Leucism

Song Sparrow – Melospiza melodia with leucism of its head feathers

Today, as we were driving down from Manomet Point, we stopped at a grassy area between two of the houses on the point. I noticed a couple of small birds foraging in the grass. One of the birds had a white head. I photographed them from the car, using my D500 and Nikon 200-500 mm lens with a 1.4 converter.

The normal coloration of the song sparrow

It turns out that the bird with a white head was a song sparrow with leucism.

Song Sparrow – Melospiza melodia with leucism of its head feathers
Song Sparrow – Melospiza melodia with leucism of its head feathers
Song Sparrow – Melospiza melodia with leucism of its head feathers
Song Sparrow – Melospiza melodia with leucism of its head feathers

Leucism, or leukism, is an abnormal plumage condition caused by a genetic mutation that prevents pigment, particularly melanin, from being properly deposited on a bird’s feathers.

I have read many reports of the leucistic birds and other varieties of animals — the first instance of leucism that I have photographed.

The birds were very accommodating because they were busy feeding and being in between houses, buffered them from the wind.