Adult Black Brant - photographed by Dave Boult at Dart's Farm - 1/12/14.
Dave Boult's superb photos (and video footage) of the Black Brant on the 'Devon Birds' website prompted me to make a comparison with photos of the Black Brant that overwintered on the southern end of the Exe during the autumn/winter 2013/2014. I focused on Lee Collins' stunning portrait of the bird taken at Dawlish warren in March of this year. Of course I fully expected them to be one of the same (black brants are known to show annual site fidelity) but to my surprise they appear to be different birds. I contacted Mike Langman who agreed they seem to differ, pointing out that the extent of white on the upper shoulder area differs markedly, being brighter and more extensive on the Dart's bird. Closer inspection of the white neck 'web' reveals a fuller, crisper pattern on the Dart's Farm bird and the Dart's bird shows a clear intrusion of black that curls up from the belly region into the white mid-flank. The Dawlish bird pictured below doesn't seem to show this, though caution is required here because the shape and pattern of the white flank patch can vary somewhat with posture. Mike suggested the tertials look longer and looser on the Dawlish bird, but with the caveat that this may be age related. It goes without saying that I would appreciate any comments, especially from those people who have seen either bird and/or photographed them, or from anybody with a knowledge of the moult/ageing of brants.
A big thank you to Lee Collins and Dave Boult for allowing me to use their photographs and, of course, to Mike for his thoughts on the bird.
Adult Black Brant - photographed by Lee Collins at Dawlish Warren on 7/3/14.
Little Egret flying to roost at dusk tonight - Mudbank.
Herring Gulls flying to roost.
Hi Matt - Interesting to hear your thoughts on the Black Brant. Always very tricky to establish such things, but would seem some to show some fairly distinct differences, though I am always wary of any moult associated changes - I compared David's video with mine from early Jan this year. See link:http://creamteabirding.blogspot.co.uk/2014/01/black-brant.html
ReplyDeleteHi Matt, excellent comparison there. A quick look at the literature shows that Brents undergo a complete post breeding moult, many seem to migrate whilst undergoing the body moult, whereas others moult completely before heading south. So the Brant could be wearing a completely new set of feathers to last winter, so I don't reckon you can really rule out the fact the differences are simply down to a change in feathers? Apparently some Brents moult the head and neck area again in spring, so it could have gone through two moults at this end of the bird.
ReplyDeleteHi Steve thank you for your comments. I presume that even if it had moulted multiple times it would be replacing white feathers with white and black with black. I think that the basic patterns that we are looking at should be pretty much the same but there are quite distinct differences. I guess with multiple brants knocking around with various Brent flocks it wouldn't be too out of the question to get two individuals in successive winters and I haven't heard news of the Ferrybridge bird(s) for a while. Who knows? Cheers,
ReplyDeleteMatt (not Maisie).
Hi Matt, yes I suppose so but feather growth can be affected by different factors so wouldn't bank on feathers being replaced like for like. I guess difference could be an age thing - most of the features seem brighter or bigger on this winters bird, so could it have been in its second winter last winter, and now third? Or like you say, is it one of the Fleet birds? They had three a couple of winters ago, but now only one.
ReplyDeleteHi Matt, I just came across this post and thread. I wonder if the head profile of this bird may also support the 'two bird theory'. I noticed this immediately on seeing it at Exminster Marsh and it appears to be consistent on subsequent sightings. I notice you comment on it to on your blog post when you first found it. The bill appears small and the long flat forehead forms a distinct angle with a flat crown. The photo above shows this too. If this is genuine and not an artefact of missing or displaced feathers then I find that difficult to reconcile with the head shape of the 2013/14 bird. Doesn't look conclusive but maybe indicative of two birds. James
ReplyDelete