Leucistic Pine Siskin, bottom left, had a whitish head and is paler than the normal Pine Siskins above it. Female Purple Finch is on bottom right.
Here it is at the bird bath next to a more normally colored Pine Siskin.
Another view, it only stayed a short time.
We just had a strange Pine Siskin at our feeder with a very light head. This is what is called a leucistic bird. Leucisim in birds, is a genetic mutation that prevents pigment, especially melanin, from being deposited in a normal way on a bird's feathers. Usually the leucistic areas are noticeable on birds with black or brown feathers, as in the above cases. Leucistic birds may have white splotches, or look paler or bleached. This is different than albino birds. Albinism is a genetic mutation that prevents the production of melanin in a bird's body. Albino birds usually appear all white with a pink eye. Scientists are still working out what these two conditions are and how they affect birds.
It is rare to find leucistic birds and even more so to see truly albino birds. With all the Pine Sisikins
showing up this year, people are sure to find some unusual ones.
We often get sent photos of leucistic birds that people find in their yards, to see the photos go here.
Let us know if you find any leucistic birds or unusual Pine Siskins. We have also had a Green Morph Pine Siskin at our feeders in 2009.