A Weekend for Caspian Gulls.

 

 

After a stark and beautiful 1st winter Caspian Gull yesterday, I headed down to the same site in an attempt to get better photos. I didn’t see the bird however a text from Dante Shepherd who had found a 1st winter Caspian at the O2 got me going. Unfortunately  I missed his bird but pics confirmed it was a different individual.

After 20 minutes or so this stunning 1st winter turned up in the middle of a bread frenzy.

 

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The bird flew off east and we decided to head to the Thames Barrier park again. Just after our arrival we encountered the bird below. To me it Looks very similar to the previous bird at the O2.

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Abit more bread throwing and this Rung (Yellow X090) 1st winter Caspian arrived on the scene, showed well in the dying light of an overcast late November afternoon.

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Rung as a chick through the same ringing project as the bird I had back in September by Ronald Klein in Redern East Germany.

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It has darker fainlty barred auxiliaries, and more heavily notched greater coverts than the first bird, although a good percentage of pure birds will show this. We had a couple of Caspians in flight which could well have been the birds present. But at least three today and a different bird yesterday shows they’re are about in good numbers!

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This faithful 1st winter Yellow Legged gull was one of only a few present during the day and is often present at Thames barrier park.

Abit about Wing Moult in first winter gulls

Hopefully readers will find this post useful. Understanding wing covert pattern and the advance of wing moult was a real turning point for me learning about gulls and a really important bit of information for identifying gulls in their first winter plumage.

Yellow Legged Gull numbers are continuing to drop here on the inner London Thames however a few 1st winters and an adult were lurking about on Sunday morning. Below are the 1cy birds showing wing, and in the case of the second bird, tertial moult.

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Wing moult, (shown above as the darker, diamond shaped, white fringed replaced feathers dotted amongst the first generation coverts in the wing) combined with other supporting features is a reliable method for separating 1st winter Yellow Legged and Caspian from Herring and Lesser Black backed Gulls. Supposedly caused by the former two species being born in a warmer climate with earlier breeding season and therefore an older bird by the time we see it here in autumn/winter.

Up until last month I had not heard of 1cy Herring or Lesser Black-backed gulls having replaced wing coverts before spring. The bird pictured below however , photographed in Regents Park London by Dante Shepherd this October, contradicts the rule and has included c40% of its wing coverts in its post juvenile moult.  These replaced feathers are less heavily marked than Yellow in Legged gull, with a pattern recalling 2nd generation Herring gull- type scapulars rather than the seemingly dark centered diamond headed coverts of YLG.

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Flight shot shows tail pattern and large window in the inner primaries, revealing the ID of this interesting bird.

N.B: It should also be said that if a bird doesn’t show any wing moult in its post juvenile plumage it could still be a Yellow-Legged or Caspian Gull, and this method should be used carefully in combination with other features.

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Today I received the ringing information for a 1cy Caspian Gull found on the foreshore at Thames Barrier Park on the 25th of September. 111 days and 970 km west of its birthplace.

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The bird was rung as a chick at Reddern Germany, near the Polish border on 06.06.16. Hatched into a 80% Caspian 20% Herring Gull colony.  A couple of heavily marked second generation scapulars as well as faintly notched first generation scaps could be an indicator of mixed ansestory at some point, however the replaced feathers are brand new, adding to the bold pattern and as far as i can see are within variation of the species. It’s worth pointing this out if the colony is known to be mixed and its impossible to say for sure. For more pics of this bird click here

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2 weeks in October on St Agnes, Isles of Scilly

Whilst the North East of the country was being showered in Siberian vagrants and rarities, the opposite end of the was slightly behind in avian terms. However a few great birds and many close encounters with species not so often seen by London patch watchers, plus very good company and pretty much constant clement weather made for a great trip.

