverts and tertials which I believe would be out of range for Glaucous Gull. In this view I also note some gonydeal expansion of the bill that also suggests Herring Gull influence.                                                                                                                          




Second Winter Nelson's Gull

This year I have seen three juvenile Nelson's Gulls. One was very similar to the previously noted birds - basically a Glaucous Gull with darker primaries. The other two however were much further towards the  Herring Gull end of the spectrum than any I had viewed previously.











Juvenile Nelson's Gull

The above bird although certainly very Glaucous Gull - like shows a lot of Herring Gull influence in the plumage especially in the juvenal scapulars and tertials. The primaries show relatively heavy dark pigmentation somewhat reminiscent of Thayer's Gull. The next bird is even further down the Herring Gull line to a point where I was intially unsure if in fact it was just a pale Herring Gull.







Juvenile Nelson's Gull (probable)

The structure of this bird screams Glaucous Gull (well maybe only shouts). The bill, head shape and general feel of the bird is Glaucous. In the closed wing view it has a lot of fine vermiculations on the scapulars, coverts and tertials belying Glaucous Gull influence. The primaries are perhaps just a shade paler than the Herring Gull but in the open -winged view I think there is definitely  decreased pigmentation of the flight feathers and the primary coverts which would have to be at the extreme end of the range for Herring Gull. I believe but am not 100% certain that the following picture represents the same individual. The eye is clearly white in this better light which is atypical in first year birds for both Herring and Glaucous Gull. It is certainly acting goofy which is very characteristic of Glaucous Gull but can certainly be an attribute of any of the larger gull species.



Juvenile Nelson"s Gull (probable)

Unfortunately this was the only close-up picture I managed before it flew the coop. After reviewing the Nelson's Gull pictures on-line and in the literature I have concluded that there is a very wide variation especially in the plumage of this hybrid. The overwhelming majority of these hybrids have Glaucous Gull type structure and bill.

Correction: Thanks to Kevin McLaughlin for pointing out that the above bird is not a juvenile but a 2nd year bird. Here are his helpful comments:


This is concerning the Nelson's Gull from the November 22 posting. This is the bird immediately above the Glaucous hybrid with the California Gull in San Diego. The bird is looking skyward out of its left eye. You label it as a juvenile and this is where I have a concern. There are several things which point towards a second basic bird. A few roadblocks are there as you allude to. This is the only good photo and as a result, only one side of the standing bird is shown. We have no assessment of the open wings, tail and so on. The bill pattern is good for a second basic Glaucous, Nelson's or Herring Gull. I have never seen Nelson's or Glaucous in juvenile or first basic which had a pink area at the tip of the lower mandible like this bird. They always show a bill with a complete black tip, the remainder being pink or bubblegum pink. The upperparts look too variegated, too messy, for a juvenile hybrid combo. The finely white spotted pattern on the greater coverts is absolutely bang on for a second basic Herring and by extrapolating this to a suspected hybrid, can fit that as well. The edge spotting gets larger on the inner greaters at the margin and this is normal for second basic. As you know, some juvenile-first basic Herrings and Thayer's, for example, can be finely marked on the greater coverts also but I do not believe that they will ever show the larger notches on the inner greaters as shown on a second basic. I intend on checking into this point however. To carry on, the tertials show several fine white spots on the outer margin and I consider this as being most likely, age diagnostic for second basic. (mind you, you can see this on third basics as well, so I mean to say diagnostic vis-a-vis first basic).The last point is the most obvious one and that is the colour of the eye. This bird shows a clear straw coloured eye, just right for a great many second basic large gulls, and absolutely wrong for a juvenile or first basic. I won't say that this aberrant eye colour could never happen in a first year bird, but can say that I have never seen it happen in the field or in photographs.





While in San Diego several years ago I photographed a hybrid gull that I initially felt was likely a Glaucous-winged X Glaucous hybrid (based on likelihood I suspect). On reviewing the pictures I don't think given the bicolor bill and the heavy wear and bleaching that you can be certain it's not a Nelson's.


Worn First Winter Glaucous Gull hybrid  Second Winter California Gull



Worn First Winter Glaucous Gull hybrid

I have yet to stumble across either a third winter or an adult Nelson's Gull locally. I have seen at least a couple adult Nelson's Gulls along the Niagara river but they were to distant for good photos. Brandon Holden has some great pictures of Nelson's Gull as well as other interesting hybrids on his web page of unusual Ontario Birds      http://www.peregrineprints.com/ind__UOB.htm     .

I will report later in the week on The First Annual Sault Area Gull Roundup that I coordinated (its not to difficult coordinating one participant especially if its yourself) last Monday.

Comments are always welcomed.
Kirk