Over the last two weeks we've had a birding bonanza, with a flurry of novel bird sightings in our yard. First we spotted a black-throated gray warbler.
That didn't stay long, but a few days later we had a sweet little orange-crowned warbler who decided our back patio was a good place to find food. Its yellow belly and olive-green back really stood out. It would hop about between the flower pots catching insects.
Yesterday a female black-headed grosbeak came to visit our feeder. She has a striking black and white-striped head and a large beak, strangely out of proportion for the rest of the bird.
A few days ago my son noticed a pale bird visiting the feeder. With a string of new birds showing up, we excitedly pulled out the bird books. Nothing really seemed to fit, and the bird did look familiar. Very familiar. In fact it looked like all the house finch females that have come to our feeder for years.
You decide. The pale bird is on the right, a regular female house finch on the left.
We think she is an example of leucism, a bird or mammal with abnormally pale coloration.
Project Feeder watch has an article on Plumage Variations: Albinism or Leucism?
Stokes birding blog also has an article on leucistic birds.