Was it a Caspian afterall?

Well this is a tad embarrassing and unsatisfactory and also a good example of why I usually let others do the gull finding. Wasn’t it nice when we just had Herring Gulls? I’ve just had a nostalgic look at Peter Grants Gull book - the authorative text in the 1980’s - and cachinnans was just a subspecies which warranted 9 lines of text whereas now it warrants pages and pages and huge ID articles).

The gull which I featured in yesterdays post after the Glaucous Gulls was clearly strange enough to get my attention and document it and although it was Caspian Gull that was going through my mind the bird didn't match my own mental picture of what a 1^st winter Caspian should look like – an image formed by pictures of “classic” birds on the web plus this well watched 1^st winter from 2 winters ago (Caspian Gulls are still rare bird in Norway with few oppurtunities to study them around Oslo). When I got home I therefore was more interested in deciding whether the second Glaucous was a hybrid or not and didn’t spend too much time on the Caspo like creature. When I eventually did look at it my interest was again aroused although I was thinking more along the lines of a hybrid and I sent some pictures to Sindre M who agreed that it could be (probably was) a hybrid and I may have left it that but felt it was interesting enough to put it out on the Facebook group Western Palearctic Gulls asking whether there were others who thought it contained Capsian genes. The answers didn’t take long to arrive (despite the late hour) and there were immediate comments that it was a pure Caspian. This was a surprise as I had half expected comments along the lines of strange Herring Gull but the general consensus (with the excpetion of half of the Norwegian and Finnish commentators who prefer hybrid) was that it was a Caspian and Lou Bertalan even went to the trouble of scoring it on the Gibbons et al scoring system from a British Birds Article and placed it right on the Caspian side of the Caspian/hybrid threshold. Now I will be honest and not claim to fully understand how he has scored the bird (requires more experience of this field than I can claim to have) but based on this feedback then it would seem that the bird may be good! In an out of range context it might not be the classic looking bird we would want to find in Norway but equally it isn’t a Herring either and all these LWHG have enormous variation in plumage and structure such that where the lines are drawn are sometimes quite arbitrary and DNA apparently doesn’t always help either…..

I have posted the pictures on the Norwegian reporting system asking for comments but do not expect to receive any. The Norwegian birding community which is always shy/apathetic/worried about reputation (delete based on personal opinion) is currently going through a cyclical low in engagement  and I think at the moment you could post a picture of a Peacock labelled as a Blue Tit and nobody (OK there are a couple of people who care) would be arsed to comment.

So we will see where this gull ends up. At the end of the day it will be my fellow NSKF members who will be responsible for making judgement on the bird (unless the species gets removed as a national rarity before then.…)

Here are my pictures of the bird (yesterday’s plus a couple more) plus the scoring done by Lou Bertalan on FB based on the first 2 pictures.

And Lou Bertalan's scoring (from Facebook):

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Extent of scapular moult
1 a small number (less than 1/3) of first-generation feathers remaining

Greater-covert pattern
1 white edges with delicate notches or vermiculation; or dark brown centre with white tip to 1/3 of length (i.e. white restricted to tip or distal third)

Bill shape
1 Slim, slight gonydeal angle (ratio 2.87, so actually >2,8 but there is a slight gonys angle visible)

Leg length
1 Moderately long

Ventral bulge
0,5 - there is a very slight bulge visible but note especially the flat belly in front of it!

Primary projection
1 moderately long (ratio 0.5

Moult: greater coverts
5 no moult

Moult: median coverts
4 one or two feathers moulted

Moult: tertials
3 all old

Darkness of head and body
1 reduced grey wash or streaking (confined to flanks and/or single streaks around nape)

First-generation tertial pattern
1 fine pale fringe around distal portion (like classic michahellis), possibly also with some vermiculations

Second-generation scapular pattern
2 strong, contrasting shaft-streaks, anchors and/or dark central diamonds, but these more patterned feathers are less than 1/2 of all; ground colour creamy or silvery-grey, possibly with some grey feathers mixed in.

so this makes a score of 21,5 which is still within cachinnans, close to the border to hybrids. but it also illustrates some weakness of this scoring system. covert moult weighs too much, imo (5 points for no replaced GC!), there is no criteria for rectrices pattern which personally i give a lot of weight, and it simplifies matters of 2nd gen. scpaular pattern: there are certain types of scapular patterns and each one should be scritinized separately.

what i'd still discuss in this bird is: head jizz (mentioned as not good for caspian gulls) - yes, could sit on a weak female YLG too, especially with the slight eye smudge, but caspians can show even more dark striation around eye than this. scapular pattern is of the shaggy type with one central transversal mark and only a weak thin (or absent) subterminal band. this is a common type in caspian, can appear in other taxons too but usually more bold (double anchor in YLG, bold subterminal bar giving a scaly look in HG), which i think is often underestimated because one likes to have the nice diamond shapes or just shaft streaks as typical cachinnans pattern - but this distorts reality since at least half of all 1st winter caspians don't show this kind of expected pattern but the one more similar with the other taxons. tail in this bird is very good for cachinnans, inner wings shows the nice venetian blind with p2-4 showing pale lozenges etc...

