A 'probable' Caspian Gull at Whinney Hill Tip, Lancs, UK.

24.01.03. - Bill Aspin.

At the time of writing, I have no experience whatsoever of 'Cachinnans'.

However, this bird, even though distant, immediately grabbed my attention, due mainly to the jizz (mainly the head and bill) of the bird and also the upperpart colour. so I decided to take this 'grab' in fading, late afternoon light.

Unfortunately, details such as leg-length and certainly the primary pattern could not be made out due to a combination of being obscured/distant. The lack of this further crucial ID criteria means that the bird will never become anything more than a 'probable'. Neither did I see the bird in flight.

Once home, I decided that the bird was worth emailing for further opinion.

Below are the replies received from respected Gull enthusiasts:

Dick Newell; " This looks suspiciously like cachinnans to me.  However, the wings don’t extend quite far enough for me to say certainly that it is. Having said that, cachinnans wings don’t always look incredibly long. The head, bill shape, eye, what one can see of the bill colour all look spot on. Is that a long tibia that I can see? It looks a bit dark, but I would expect that in the evening light. I guess if this was submitted to me in Cambridge, UK, I would accept it as cachinnans – but we get lots of them (probably over 20 in the last few weeks). However, in a county where it is still a considerable rarity, I might say not proven."

Rudy Offereins; " Just looked at the picture and I'm not too sure this is a cachinnans but it goes a long way. The head is rounded/pear-shaped enough and although  I think the back is too dark compared with the Herring Gull next to it, the colour is of a neutral grey only reserved for Yellow-legged Gull and Caspian. Other features for cachinnans (legs, bill) are not realy visible in the picture. If this was submitted to me (only the picture), my judgment would be the same as Dick Newell."

Richard Patient; " this certainly looks interesting.
However in a county where it is very rare, this single image is not enough for acceptance in my view. If you can add some form of notes - certainly the exact pattern of p10 underside, then I would regard it as acceptable. If not, only 'probable'."

Chris Keyoh; " it's a bit difficult to make out much in the pic other than to say that the bird seems to fall into the argentatus/Caspian frame. Although several aspects of the jizz look promising for Caspian, I can't yet see enough to not ask why it isn't just an 'argentatus'. It's certainly worth looking for again. Differentiation of Caspian and some 'argentatus' (perhaps esp birds from the south east of the range) seems to have been an underestimated problem - features such as head pattern, bare parts (incl. leg colour) and primary pattern can be surprisingly similar and a small proportion of such birds seem to have dark eyes too!  Strange though it may seem an assessment of leg length is probably one of the most useful starting points. I guess someone who sees Caspian Gull regularly in the field would be able to make a pretty confident call on the basis of jizz alone but the finer details are hard to pin down on some birds. Let's hope it hangs around and allows more pictures - a 'nailed' Caspian Gull would be a first for Lancs. I believe."

Any comments on the Gull? - please email Bill Aspin.