white goldfinch...

 Hi Dani Welcome to the forum.

I would identify the bird you saw as a Leucistic Goldfinch.

There is a difference of opinion and definition of Leucism and Albinism between, "ordinary birders" and scientists. In the scientific circles there seems to be little doubt that the term "albino" is only used if there is a complete lack of pigmentation, including soft parts.

Leucism describes the various forms where there is a lack of pigmentation, but not complete. Do note that this lack can be complete in areas and still be considered leucistic, as long as other areas do have pigmentation to some extent.

Hence, "partial albino" is not used at all.

This also concurs with the ideas taught in the biology classes in universities.

Scientifically, a bird with white patches is, in fact, leucistic.

However, this is where "ordinary birders" differ, I think in part because the term leucistic only entered the scene fairly recently in these circles.

Previously, when not knowing the term leucistic, it would be logical to use the wellknown albino in a modified way; i.e. "partial albino".

However, then "leucistic" enter the scene and the confusion appears to be total.

Albino refers only to things that have two recessive genes and, therefore, no pigment anywhere.

As leucism is a spectrum between white and normal, any odd white feathers are leucistic. This could be genetic, or indeed possibly from infection/trauma and diet may also contribute to abnormalities.

If you say 'albino' people think of a pure white bird with pink eyes (no pigment anywhere), and if you say 'leucistic' then most people think of a pale, washed out bird where the colouring is diluted.

If you say 'partial albino' then people know what you mean - a bird with white patches. As such, they cannot be 'partial albino' as they do not have both recessive genes.

Leucism is a condition characterised by reduced pigmentation in animals and humans. Unlike albinism, it is caused by a reduction in all types of skin pigment, not just melanin.

Leucism is kind of the opposite of melanism.

The following links will give you the best information on Leucism

 http://en.wikipedia.org/wiki/Leucism

 http://listserv.arizona.edu/cgi-bin/wa?A2=ind0011c&L=birdband&T=0&F=&S=&P=778

 Regards Buzzard