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With regards the score of 21.5 (which is a bit cheeky as I don't think the system was meant to allow half points) the range for Caspian is 12-25 and the range for hybrid 22-32 so as you see right on the (edge of) the border.

Today I went birding at Fornebu. I didn’t find any pipits (had been talk of something possibly rare there yesterday) but the reedbed at Koksa was positively hopping with birds. A flock of Long-tailed Tits were feeding in the reeds along with good numbers of Blue Tits, Great Tits, Wrens, a Robin and surprisingly 5 Goldcrests. Best of all though was hearing at least a couple of Bearded Tits which wouldn’t show themselves but at least dispels my previous conclusion that they had moved on/perished.

A Long-tail where there should have been a Beard

Caspo

I’ve settled into a daily rhythm which strangely enough revolves around gulls. Today I also succeeded in seeing an interesting one with the Caspian Gull turning up at Langvannet again after it has become less predictable the last week. It was sitting waiting for bread when I arrived at 0935 and showed well during a couple of spells when the gulls sat on the ice but twice they were scared by Goshawks and then took quite a while before they returned. I had two adult male Goshawks together at one stage (one chasing the other) and last week there was a 2cy there so this is clearly a popular take-away for this raptor.

I managed to quite easily pick out the Caspian Gull in flight which raises the possibility of IDing one on a seawatch in the future.

Moving back into Oslo I failed to find any interesting gulls which I had hoped the recent storm “Nina” may have pushed up into the inner Oslofjord. Water had been pushed in though and the sea was a good 2 metres higher than normal. The Botanical Gardens were also devoid of interest with a single Hawfinch and a singing Goldfinch the highlights (the fact it was singing rather than the species).

First a video of the Caspian Gull where it calls a couple of times. Some say they can pick out this species just on call. I lack the experience to do that. Here it is giving a short call rather than the “long call” when they throw there head back but I definitely wouldn’t be able to pick one out just on this call.

1st winter (2cy) Caspian Gull

2nd winter (3cy) Herring Gull left and 1st winter (2cy) Caspian right. 1st winter Caspian Gulls differ from Herring Gulls of the same age in that they have already moulted a number of grey mantle feathers which can be seen on the back. A potential trap for the unwary though is a 2nd winter Herring Gull though as can be seen here which has also moulted a lot of grey mantle feathers and can be quite white on the head. Note the rounded tips to the feathers of the Herring Gull which is typical of older birds which have moulted their juvenile primaries but that the same feathers are pointed in the younger bird as they are still the juvenile primaries.

lots of contrast in flight

and even more from above

 

the Caspo coming into land

the two adult male Goshawks

some colour in Botanisk Hagen. Tree Sparrow (pilfink) and Greenfinch (grønnfink)

Breaking my rules

News leaked out yesterday evening of a Caspian Gull (kaspimåke) seen in Fredrikstad first on Sunday and then again yesterday. I wasn’t sure as to whether to go for it today given that 1.) it would mean twitching, 2.) an hour and a half drive, 3.) it was a gull and 4.) it was dangerously close to The Great Big Dump, Øra. I awoke in a particularly positive frame of mind though and thought what the heck. After getting the girls off to school and kindergarten I headed south. I was not happy about the heavy rain which as usual didn’t correspond with what the weather forecast from yr.no was telling me it should be but as I approached Fredrikstad it dried up.

The bird had been seen in Gamlebyen which is the old fortified town at Fredrikstad (one of precious few such historical fortresses in Norway) and as I made my way through the cobbled streets and parked by the river I saw there was another birder present. It was, as I suspected, Eirik Grønningsæter who is attempting to break the Norwegian year list record and had left Trondheim at 2am to get here (see his Big Year blog on my blog list). We stood there, threw out bread, scanned the gulls, chatted with a couple of other birders who popped in (including finder Asgeir Larsen), stood there some more, scanned some more, chatted some more, threw some more bread and three hours passed so quickly (not!). There were around 100 Herring Gulls in the area but there was little movement (there were most likely another 1000 just down river at the Great Big Dump). It is amazing how little gulls do during the course of the day and they were also not so interested in the bread we threw out to them (although the bread old ladies had to offer was scoffed up) and it is a wonder they get enough food. As you guess though the bird in question didn’t turn up (although it is still in the areas a unfortunately late report came in after dark that it had been seen at the Great Big Dump).

