Thursday, January 20, 2011

A Winter Commute’s Glorious Diversion


As I drove to work from my little bedroom community into Fayetteville, AR this winter, I spotted what I at first thought was a white plastic bag caught in the top of a tree about forty yards from the highway (known generically in these parts as “a WalMart bag”). After a classic double-take, I realized it was a lone bird—absolutely pure white—sitting in this lone tree in a pasture. It was obviously a raptor of some type, but the only pure white raptor I knew of was a Snowy Owl which, according to my bird book, does migrate from the Arctic in winter as far south as Missouri. A quick internet search informed me that Snowy Owls have been sighted in Arkansas three times over the years. But this just didn’t seem right.
This is as close as it ever let me come.
I saw the same bird in the same tree two more times and again in some riparian woods lining the Middle Fork of the White River about a hundred yards from the highway. Still, these were only observations at 55 mph without binoculars. One Saturday, I grabbed my binoculars, bird books and camera, and drove to the spot that I’d seen the bird before. I was better prepared this time, but no bird. On a lark, I decided to drive down a side road to the back of a subdivision which butts up against pastures and scattered woodlots along the Middle Fork. As I pulled into the last cul-de-sac there was the bird: facing me from seventy-five yards away sitting in an old dead tree behind a house. I snapped a preliminary photo (through my windshield), and grabbed my binocs. It looked like a pure white hawk. It had bright yellow feet (talons). I then slipped open the car door and snuck around the side of the house to try to out-flank the bird. Of course, being a raptor, the bird’s eyesight is much better than my own, maybe even with my binoculars, I don’t know. The bird had flown.
The next week I tried again. Trolling again down the side road, I quickly spotted the bird in a tree at the edge of a 2-acre woodlot where it gives way to a pasture which runs through the Middle Fork valley. I decided to hop the fence and sneak through the woods to try to get a close look. I saw some interesting things in the woods, like this pretty orange Bolete—a wood-rotting mushroom fungus with pores instead of gills. But the bird knew what I was up to and was gone by the time I emerged on the other end.



And then I heard the call.
A long, single, descending “screeeeee ….” rang out from the other side of the pasture.  I made my way to that side of the woods and again heard the call. Sure enough, in that direction, was the brilliant white bird sitting in a tree on the other side of the pasture. It was a hawk call, probably a red-tail.  As I began to walk across the pasture, the hawk took flight, cursing me with scree! Up until this moment, I had only seen the hawk from the front. As he/she flew away, from my right to left, I could see the wings and sides—pure blazing, beautiful white! All over!
Now I can spot the bird from quite a distance because of the color (or lack thereof).  But I have given up harassing the poor thing when I don’t even have a spotting scope to get a better look. I googled pure white hawks and found a website with some really nice photos of albino hawks that look just like my Middle Fork friend. Unfortunately, the site did not give permission to re-use the images, but here are three others from other sites:
white Red-Tailed Hawk, Albany, NY (R. Guthrie)
white Red-tail in rehab center
How gorgeous is this white Red-tail!
 I also emailed an ornithologist at the University of Arkansas, Joe Neal, about what I was seeing. He told me that a local birder from Round Mountain, near my town, had been watching this bird for years. Fifteen years to be exact! Joe put me in touch with Jim Morgan who said that the bird has been wintering here since at least 1995, but normally stays up-river about a quarter mile or more, away from the highway and more out of sight.
There has been some discussion about whether this is a red-tail or a red-shouldered hawk. The call is that of a red-tail (a red-shouldered hawk will cry out several times in a row). And Jim saw it once, backlit by the sun, revealing a faint, pink band on the tail like a red-tail. The biggest question is whether it is a true albino or is very leucistic. Joe Neal says that even an albino can have color in the feet and bill. But the eyes will be pink. I can’t get close enough to see the eye color on this bird. Leucism is a genetic trait caused by separate genes those that cause albinism. Leucism can be complete or partial, and can affect all kinds of critters, not just birds. I have a musician friend who has small leucistic patches of white amongst his generally dark, brown hair.
Here are some further distinctions from about.com: Albinism is another genetic condition that can turn a bird’s plumage pale, but there are distinct differences between albino and leucistic birds. Leucism affects only the bird’s feathers, and typically only those with melanin pigment – usually dark feathers. A leucistic bird with different colors may show some colors brightly, especially red, orange or yellow, while feathers that should be brown or black are instead pale or white. Some leucistic birds, however, can lose all the pigment in their feathers and may appear pure white.





Albinism, on the other hand, affects all the pigments, and albino birds show no color whatsoever in their feathers. Furthermore, an albino mutation also affects the bird’s other pigments in the skin and eyes, and albino birds show pale pink or reddish eyes, legs, feet and a pale bill, while leucistic birds often have normally colored eyes, legs, feet and bills.


While leucism can be unusual and exciting for a birder to see, birds with the condition face special challenges in the wild. Lighter plumage may rob the birds of protective camouflage and make them more vulnerable to predators such as hawks and feral cats. Because plumage colors play an important role in courtship rituals, birds with leucism may be unable to find strong, healthy mates. Melanin is also an important structural component of feathers, and birds with extensive leucism have weaker feathers that will wear out more swiftly, making flight more difficult and eliminating some of the bird’s insulation against harsh weather. White feathers also reflect heat more efficiently, which can be fatal for birds that rely on sunbathing and solar radiation for heat in northern climates.
While I can’t vouch for his/her’s sex life, our Middle Fork red-tail seems to be doing quite well and has been for at least 15 years  . . .  a glorious bit of God’s green earth,  and a real treat for me--spicing up an otherwise dull commute on a winter’s morning.

1 comment:

  1. Great tale! I wish I hadn't stopped in the middle of reading your blog to find out what leucism means. Kicked myself when I read your explanation a couple sentences later. What a fun discovery, Bob. Good for you for being curious.

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