Black Brant Branta (bernicla) nigricans
Brent Geese belonging to the North American and east Siberian form nigricans are occurring in Norfolk with increasing regularity - several individuals are now recorded every winter.
Some of the Black Brants that winter in western Europe have produced hybrids with Dark-bellied Brent Geese, and this makes their identification far more difficult. Separating pure Black Brants from pure Dark-bellied Brent Geese is fairly straightforward but hybrids can be much less so. Some hybrids can be reasonably easy, but others may be much more like either parent species - and to complicate matters further backcrossed hybrids must surely occur as well.
Over the years I have identified a number of Black Brant-like birds as hybrids on account of the back and belly not being dark enough. Whilst this was undoubtedly valid in some cases I had not always appreciated the extent to which these parts can vary in appearance according to light, and it may well be that I have misidentified some perfectly good Black Brants as hybrids. Under certain light conditions the black on a Black Brant's back and breast can be so dark that it doesn't contrast at all with the black neck, but on the same bird in different lights (including bright sunshine) these parts can contrast quite strongly with the neck (although they should always appear darker than on Dark-bellied Brent Geese in the same conditions).
The extent of dark feathering within the white flank patch is certainly variable with all forms of Brent Goose and the precise extent of the white neck collar is also variable. In both cases there may be little overlap with pure Dark-bellied Brent Goose but I have come to believe that a slightly less prominent white flank patch than on the most obvious birds, or a white neck collar that doesn't reach quite so far round the back of the neck as it does on some birds, are not probably not good evidence of a hybrid identity.
In view of the above I have now lost confidence in the labelling of several birds I'd originally got down as hybrids, and although I still think some of them were hybrids (I'm sure a few were) I think several of them were more likely pure birds after all. I haven't yet developed a full understanding of the limits between pure and hybrid birds - more study and more learning is needed!
%20L.JPG "Black Brant, Wells, 26-Feb-07") |
%20L.JPG "Black Brant, Wells, 26-Feb-07") |
%20L.JPG "Black Brant, Wells, 26-Feb-07") |
%20L.JPG "Black Brant, Wells, 26-Feb-07") |
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adult Black Brant (with Dark-bellied Brent Geese), Wells (Norfolk, UK), 26th February 2007
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%20L.JPG "Black Brant, Wells, 11-Dec-07") |
%20L.JPG "Black Brant, Wells, 11-Dec-07") |
%20L.JPG "Black Brant, Wells, 11-Dec-07") |
%20L.JPG "Black Brant, Wells, 11-Dec-07") |
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adult Black Brant (with Dark-bellied Brent Geese), Wells (Norfolk, UK), 11th December 2007
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%20L.JPG "Black Brant, Wells, 19-Nov-04") |
%20L.JPG "Black Brant, Wells, 19-Nov-04") |
%20L.JPG "Black Brant, Wells, 19-Nov-04") |
%20L.JPG "Black Brant, Wells, 19-Nov-04") |
%20L.JPG "Black Brant, Wells, 19-Nov-04") |
%20L.JPG "Black Brant, Wells, 19-Nov-04") |
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adult Black Brant (with Dark-bellied Brent Geese and hybrid young), Wells (Norfolk, UK), 19th November 2004
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%20L.JPG "Black Brant, Titchwell, 1-Nov-08") |
%20L.JPG "Black Brant, Titchwell, 1-Nov-08") |
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adult Black Brant, Titchwell (Norfolk, UK), 1st November 2008
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%20L.JPG "Black Brant, Titchwell, 9-Feb-08") |
%20L.JPG "Black Brant, Titchwell, 9-Feb-08") |
%20L.JPG "Black Brant, Titchwell, 9-Feb-08") |
%20L.JPG "Black Brant, Titchwell, 9-Feb-08") |
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adult Black Brant (with Dark-bellied Brent Geese), Titchwell (Norfolk, UK), 9th February 2008
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%20L.JPG "Black Brant, Stiffkey, 21-Mar-09") |
%20L.JPG "Black Brant, Stiffkey, 21-Mar-09") |
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adult Black Brant (with Dark-bellied Brent Geese), Stiffkey (Norfolk, UK), 21st March 2009
