Winter Birding: Cian's thoughts on the 'Continental' Cormorant

Ever since the beginning of 2015 a major part of my birding life has been dedicated to one of my favourite birds, the Great Cormorant and more to the point the two sub species of it which occur in British waters, ssp carbo & ssp sinensis. When I first started out with Cormorants I like many believed that every Cormorant which had a gular pouch (the yellow skin at the base of the bill), over 90 degrees was to be classed as that of the Continental race of Great Cormorant ssp Sinensis, not the Atlantic race of ssp Carbo which is what were more familiar with here in the UK & Ireland. Yet in fact over the last year or so I have learned that this is not the case, infact its far from it; So here's my thoughts on the Identification of 'Continental' Great Cormorant in Ireland. Although I have not yet got a chance to study these bird's abroad I hope to soon and have been I contact with experienced Birders who have.

'Atlantic' Great Cormorant (Phalacrocorax carbo carbo), Cian Cardiff
Above is a perfect example of the classic 'Atlantic' Great Cormorant (ssp Carbo), the only feature on this bird that rules it out being a 'Continental' bird is that the angle of the Gular is far the small for a 'Sinensis' type bird. But then is the gular the feature on which we can safely Identify 'Continental' bird's? Is the gular pouch itself enough to go on! Well I don't believe so.

'Atlantic' Great Cormorant (Phalacrocorax carbo carbo), Cian Cardiff
At first this adult Cormorant appears to fit the bill for that of a 'Sinensis' bird and with what knew at the time it certainly seemed to be the case, but looking a little more carefully the bird was infact the is actually the size of Carbo! After a couple of weeks of watching the varies sizes of 'Carbo' I made up my own mind that size alone wasn't a clear cut feature as it was once thought. Now the only feature left on this bird was it's gular which fitted the 'Sinensis' code so to speak, text book! But again it left me wondering are we really able to identify these bird's without DNA testing ? Another feature thought to be found on any good 'Sinensis' type is a short but slim neck, but from my personal observations I've noticed that every now and again 'Carbo' can also shows this feature, yet another feature ruled out. But now we conclude on the last and final feature for this post as we reach the bill length; for 'Sinensis' it is generally believed that they a have a longer and much more slimmer bill compared to that of 'Carbo' which are meant to have a shorter and ticker bill than Sinensis. But again from my observations there doesn't appear to be to huge variation in 'Carbo' bird's unlike that of 'Sinensis'.

'Continental' Great Cormorant (Phalacrocorax carbo sinensis) Elliot Montieth
I kept on asking these questions, I began to learn and discover more and more about the behaviour of Cormorants both 'Atlantic' and 'Sinensis' types. The majority of 'Sinensis' types were rather compact, sleek and hard to get close to. Again not a feature but just noted in 'Continental' bird's but an interesting fact I picked up along the way. As I have researched 'Continental' bird's on the internet I found some cracking images of what looked to be 'Sinensis' type bird's. But how much overlap could there be in both types and how often do they interbred ?

Great Cormorant ssp, Cian Cardiff
Here's yet another image of a prime 'Sinensis' candidate, this being an Adult type. This bird was very stumpy and had a perfect gular pouch, but again I've observed tonnes of bird's like this in Ireland and still ask myself the question are these bird's the real deal? Is the answer yes and no ? Some are great looking where as others not so much due to the gular angle just being off or it being a huge bird!

Great Cormorant ssp, Cian Cardiff
These two bird's (above and below) were photographed from a headland in Co. Wexford were Cormorants bred during the summer months and whilst on a trip there earlier this year I picked out these two which are the best 'Sinensis' candidates I could find. Both bird's were very small, but flight pictures aren't a safe method for the identification of races, but I later saw these on the deck also but distant. One important factor to note while looking at what you think might be a 'Continental' bird is to watch the gular to see if it changes shape in a dramatic form, if it doesn't then it is thought that this is a good feature of 'Sinensis'. A bird with a gular angle of anything less than 70 dg is thought to be a 'Carbo', though I have noted Cormorants with gular pouches with a 100 dg or even 120 dg angle which is a great sign of a so called real 'Sinensis'.

Great Cormorant ssp, Cian Cardiff
As I could go on and on about Irish Great Cormorants all day I will conclude here; in my thoughts I believe that the so called real 'Continental' bird's do breed in Ireland and hybridisation does occur in Ireland may it be in either inland or coastal colonies. I believe that we need to focus more on are inland population of Cormorants to give use the answers we need to safely identify this fascinating race outside of its normal breeding areas on the continent. Another I'd add is that don't always pay attention to some books that say all 'Sinensis' birds Spring and Summer have completely silver necks & head as in increasing about of 'carbo' birds are now starting to show this eye catching feature.

So again, get out and start to photograph these very much under rated & under watched bird's and please do let use know what your thoughts are on what in our minds is one of the most interesting of all races.

Keep learning, Regards for now.
Cian Cardiff & Elliot Montieth


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