Cranes by telemetry
OTHELLO - In long bygone days, say before 1492, the continent was a-flutter with so many wings that today we can hardly imagine what the skies were like. To wit, of large birds there were literally millions: cranes, and swans, too, crossing mountains and basins wild.
So says International Crane Foundation biologist Gary Ivey, of Bend, Ore. Ivey's job for the past two years included shooting rockets over cranes in preparation of a telemetry study focusing on Pacific Flyway populations.
His lecture at this year's Othello Sandhill Crane Festival will be a highlight of the event.
Fired from an elevated platform, the rockets carry a 40-foot by 60-foot net to capture cranes who were lured to the target site with kernels of corn, Ivey explained.
"Setting the rockets off is one big boom that flushes everything within a quarter mile," he remarked.
The captured birds were outfitted with satellite transmitters that activated once a week in winter and summer, twice a week during crane migrations.
"The GPS location data were downloaded to a computer and opened in Google Earth to display each crane's movements," Ivey noted.
Two years of data files give us a pretty good picture of the biological importance of Othello.
"Of the staging areas on their 2,400 mile migration from California to Alaska, Othello is the most important site. It's their primary spring and fall staging site," he said.
"Staging" is the term for migration stop-overs, when cranes rest and bulk up on feed that's mostly agricultural residue. Much of their travel they do by long-distance soaring on high altitude air currents, Ivey said.
"They get up to those thermals, some of them higher than a half-mile, by circling upward. 'Kettling' is the term for that. They don't always find a high-altitude current; sometimes they'll try four or five times before they find one that's going in the right direction," he said.
The cranes attracted to Othello are the Lesser Sandhills, standing four feet tall, their wing span about seven feet.
The Greater Sandhill cranes are a less common subspecies; even though they're slightly larger birds they fly smaller distance to nest in Oregon, Washington, and British Columbia, and their daily travel from roosting to feeding sites averages only 2 kilometers one-way, compared to the Lessers' average of 5 kilometers.
A third Sandhill crane is now thought to be a hybrid subspecies, Ivey said.
"The Canadian Sandhill cranes mostly migrate up to the forests in Canada. Genetic studies indicate that after the ice age when the Greater and Lesser Sandhills were mostly separated, some of them inter-bred," he said.
In terms of evolution, cranes rank the most ancient birds together with the grebes and loons.
"The oldest crane fossils are dated 37 million to 54 million years," Ivey said of the crane species' origin. "The first cranes that looked a lot like the Sandhill cranes today go back about 9 million years. That's the date of a fossil found in Nebraska."
A sad time for cranes was in the days of "market hunts" in America.
"Market hunting goes back to the Hudson Bay days. They actually had trumpeter swans hunted for their skins. They were used for cosmetic products," Ivey said. "Sandhill cranes were hunted extensively for their meat. In San Francisco in 1853, cranes sold for $18 to $20 apiece to replace the Christmas turkey."
By the 1930s, market hunts had reduced Greater Sandhill crane numbers so much that by 1941 they'd become extinct as a breeder in Washington. Because of that, all Sandhill cranes were declared an endangered species in the state in 1981, Ivey said. The Greater Sandhills have made a modest comeback since then, a few pairs once again nesting in Washington, near Mt. Adams.
Of the Lessers, the Pacific Flyway population is estimated at 30,000 to 50,000, with about 75 percent of them reliably enjoying Othello's irrigated agriculture each spring and fall.
As for Othello's annual crane festival, it's become Washington's premier nature festival.
"The festival is an opportunity to learn about the cranes' great role as an umbrella species," Ivey put it. "The habitat that cranes like for their staging sites benefits other western species as well, killdeers, meadow larks, curlews, golden plovers, and others."
Data from Ivey's telemetry study will be used in bird habitat conservation strategies. In some regions such as the crane wintering grounds of California, farm crop compatibility is an issue, he noted.
"When farmland goes from alfalfa and row crops to turf farms, orchards and vineyards, that cuts into the feed supply for cranes," he said.
Crane migration information will be used in the environmental analysis of a planned wind farm near Othello, Ivey said.
On a personal note, he related that the study of bird life is exactly what he'd wanted to do professionally. For 15 years he was a biologist at Malheur National Wildlife Refuge in Oregon - also a major stop-over for cranes - and currently he's working on his PhD at Oregon State University in Corvallis.
"Getting my PhD is a personal goal. My dissertation will be ready this summer," he said.
With his professor 15 years his junior, Ivey's doctoral tack is more of a theoretical abstract than his biologist freelance work, although that's what he enjoys most, "the practical application of science ... Birds are my passion."