Odd Colouring

[baturn]

This is a female House Sparrow. I'm wondering what might cause the white wing feathers.
Anyone?

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[john.margetts]

Partial albinoism is quite common in birds. You are more likely to see it in blackbirds, but that is because the colour of blackbirds makes it more obvious.

 

[baturn]

Thanks, I suspected as much, but found nothing with my rather lame search attempt.