Piebald...

I took Rosie to Ferry Meadows today, and although it took a long time, she made it into the lake, where she was joined by this piebald carrion crow. He was very tame and seemed rather fascinated by her, perhaps because she's too old now to chase anything. The crow drank from the lake and then started picking up leaves and other small objects, and hopped after Rosie, almost as though he wanted to play!

Leucism is an abnormal plumage condition caused by a genetic mutation that prevents pigment, particularly melanin, from being properly deposited on a bird’s feathers. As a result, the birds don't have the normal, classic plumage colours listed in field guides, and instead the plumage has changes, including white patches where the bird should not have any. This phenomenon is quite frequent in our local crow population.

The degree of leucism, including the brightness of the white and the extent of pigment loss, will vary depending on the bird’s genetic makeup. Birds that show only white patches or sections of leucistic feathers – often in symmetrical patterns – are often called pied or piebald birds, while birds with fully white plumage are referred to as leucistic birds.