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%20L.JPG "Black Brant, Salthouse, 3-Jan-11") |
%20L.JPG "Black Brant, Salthouse, 3-Jan-11") |
%20L.JPG "Black Brant, Salthouse, 3-Jan-11") |
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adult Black Brant (with Dark-bellied Brent Geese), Salthouse (Norfolk, UK), 3rd January 2011
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%20L.JPG "Black Brant or hybrid, Wells, 22-Nov-06") |
%20L.JPG "Black Brant or hybrid, Wells, 22-Nov-06") |
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adult Black Brants or Black Brant x Dark-belled Brent Goose hybrids (with Dark-bellied Brent Geese), Wells (Norfolk, UK), 19th November 2004 - at the time I felt that both of these were hybrids, but I am no longer certain. I remain more confident about the next bird below which was in the same flock:
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%20L.JPG "Black Brant x Dark-bellied Brent Goose, Wells, 22-Nov-06") |
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adult Black Brant x Dark-belled Brent Goose hybrid (with Dark-bellied Brent Geese), Wells (Norfolk, UK), 19th November 2004 - even with a revised view of how to identify hybrids I am still reasonably sure this one is a hybrid
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%20L.JPG "Black Brant, Wells, 19-Feb-07") |
%20L.JPG "Black Brant, Wells, 19-Feb-07") |
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adult Black Brant, Wells, 19th February 2007
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%20L.JPG "Black Brant, Wells, 19-Feb-07") |
%20L.JPG "Black Brant or hybrid, Wells, 19-Feb-07") |
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adult Black Brant (left: the same bird as above) and possible adult hybrid Black Brant x Dark-bellied Brent Goose (right), Wells, 19th February 2007 - at the time I felt the right hand bird was a hybrid but I am no longer certain of this
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%20L.JPG "Black Brant, Wells, 7-Dec-08") |
%20L.JPG "Black Brant, Wells, 7-Dec-08") |
%20L.JPG "Black Brant hybrid, Wells, 7-Dec-08") |
%20L.JPG "Black Brant hybrid, Wells, 7-Dec-08") |
%20L.JPG "Black Brant hybrid, Wells, 7-Dec-08") |
%20L.JPG "Black Brant hybrid, Wells, 7-Dec-08") |
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adult Black Brant or hybrid, Wells (Norfolk, UK), 7th December 2008 - this bird looked quite different in different conditions and angles to the light: at times it looked pretty good and at other times it looked dire!
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%20L.JPG "Black Brant or hybrid, Burnham Overy, 31-Jan-09") |
%20L.JPG "Black Brant or hybrid, Burnham Overy, 31-Jan-09") |
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adult Black Brant or hybrid, Burnham Overy Marsh (Norfolk, UK), 31st January 2009
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%20L.JPG "Black Brant, Wells, 14-Feb-08") |
%20L.JPG "Black Brant, Wells, 14-Feb-08") |
%20L.JPG "Black Brant, Wells, 14-Feb-08") |
%20L.JPG "Black Brant, Wells, 14-Feb-08") |
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adult Black Brant, Wells (Norfolk, UK), 14th February 2008
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%20L.JPG "Black Brant or hybrid, Wells, 22-Jan-10") |
%20L.JPG "Black Brant or hybrid, Wells, 22-Jan-10") |
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adult Black Brant x Dark-bellied Brent Goose hybrids, or Black Brants, Wells (Norfolk, UK), 22nd January 2010 - I thought these were both hybrids at the time but I am not sure!
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%20L.JPG "Black Brant, Wells, 13-Jan-12") |
%20L.JPG "Black Brant, Wells, 13-Jan-12") |
%20L.JPG "Black Brant, Wells, 13-Jan-12") |
%20L.JPG "Black Brant, Wells, 13-Jan-12") |
%20L.JPG "Black Brant, Wells, 13-Jan-12") |
%20L.JPG "Black Brant, Wells, 13-Jan-12") |
%20L.JPG "Black Brant, Wells, 13-Jan-12") |
%20L.JPG "Black Brant, Wells, 13-Jan-12") |
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adult Black Brant, Wells (Norfolk, UK), 13th January 2012 - this appeared perfect in some lights but much less impressive in other lights - I am not 100% certain it was not a hybrid
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%20T.JPG "Dark-bellied Brent Geese")
%20T.JPG "Pale-bellied Brent Geese")
%20T.JPG "Red-breasted Goose")
%20T.JPG "Barnacle Goose")