Baltic Gull at DIRFT 3

The first confirmed record for Northamptonshire.

The construction site for the Phase 3 extension of the Daventry International Rail Freight Terminal (DIRFT 3) has become renowned for producing some interesting birds over the last 3 years. The area of flood pools alongside the A5 have, to date, attracted a variety of spring passage waders as well as gulls, which are known to commute between the site and nearby Shawell, where there is a landfill alongside other suitable habitat .

By this time of the year, most of the wintering gulls have departed, leaving a much smaller number of non-breeding immatures and a handful of adults, all of which are frequently joined by northbound migrants. It was on the morning of 16th May when, going through some 250 or so gulls at DIRFT 3, I came across a very interesting-looking, sub-adult Lesser Black-backed Gull, which stood out from the crowd by virtue of its startling black-and-white appearance, with almost jet-black upperparts and wings, which appeared virtually as black as the bird’s primary feathers. Closer examination revealed an extremely long primary projection beyond the tail, along with a relatively slim-looking body, lending an almost tern-like appearance.

Second-summer Baltic Gull, ring number J129K, DIRFT 3, 16th May 2021 (Mike Alibone)

Alarm bells started ringing as I realised I was almost certainly looking at a Baltic Gull, the (sub)species of Lesser Black-backed Gull with a breeding range from certain parts of Norway, Sweden and Finland to the White Sea.

The bird was resting on, and preening in, the water of the A5 pool and all parts of it were visible except for the legs. The bird was aged as a second-summer by some subtle dark brownish tones to some of the scapulars, faded blackish webs to 2 or 3 of the outer tail feathers, 2 small and inconspicuous pale brown feathers on the right side of the breast and a small, blackish subterminal mark on an otherwise adult-type bill. At all times during the observation the legs remained out of sight, below the water level.

Second-summer Baltic Gull, ring number J129K, DIRFT 3, 16th May 2021 (Mike Alibone)

I managed a few rather disappointing digiscoped shots and some rather ropey video before the gulls became disturbed by something unseen and took to the air. Although many returned, the gull in question headed off north with a handful of others, appearing to have very long, slim wings, and that, as they say, was that.

Having not seen the legs, it was not possible to ascertain if it was ringed or not … and reading the ring number to determine the bird’s origin and race is currently the only way to positively identify a Baltic Gull of this age in the UK.  

The potential similarity of the other European race of Lesser Black-backed Gull, intermedius, to Baltic Gull, fuscus, means that without ring detail, no UK records of the latter are acceptable to the British Birds Rarities Committee, the only exception being birds in their second calendar year between April and June (and perhaps into summer) through their unique moult strategy. Consequently, there have been only 12 acceptable records of Baltic Gull in the UK up to the end of 2019!

That would have been the end of it but for the fact that I returned to DIRFT 3 A5 Pools two days later … and there it was again – this time out of the water and as luck would have it, it was sporting a field-readable alphanumeric ring on its right tarsus, along with a small metal one on its left. The ring was of the same type used to ring intermedius and fuscus in Norway. I was half-way to getting an ID, one way or the other. Given that the potential interest level had just moved up a notch, I put the news out on the Northants Birds WhatsApp Group and contacted Carl Baggott, Leicestershire Bird Recorder and avid Laridophile with a first-hand experience in Baltic Gull, having recently co-authored a British Birds paper on their breeding at Horsvaer in Norway.

Second-summer Baltic Gull, ring number J129K, DIRFT 3, 16th May 2021 (Mike Alibone)
Second-summer Baltic Gull, ring number J129K, DIRFT 3, 16th May 2021 (Mike Alibone)

The problem was the ring was indecipherable as a result of a combination of heat haze and long range. I persevered and managed a few high magnification digiscoped shots of the ring, which were still very blurry. In the meantime Carl had arrived and had limited time to watch the gull, which had taken to sitting down and sleeping. In a short instance of the gull standing, Carl managed to read some of the ring number, the first two characters of which were ‘J1’. All good so far and then the gulls took flight and the presumed Baltic again flew north.

Later checking and attempting to sharpen my images revealed the last character of the ring as a ‘K’. With just two more characters to decipher I emailed them to Carl, who then shared them with Morten Helberg, gull ringing project leader in Norway. Both Morten and Carl agreed the ‘missing’ characters were ‘2’ and ‘9’. We had it! ‘J129K’, this number subsequently being confirmed in the field when Carl relocated the bird at Shawell later in the evening.

Ring Number J129K

So, with a bit of international cooperation and some ‘high level forensics’, we got there. But what about the bird’s ID? Oh yes, Baltic Gull, ringed as a pullus in Norway on 1st August 2019, as per the details below.

This is currently the only confirmed record for Northamptonshire. Along with the 12 records already accepted in the UK, BBRC is currently considering another half a dozen or so. As the committee quite rightly states, “… the British status of fuscus is being under-stated. In reality, fuscus may be of regular occurrence here.”  So, more will surely follow and a small number of likely candidates have previously been seen in Northants … but all remain unproven.

A big thank you to Carl Baggott (UK) and Morten Helberg (Norway) for their constructive input and swift information dissemination.

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