White Stork, Kirkby on Bain GPs, Lincs — © Russell Hayes
It's not something I ever recall seeing before so I searched back through the photo archives so see if I could find any similar birds; and I found this, present in East Yorkshire from 25–28 January 2012:
White Stork, Fraisthorpe, East Yorkshire — © Andy Hood
And this, present at Leven (Fife) on 14th & 15th November 2011:
White Stork, Leven (Fife) – © Jacqui Herrington
It's the same bird! Here's a map of the bird's journey:
Filling in the blanks a bit using other reports of non-photographed White Storks that likely relate to the same bird, we get this rather smart looking map:
But here's the really interesting bit. I trawled back even further and found this photo from Arne (Dorset) on 13th April 2010:
White Stork, Arne (Dorset) — © Mike Coleman
Again, it appears to be the same bird. That's interesting for two reasons. First of all... because it's the same bird! And tracking individual birds is always cool, especially when they travel the length of the country and half way back again. Secondly because it's had its dodgy tail since at least spring 2010. The excellent Grouw Dutch Birding paper (Not every white bird is an albino: sense and nonsense about colour aberrations in birds) says of partial melanism:
Partial melanism sometimes occurs but this is not caused by a mutation but by, eg, disease, mal- nutrition or lack of exposure to sunlight. If these causes are removed, normal feathers will appear during the next moult.White Storks appear to have a complete or near-complete post-juvnile moult from about December–May. Adults seem to have a complete moult starting in summer and finishing in winter (info from here). The photo of the bird in Dorset doesn't appear to show any active moult, nor does it appear to show any retained juvenile feathers so the bird was probably an adult (3+cy) when it was photographed then; though could it be a very early-moulting 2cy? I don't know enough about White Stork moult to be able to comment any further on that! But either way the bird should have undergone two complete (adult) moults since then, which means all of the tail feathers should have been moulted; and, taking what is said in the Dutch Birding paper, that means they should have grown back normally if the cause of the partial melanism had been removed. So, is the bird diseased (and does permanent damage to feather follicles count as disease)? Has the bird for some reason not moulted its tail feathers? Perhaps the black feathers aren't even a result of melanism at all and there's something else causing the tail to be as it is.
And most critically (I joke about the 'most critically' part, obviously), does this odd pattern detract from the odds of the bird being wild?
**Update: I've posted more on this subject here.**