Eh what? A third taxon has been mooted, suggested, put forward for NW Europe. It is genetically separate from carbo and sinensis and appears more closely related to the Japanese or Temminck’s Cormorant Phalocrocorax capillatus. It’s not ‘news’ though it managed to stay off my radar. Good ol’ Brett R. stirred the pot as we sat seawatching at Flamborough. Richard Millington as ever has been very helpfully added more detail. The Sound Approach crew mention it in this book. ( I wonder what norvegicus might sound like?).
The seminal paper is:
Marion & Le Gentil (2006): Ecological segregation and population structuring of the Cormorant Phalacrocorax carbo in Europe, in relation to the recent introgression of continental and marine subspecies.
In a rather fascinating nutshell, whilst exploring the genetic makeup of Cormorants, Marion and Le Gentil discovered that a proportion of the population, especially in Arctic Norway appeared more closely related to the Japanese or Temminck’s Cormorant.
They have named these birds, subspecies nova: norvegicus, explaining:
“…usual P. c. carbo formed two coastal populations, the real P. c. carbo ‘‘C’’ mainly in the western part of the range (United Kingdom, coastal France), and also in Norway and Sardinia, and ‘‘N’’, branched to the Japanese Cormorant P. capillatus and probably isolated by glaciations, mainly present in the Nordic range (Norway, but also on the coasts from Sweden to Brittany), we named P. c. norvegicus.”
“We show the existence of a third group, N, an unexpected new subspecies (we propose to name P. c. norvegicus), mainly present in Norway and Brittany but also in Sweden, Denmark and The Netherlands, all regions near the sea (Fig.4). It is genetically separated from the Western population Cand appears more related to population S … and…to P. capillatus [Japanese Cormorant] ….”
Varanger is near the north-eastern end of the range of old ‘carbo’. It is by extrapolation from the Marion & Le Gentil paper likely to consist of 90% plus norvegicus. Is also represents the Cormorants nearest to the Northeast Passage and the Asian Pacific Rim where Japanese Cormorants could have colonised from.
I wondered if the genes of Japanese Cormorant in norvegicus translate to phenotypic characters. Japanese Cormorants have a carbo-shaped gular pouch angles and in a brief survey seem to have a higher proportion of white filoplumed birds than ‘western’ carbo in breeding dress and more extensive white area behind the bare facial skin. The white filoplumes have a curious look in many Japanese Cormorants, tending to look longer and yet sparser in number, ‘wispy’.
So I dug out my few photos of cormorants in Varanger. Hmmm… interestingly they all had some white filoplumes and some seemed to have more white in the facial pattern than I expect for typical carbo.
It’s very preliminary, but rather fascinating 🙂
Varanger Cormorants (perhaps norvegicus) in March 2012 at Gullfest.
Especially check out the amount of white in the head pattern. Not all had this much white. It would be interesting to see other photos of Cormorants from Varanger. Tormod Amundsen and Anders Mæland are already on the case.
and while exploring the subject, on my local patch:
Cormorants at Flamborough in early January 2015
Above two photos. An interesting ‘carbo-jawed’ individual with some white filoplumes in early January. A norvegicus candidate?
Above. A classic adult sinensis.