Catherine Holt’s imagination wasn’t running overtime. The Snohomish resident had spotted a towhee with a white head.
"Is there a white-headed towhee?" was the question she left on my answering machine.
"It showed up here last summer. I feed birds all the time, so I’m quite aware of their markings. This was very startling. It had an all-white head that looked like an eagle. Maybe his mama got scared by an eagle," Holt said.
"I saw it feeding young ones out here, (and then) I’ve seen it off and on this winter. It stays to the edge of things, and isn’t quite as bold as regular towhees."
Fright isn’t the explanation, though. The towhee is an example of partial albinism, a condition created by a lack of melanin (pigment) that provides the blacks, grays and browns in feathers. (Carotenoids create the reds, yellows and oranges, and are related to diet; blues and greens are another story entirely.)
Albinism, usually attributed to a recessive gene, can be inherited if both parents have the gene, and can last from molt to molt. Other factors that can cause at least a temporary albinism include injury to the feather follicles, disease, trauma or even an unbalanced diet.
Some ornithologists suspect environmental factor such as toxins could be related to albinism.
The white feathers, regardless of where located on the bird, can throw off the identification process. Partial albinism is more common in darker birds, so we’re more likely to see it in robins, hawks and crows.
Albino birds (all white feathers), which have no pigment, have a higher mortality rate since they’re an easier target for predators, and can have trouble attracting a mate. All of which makes sense, given that the function of feather colors and patterns are for protection and communication.
Although there are recordings of partial albinism in more than 300 bird species, the American robin is the wild bird most reported; all-white birds make up about 7 percent of the birds with albinism, a trait that’s exceedingly rare in wrens and owls.
Speaking of birds, swan conservationist Martha Jordan will be speaking at the Pilchuck Audubon Society’s monthly meeting at 7:30 p.m. Friday at Cascade Crags, 2820 Rucker Ave., Everett.
Snohomish County’s own trumpeter swan expert, Jordan has logged more than 20 years as a swan conservationist. In the past four years, about 850 trumpeters have died in the Whatcom County and Sumas Prairie, B.C., area, and Jordan has been in the thick of trying to track down the source of lead that is killing the birds.
Jordan, the Trumpeter Swan Society, state and federal agencies and other organizations can claim victory in the fight to partially restore Hines Marsh on the north end of the Long Beach Peninsula, where for decades the swans could not seek shelter and food in the marsh because developers had drained it.
Now 60 acres of open water have been restored, and the trumpeters are returning.
Trumpeter swans can be found closer to home. Hundreds of the largest North American swans can be found this month and into March in the Johnson-DeBay Swan Reserve north of Mount Vernon.
Columnist Sharon Wootton can be reached at 360-468-3964 or www.songandword.com.
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