In Gargrave recently I spotted this leucistic blackbird…it allowed me a decent photo, which clearly shows the lack of pigmentation especially around it’s head.

Among my huge house sparrow population there used to be several strange looking birds and just a few weeks ago a friend had spotted a whitish blackbird in her Ilkley garden. It seems to be a subject that, understandably, causes some confusion among the non-scientists among us!

What is going on here?

Leucism is not to be confused with albinism, but it often is. An albino bird or indeed any animal including humans, has a complete lack of pigmentation in skin, fur or feathers.

Leucistic birds, on the other hand, can display huge variations in patches of white and normal colouration.

Most of our leucistic garden sparrows tended to be spotted with white patches on breast and among wing feathers and one was almost totally white except for it’s beard. For years now I’ve not seen one so I imagine that local family has died out.

There is a fairly obvious reason for this….both leucism and albinism are genetic conditions and although their siblings and friends didn’t seem to notice or object to their differences, the white feathers mean they cannot merge into the background so are more vulnerable to predation. Very easy pickings for our regular sparrowhawk.

Also dark feathers absorb heat whereas paler feathers reflect heat, so in wintery conditions they can literally freeze to death.

Albino birds suffer from a lack of melanin which makes their feathers structurally weak so they break down and deteriorate. Their poor eyesight (eyes, legs and bill are pink or red) further reduces their chance of survival. Rarity comes at a price!

Back to leucism: it mainly affects the dark feathers so a bird may have lost pigmentation in it’s black or grey feathers but, as with my sparrows, not in the creamy or lighter brown colours...this creates some strange images. That amazingly rare bird you saw with yellow and red bits and white wings was, in fact, a goldfinch after all!

Another common problem in identification is all those variations that many birds indulge to confuse the amateur, like one spotted on Addingham Moorside a few years ago which l sent off to the experts in my excitement. Is it a goshawk, a peregrine, or an, as yet, undiscovered bird of prey? No, it’s a pale young buzzard fooling me.

You live and learn and now, I hope, know a little more about ‘that white bird’ in your garden.