A surprise find and a first for Scilly! was my personal highlight- this gleaming 1cy Caspian Gull dropped in front of me for a matter of seconds on the rising tide at Porth Killier/Browath, accidentally flushed by fellow house mate and Larid loather Lee Amery along with 30 or so Lesser Black backs towards Gugh, the latter species were present in notably higher numbers the day that the Caspian arrived. The bird wasnt seen again although number of Mary’s birders were high the following day.

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Due to occasional showers and an aching back, i didn’t always have my camera on me, but a few choice birds around the island were showy enough for a few shots now and then.

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Firecrests were seen and heard most days.

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Northern Wheatear

 

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A few Spotted Flycatchers were seen over the two weeks, including this 1st year bird that littered the ground under its perch with Red-Admiral wings.

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At times there were up to 6 Black-Redstarts on Periglis beach, with a couple of lone birds dotted about the island

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Tame old Scilly Blackbird

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Yellow-Browed Warblers were a daily occurence and seemed to fluctuate in numbers during the two week stay,  some days seeing 10+ on Agnes alone.

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There were two Red-Breasted Flycatchers in the Parsonage, a British tick for me! After a few near misses over the years.

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The Eastern Yellow Wag on st Mary’s (above) If accepted will be rarer still than Siberian Accentor in the UK…

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A tame Lapland Bunting was a half hour lying on my belly spent well.

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The last chance saloon!  this Red-Flanked Bluetail gave myself, Laurence Pitcher, Graham Gordon and Lee Amery (finder) a private show away from the crowds on our final day. Stoked for Lee for finding one of the last few BBRC Bluetails as it comes off the list this year apparently.

Just before the news of the Bluetail broke, the beginning of a long and widespread story began. Laurence Pitcher and I were handed a dead ‘Yellow-Browed Warbler’ by Islander Fran Hicks that had flown into his window at the lighthouse, the crazy story goes on from there and can be read in full here

A great two weeks away from the patch, although I hardly felt away from it with fellow Walthamstow enthusiast David Bradshaw being an October feature on st Agnes for many years.   Lovely people and lovely birds even the ones i missed out in this quick summary. But i’ll be spending more time year on this unique Island for years to come.

1cy Caspian Gull, Thames barrier park

 

 

A new spot along the river for me and good first visit. This German ringed 1cy Caspian Gull was hiding behind a cormorant for the first 20 mins after my arrival. Light conditions were very changeable and poor for photography at the best of times. I’ve not seen this age in September before so the developing scapular pattern is fairly unfamiliar to me, but through bins the bird had the 4 couloured appearance of; white head and underparts, grey tones appearing in the mantle, brown coverts and tertials and black primaries and bill. This stands out more in birds post October.

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The last two shots showing the pale underwing, broad un-tapering tail band and almost un-marked upper tail. Diffuse Wing bars made by the pale tips to greater and outer median coverts Also broader more patterned window than i’d expect on a Yellow Legged gull, of which there were a few individuals.

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I have contacted the Ringing project leader and will post the birds ‘story’ when i receive it.

2cy Gull, Thames o2 Greenwich

 

I originally had this bird down as a Caspian gull, this ID seemed the best fit on account of its very white underwing, the solid greater covert pattern and the ‘soft focus’ appearance of the replaced wing coverts and scapulars as opposed to the heavier marked and more contrasty remaining coverts of 2cy Yellow Legged Gulls at this time of year. It obviously also shows the features that are shared by both Yellow Leg and Caspian gulls of this age.

I’ve seen it since a couple of times and have had doubts as to whether it might just be a clean looking Yellow Legged Gull with a plain white axiliaries and white underwing.

The views I had originally were mostly from a position situated below the bird, fairly brief and in dying light.  Here are the problems ; The overall Jizz (the main thing thats bugging me), The iris is paling (which you can just see in a couple of the photos below and the last time I saw it the iris was even paler, almost bright.) Also no mirror on p10 (growing), not all Caspian Gulls at this age show it but it is apparently very rare in Yellow Leg, the bill is probably within range of Cachinanns but more suited to Michaellis. All this means its going down as a Yellow Leg, possibly with Cachi influence. Comments welcome

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