If you pay enough attention to large gulls you always find some odd ones and there were a couple that stood out today. Norway has a handful of experienced and knowledgeable larophobes and they are split into two “schools” (or they are by me at least): the Eastern (ES) and Western Schools (WS). From what I can see they differ in their teachings (and both schools have their disciples) by how they deal with non classic specimens. For the ES it would appear that anything odd that can’t be placed with safety in a bucket gets called a “presumed Herring Gull” with Herring Gull being the default as it is the commonest large gull in Norway. The WS however seems to prefer to use other labels for atypical birds and one particular type of bird causes a lot of debate namely the “Bergenshybrid” which to the ES is a pale extreme of Herring Gull whereas to the WS are hybrids (though not necessarily 1^st generation) between Herring and Glaucous Gulls. I have spoken (tediously and at length) about these birds before and today there was a nice example of such a bird (pictured below). Personally I’m not really sure how to classify these birds but tend towards them being “just” pale Herring Gulls because they seem to be so regular in the south whereas Glaucous remain a real rarity such that I can't understand where all these birds would originate if they were really hybrids.

On the other hand there are a number of other birds that the ES label as “presumed Herring” which show great similarity to Caspian and Yellow-legged Gulls and for which I believe it is wrong to not try to put another label on as they push the boundaries of what a Herring Gull looks like and is I think far too simplistic (to put in at another way there is no way these birds would be accepted as vagrant Herring Gulls in Southern Europe). We had one such gull today (pictured below) which for me had a lot of Caspian features although was far from ticking all the boxes. However, it was also outside what I would expect a Herring Gull to look like  – it could well be a hybrid which seem to be fairly regular in many mixed colonies in Poland and neighbouring countries. This particular bird bore a colour ring allowing part of its life history to be found at the few clicks of a mouse. This bird was ringed in Oslo on 4^th September 2012 as a Herring Gull in its 2^nd cy (i.e was over a year old). On 4^th November it was 261 km away in Hirtshals in Denmark before returning north on 23^rd November to Moss (only 50km from Oslo) when it had the misfortune to be trapped again. It was then seen in Fredrikstad on 31.12.2013 before my sighting today.

When you stand in the same place for three hours you see or hear a few other birds and we heard a migrating Skylark (sanglerke) which is my earliest Norwegian spring bird by a long way. On my drive home I had three roadside Great Grey Shrikes which is back to the expected level after a couple of quiet months and could also well be a result of spring migration having already started for this species. A well timed stop to expel excess liquid also revealed calling Bearded Tits at Sorgenfrigropa.

Extreme, pale Herring Gull aka "Bergenshybrid", alternatively Herring x Glaucous Gull Hybrid (2cy)

note the pale wing with the outer primaries being the same brown colour as the darkest feathers elsewhere on the wing.

Here are three birds of the same age (2 cy) with the rear two being normal Herring Gulls. Note how on the paler bird the white edges to all the wing feathers are much broader creating a much paler impression

the pale bird is on the left. In addition note the broad pale edges to the primaries

 Unidentified large gull with possible Caspian Gull genes (3cy)

 

the colour ring "JU2E" has allowed me to see some of this gulls life history and it was ringed as a Herring Gull with no special note made by the ringers.  Note the white head, breast and underparts and grey "shawl". This bird had a distinctive jizz with long wings held low as well as a drooping tail

here with 5 Herring Gulls note the difference in jizz with droping tail and wings plus the different head shape.

a Caspian Gull should show dark greater coverts and tertials whereas this bird has peculiarly pale ones

the tail band is not dark enough and without a clear cut boundary to a white rump

Also two birds that I do consider to be within the range for Herring Gull although both stood out.

Yellow(ish) legged adult Herring Gull

this birds legs had a yellowish tinge.  Note also the almost orange bill which stood out compared to all the other adult Herring Gulls.

The primary pattern doesn't suit a real Yellow-legged Gull and it also had an orange rather than red eye ring so this bird is most likely just within the range of Herring Gull

 Green legged adult Herring Gull

this bird stood out with a slightly long winged and upright jizz and the green legs are more appropriate for Caspian than Herring Gull but there was nothing else particularly unusual about this bird (although I never saw it in flight)

Back in business

The festive season is well and truly over, the diet and healthy living has begun, the kids are back at school and the birding games can recommence.

I started by paying a visit to the Caspian Gull (kaspimåke). When I arrived on site I soon realised that I had not dressed for the occasion and after noting that it was not among the 50 or so Herring Gulls (gråmåke)sitting on the ice I retired to the slightly warmer car and kept my eye on any new gulls arriving. It took a while for anything interesting to turn up but after 45 minutes a large, pale gull flew in. It wasn’t the 1^st winter Glaucous (polarmåke) that I had originally hoped for but was in fact a very good candidate for a genuine Glaucous x Herring hybrid rather than one of the lookalike pale Herring Gulls that hatch in the Oslo Fjord. It was also ringed with a metal ring and the ring said Moscow! I didn’t manage to read off the whole number but Sindre M. managed to later so it will be interesting to see what info comes back about this bird.

