UAF FARM FIELDS — Gliding in with their wings folded like paper airplanes, nine Canada geese drop their paddle feet and prepare to land in a corner of this cleared plain.
On this early fall day, the birds could use an air traffic controller. Their landing zone of barley stalks is clogged with the rusty brown bodies of sandhill cranes, strutting like Mick Jagger.
The geese flap in and trot to the dirt, joining the cranes and a few other species of goose and duck in this stopover point between summer and winter. In these farm fields that are reminiscent of Wisconsin but feature treeless space rare in Interior Alaska, hundreds of birds are pausing. After a summer on buggy tundra, the birds rest here on one of the first steps of a journey that will take them as far as Mexico.
Most of the birds in the fields are cranes, bent over feeding on grains and walking. They are teeming, abundant. With a squint, they look like wildebeests on the savannah.
For some reason, a few birds jump into the air. With mighty flaps of wings that spread six feet, hundreds of other cranes join them. With the rising from the yellow field comes a noise so loud the birds steal the soundscape from passing water trucks on the Parks Highway and the blat of small aircraft on floats passing overhead.
How to describe the sound of a crane? One field guide writer suggests “a trumpeting, rattling gar-oo-oo.”
Good for him for trying, but describing a crane’s (or any bird’s) voice with words is a subjective exercise. Your gar-oo-oo is my shoo-be-do.
The crane sound is a Pleistocene vibration of cool fall air. Watching these birds kettle up and especially hearing them, it’s not hard to imagine the mammoths, wild horses and American lions that once strode beneath the same pleasant racket.
All bird songs are the result of miraculous plumbing. The sandhill crane is one of the loudest birds, with a sound estimated by those who studied it to be audible more than two miles away.
In his comprehensive bird-migration book, “Living on the Wind,” Scott Weidensaul wrote of the machinery that makes the crane so loud:
“Their secret is coiled like a snake inside their chests. Rather than simply connecting the lungs to the outside world, an adult crane’s trachea, or windpipe, loops around the breastbone, forming a tube which, if stretched out, is almost as long as the bird itself.”
Cranes stand four feet tall. That extra-long vocal tube wound inside them amplifies, deepens and modulates their sounds. A few other birds, including trumpeter swans, have a similar stretched windpipe that helps their voices carry farther.
For perhaps a week, the university farm fields and Creamer’s Field Refuge in Fairbanks will feature the timeless call of the changing season. Soon, maybe tonight, a crane will croak into the air. Its neighbors will follow, until the birds rise in an inverted cone of swirling feathers and flesh. Thousands of feet above the scratches in the Fairbanks landscape, the birds will pour southward, taking their ice-age soundtrack with them.
Ned Rozell for UAFGI
Alaska Science Forum. Since the late 1970s, the University of Alaska Fairbanks’ Geophysical Institute has provided this column free in cooperation with the UAF research community. Ned Rozell is a science writer for the Geophysical Institute. Posted by Ned Rozell on September 01 2016 http://www.gi.alaska.edu/alaska-science-forum/pleistocene-sounds-season-0
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