White hummingbird spotted
■ The rare white bird is not albino.
Hummingbirds are clearing out of Northwest Arkansas and people with feeders are seeing birds on the run — including a rare leucistic hummingbird.
Bella Vista residents Jack and Sue Fellenzer feed birds of all sorts and have five hummingbird feeders that attract enough birds that they need to refill them with incredible regularity —sometimes daily.
They were surprised, Sue Fellenzer said, to see a white hummingbird among all the green feathers. They started reading up on white birds, only to discover this particular bird is what’s labeled leucistic — which is to say it has white feathers but is not an albino.
Bill Hilton Jr., executive director of Hilton Pond Center for Piedmont Natural History in York, S.C., said that the visible difference between an albino and a leucistic bird is that a leucistic bird will have some color, be it a black or tan beak or spots or splotches in the feathers. Both, he said, are the result of genetic anomalies.
“The only pigment that you actually see in a true albino is the hemoglobin pigment that is in the blood, so that’s why it looks pink,” he said. “The rest of the birds, including the leucistic ones, have melanin pigment …. In leucistic birds, there’s a very little amount of the melanin that shows.”
Melanin is the same pigment that causes people to have dark hair or tanned skin, he said. In leucistic birds the appearance may be highly variable — some may have pure white feathers, while others have splotches, speckles or spots. Their feet and bill may also vary, he said, from black to a brownish color.
Melanin is also a structural pigment, he said, which makes feathers stronger. He said that
he has never seen a leucistic hummingbird return after banding it. His hypothesis is that, with the lack of melanin, the birds’ feathers are not surviving migration.
“It’s a long way to Central America,” he said, where hummingbirds migrate for the winter.
He’s heard of one documented case in California where a leucistic bird returned year after year, he said, but the hummingbirds there do not migrate.
There could be other factors, he said. Birds showing these genetic differences,
he said, may also have other problems — they could be more susceptible to disease, for example.
In any case, he said, the birds are not surviving to pass on their genes and the result is very few of them are around. It would be impossible, he said, to discern the total proportion of the hummingbird population they make up, but he’s been studying hummingbirds — particularly the rubythroated hummingbird through his project, Operation Ruby Throat, which can be viewed at rubythroat. org — since 1984. He has only had a few of these birds reported to him each year.
Douglas James, who recently retired from his post as a professor of zoology at
the University of Arkansas, said he looked through documentation to try to discern approximately how often a bird hatches albino or leucistic. Finding proper data, he said, is all but impossible.
“Albinism in birds isn’t very high,” he said. “The incidence for birds in general … is less than 1 percent.”
But hummingbirds are worth paying attention to, he said. In Arkansas, there’s significant variety — more than 20 species, he said.
“We’ve got a tremendous number of hummingbird species in Arkansas right now.”
He leaves his feeders out all year, he said, because even as migration season winds down there may be more birds swinging
through the area, and they benefit from a chance to refuel.
Jack Fellenzer said he’s started to see hummingbirds clear out — there are maybe four or five visiting his yard now, though a couple weeks ago it was closer to 20. They usually disappear altogether around the first or second week of October, he said.
The white-feathered avian stuck around for about four or five days, he said, before moving on with his migration.
“We’re looking forward to next year to see if he shows up again,” Fellenzer said. “Might have been just a fluke, but you can tell a lot of these little guys are repeaters.”