While watching this bird a startling black and white tail band flew into view and the Caspian had arrived. In flight it was incredibly obvious as it also was on the deck and when birds are in this plumage then they are relatively straightforward. The Caspo initially sat at the back of the gulls but eventually came much closer. Just as I settled down though to take some photos a young Goshawk (hønsehauk) sent all the gulls up in the air and during the course of the next hour none returned to the lake.

With me losing feeling in my toes I needed to get the car warm so drove into Oslo. The Botanical Gardens failed again to give my any 2BCs but I had a great encounter with the resident Long-tailed Tit (stjertmeis) flock drinking and bathing in a couple of areas of open water on an otherwise frozen stream. Here a video of the usual handheld quality but it isn't often one gets to video this species.

 

 

Heading to the area around the Oslo I was “excited” to see hundreds of gulls and set about grilling them with what some anticipation. I soon found a pale gull which on closer vies showed itself to be exactly the same ringed Glaucous hybrid from earlier which I had last seen 1hr 55 minutes previously 12.5km away. This area is clearly a major loafing area for all the gulls in the Oslo area so checking here in the evenings before the birds go off to roost on the fjord should also produce the Caspo.

The 1st winter (2cy) Caspian Gull

Caspian Gull in the background and Glaucous X Herring Gull bottom left

Here the large size of the assumed hybrid can be appreciated

this picture and the previous two were taken at Langvannet in Lørenskog

an hour and 55 minutes later it was on the ice by the Opera in Oslo 12.5km away

a close up of the ring with the MOS of "MOSKVA" visible

a bit more of the ring is visible. It looks as though the individual code has been engraved by hand!

the Long-tailed Tits

this Crested Tit (toppmeis) in Maridalen allowed close approach

also this bird is ringed but most likely exactly where I saw it

Pallas’s Gull - All hail Sindre Molværsmyr!

This evening I have been a bad person for so many reasons but you know what, I like it! It probably helped that I had already started mentally preparing myself for looking for gulls tomorrow and was getting in the right (or wrong depending on how you look at it) mental zone that I found myself abandoning the kids (although did first feed them and help with homework) to race down to the docks in Oslo to twitch a gull. And not just one gull but two! Quite amazingly the multiple Caspian Gulls had been joined by a Pallas’s Gull (steppemåke). This bird should not have been here at all. Not at this time of the year and most definitely not in this urban setting. This first for Norway breeds on lakes in steppes east of the Black Sea, winters in the Persian Gulf and is as a result exceptionally rare in NW Europe.

I got the message on the bird via the Bird Alarm app at 1651 with the headline New Species (meaning new for Norway and therefore not available in the predefined list of species in the app), Oslo, Sindre Molværsmyr. Clicking on the message I saw it was a Steppemåke at the insalubrious location of Vaterland. I had to get out the bird book to find out what this was in English ;-) and was shocked to see it was a Pallas’s Gull or the bird formally known as Great Black-headed Gull. Being in the middle of making dinner, with homework to do and Mrs Oslobirder working late I tried not to think too much of this bird that was only 10 minutes drive away and secretly hoped it was a misid (I was thinking of a large Caspian Gull...) A phone call at 1827 (thank you Jarl!) which went along the lines of why aren’t you here it’s showing really well now at the mouth of the river by the Opera and me asking it is “good” and getting the answer yes very good had me asking the girls whether they wanted to go twitching. The not unexpected and resounding answer of no was then followed by a but we don’t mind being alone was all I needed and less than 15 minutes later I was watching the bird alongside about 20 others at point blank range and right by the car and in a nice location!!. Seeing the bird I felt bad for ever having entertained the idea it could be a misid – it was a magnificent beast! Sindre who found this bird plus different Caspian Gulls each of the last three days is to be truly applauded for an amazing find. There are a few people in Norway who have a reputation for working hard and finding rare gulls but I don’t think anyone has ever come close to this run of finds in such a short space time.

I also got to see one of the Caspian Gulls but only briefly in someone else’s telescope and when I then tried to refind it to enjoy it (after having concentrated on the Pallas’s) it was no longer to be seen. With the thought of the kids burning down the house in the back of my mind now moving to the front of my mind I had to head home and was back within the hour that I had promised. I am now, in a very unexpected and slightly uncomfortable way, looking forward to searching for gulls tomorrow!

despite their best efforts the muggers had not yet succeeded!

look at that white underwing

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it readily joined in the fray when bread was on offer

 A short video