BIRD COLUMN FOR August 17, 2003
By Benjamin P. Burtt
Now and then albino birds are reported. These are birds that have white feathers in place of the usual colors of their normal plumage.
These white feathers may cover the whole bird, but usually they only replace part of the feathers. Such a bird is said to have partial albinism.
Such a condition is quite rare,. Two scientists who studied birds by capturing and banding them, handled some 30,000 birds over a period of 10 years. Only 17 of those birds had albinism to any degree. This is less than half of 1%.
For the average person who knows the common birds around his home, a partially albino bird is unlike any bird ever seen before. We tend to identify birds by the color of the different parts of the body. Quite naturally, the observer assumes that the bird is some new species that wandered by.
If a bird is carefully described to me, I can usually say that there is no bird around here that normally has that plumage and that it is probably some common bird with abnormal plumage colors.
Once you realize that it is probably a common bird then you can consider the shape and size and ask what species it might it be? You can also ask, what birds are mingling with it?
Last year I was contacted by Don and Marge Svedman of Manlius who had a partially albino female cardinal in their yard.
When it first appeared in February of 2002, the male was feeding the albino as they do in courtship at that time of the year. It is still around their property now and a photograph taken by Svedman appears with todays column.
This beautiful bird is a partially albino female cardinal that has been living in Manlius for two years. (Courtesy of Don Svedman )
I am very pleased to be able to share this image with you for very few people ever have a chance to see such a bird.
You will notice that there is red in all the usual places where red appears on a female cardinal. It is on the tip of the crest, on the wings, tail and beak. In other words the red pigment was not altered. What is missing is the normal brown color of the female and those feathers have no pigment and appear white.
This is the result of a genetic change and a chemical is missing that is needed to make the colored pigment. As far as we know, this bird had this plumage when it first fledged.
In some cases, a patch of white feathers will appear on a bird that up to then has had its usual colors. This can be caused by an injury, some dietary deficiency or some hormonal change at the time the feathers are developing.
A British bird bander trapped the same blackbird every year and in the fifth year, the bird had patches of white all over its body that were not there previously. Another became progressively white over a three year period.
Totally albino birds are those in which all the feathers are white. The eyes, leg and bill will have a pinkish tinge because the color of the blood shows through when there is no pigment in the tissue.
Such birds are extremely rare in the wild. They are conspicuous and more likely to be caught by predators. They often have weak eyesight and the lack of pigment makes the feathers brittle. Such feathers often wear out before the next molt and the bird will not be able to fly well.
One other problem when there are many white feathers, is that the bird is not recognized by prospective mates or others of its own kind.
One scientist reported a pure albino female red-winged blackbird in an immense September flock that was chased repeatedly by its companions. It always returned to the flock to be chased again.
The Manlius female cardinal shown in the illustration apparently is recognized as a cardinal by the male. I suspect that it is the red color in all the right places that identifies her and whether the rest of the bird is the usual brown or whether it is white apparently does not matter.
With a few species, it is normal for the plumage to become white and then change back each year. The ptarmigan is a brown, grouse in the summer that gradually becomes white each fall. This is not albinism. It lives in the open country far north beyond the limit of the trees. It is also found at high altitude in the Rocky Mountains.
The white plumage makes the bird hard to see in the winter snow. In the summer it becomes brown again. That color then matches the bare and rocky terrain where it breeds.
One time on a family summer trip to the Rockies years ago, we all watched a ptarmigan slowly walking across a rocky slope only 20 feet away. When it stopped moving, it blended so well with the background that it just disappeared!
By Benjamin P. Burtt
Now and then albino birds are reported. These are birds that have white feathers in place of the usual colors of their normal plumage.
These white feathers may cover the whole bird, but usually they only replace part of the feathers. Such a bird is said to have partial albinism.
Such a condition is quite rare,. Two scientists who studied birds by capturing and banding them, handled some 30,000 birds over a period of 10 years. Only 17 of those birds had albinism to any degree. This is less than half of 1%.
For the average person who knows the common birds around his home, a partially albino bird is unlike any bird ever seen before. We tend to identify birds by the color of the different parts of the body. Quite naturally, the observer assumes that the bird is some new species that wandered by.
If a bird is carefully described to me, I can usually say that there is no bird around here that normally has that plumage and that it is probably some common bird with abnormal plumage colors.
Once you realize that it is probably a common bird then you can consider the shape and size and ask what species it might it be? You can also ask, what birds are mingling with it?
Last year I was contacted by Don and Marge Svedman of Manlius who had a partially albino female cardinal in their yard.
When it first appeared in February of 2002, the male was feeding the albino as they do in courtship at that time of the year. It is still around their property now and a photograph taken by Svedman appears with todays column.
This beautiful bird is a partially albino female cardinal that has been living in Manlius for two years. (Courtesy of Don Svedman )
I am very pleased to be able to share this image with you for very few people ever have a chance to see such a bird.
You will notice that there is red in all the usual places where red appears on a female cardinal. It is on the tip of the crest, on the wings, tail and beak. In other words the red pigment was not altered. What is missing is the normal brown color of the female and those feathers have no pigment and appear white.
This is the result of a genetic change and a chemical is missing that is needed to make the colored pigment. As far as we know, this bird had this plumage when it first fledged.
In some cases, a patch of white feathers will appear on a bird that up to then has had its usual colors. This can be caused by an injury, some dietary deficiency or some hormonal change at the time the feathers are developing.
A British bird bander trapped the same blackbird every year and in the fifth year, the bird had patches of white all over its body that were not there previously. Another became progressively white over a three year period.
Totally albino birds are those in which all the feathers are white. The eyes, leg and bill will have a pinkish tinge because the color of the blood shows through when there is no pigment in the tissue.
Such birds are extremely rare in the wild. They are conspicuous and more likely to be caught by predators. They often have weak eyesight and the lack of pigment makes the feathers brittle. Such feathers often wear out before the next molt and the bird will not be able to fly well.
One other problem when there are many white feathers, is that the bird is not recognized by prospective mates or others of its own kind.
One scientist reported a pure albino female red-winged blackbird in an immense September flock that was chased repeatedly by its companions. It always returned to the flock to be chased again.
The Manlius female cardinal shown in the illustration apparently is recognized as a cardinal by the male. I suspect that it is the red color in all the right places that identifies her and whether the rest of the bird is the usual brown or whether it is white apparently does not matter.
With a few species, it is normal for the plumage to become white and then change back each year. The ptarmigan is a brown, grouse in the summer that gradually becomes white each fall. This is not albinism. It lives in the open country far north beyond the limit of the trees. It is also found at high altitude in the Rocky Mountains.
The white plumage makes the bird hard to see in the winter snow. In the summer it becomes brown again. That color then matches the bare and rocky terrain where it breeds.
One time on a family summer trip to the Rockies years ago, we all watched a ptarmigan slowly walking across a rocky slope only 20 feet away. When it stopped moving, it blended so well with the background that it just disappeared!
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