Fairbanks biologists track sandhill cranes via satellite

Posted: Thursday, April 11, 2002

FAIRBANKS, Alaska (AP) -- Once a week, Jason Caikoski sits down at his computer and tracks down his four sandhill cranes.

''These are all data points,'' Caikoski said, pointing to a series of 11 dots on a map of North America displayed on a computer screen.

The dots -- 10 black and one purple -- resembled something you would see in a connect-the-dots book, running in a diagonal line from Alaska, down through the prairies of western Canada, into the U.S. Midwest before stopping in Texas.

The dots serve as a sort of flight plan for 19427, one of four sandhill cranes that biologists with the Alaska Department of Fish and Game captured at Creamer's Field Migratory Waterfowl Refuge in Fairbanks last August and outfitted with satellite transmitters.

The battery-powered transmitters, which were strapped to the birds' legs and have a life span of 18 months, have allowed biologists to track the cranes during their migration south, and now back north, without leaving their desks.

''What satellite telemetry has done is allow us to collect data without being where the birds are,'' Caikoski said. ''It's allowed us to collect data on animals that move long distances.''

Using longitude and latitude coordinates provided by the satellite transmitters, which come on for one six-hour period every four days, Caikoski has been able to plot the courses of the four cranes from Fairbanks to Canada to Texas and now back to Nebraska.

Almost eight months after being wired for satellite, all four cranes are alive and flapping on the Platte River in Nebraska, their first stop on the 2,000-plus mile flight back to their nesting grounds in Alaska. The first sandhill cranes typically touch down in the Tanana Valley in mid to late April.

The fact that the four birds from Fairbanks are on the Platte River is no surprise to biologists.

''We were 90 percent sure they were going to go to the Platte River,'' Caikoski said.

That's because some 500,000 sandhill cranes, about 80 percent of the world's sandhill crane population, flock to the Platte River each spring before moving on to their respective nesting areas.

What biologists don't know, however, is where the birds will go when they reach Alaska. They might head to the Yukon-Kuskokwim Delta or the Seward Peninsula, two popular breeding grounds for Alaska cranes. They could fly across the Bering Sea to Russia, where there is a known breeding population of cranes. They may even head north to the Yukon Flats.

Chances are, though, they will nest somewhere in the Tanana Valley, probably in the Tanana Flats south of Fairbanks.

''If those birds are coming (to Creamer's Field) in mid to late August it's most likely they aren't part of the big nest populations out west,'' said biologist John Wright, manager of Creamer's Field Migratory Waterfowl Refuge. ''I'd be very surprised.''

Most of the birds that come from the Yukon-Kuskokwim Delta, the Seward Peninsula and Russia migrate through the north side of the Alaska Range, not the Tanana Valley, Wright said.

All the information biologists are obtaining about the cranes' migration routes, however, is superfluous.

The real purpose of the Fairbanks project is to track the cranes when they congregate in the Tanana Valley for the fall migration during August and September. Each fall, some 2,000 or more cranes use Creamer's Field as a staging area before embarking on their flight south for the winter.

The barley fields at Creamer's Field are used as a magnet to attract waterfowl such as sandhill cranes and Canada geese away from air traffic at Fairbanks International Airport, Eielson Air Force Base and Fort Wainwright, where the birds pose a threat to incoming and outgoing aircraft. Biologists want to figure out where the birds roost at night in relation to area flight paths.

The $12,000 project is being funded by the state, U.S. Army and Fairbanks International Airport, Wright said.

While the migration route of the cranes may not be important to the overall goal of the project, it is impressive nonetheless.

Consider that 19247 made the 1,700-mile flight from Fairbanks to Saskatoon, Saskatchewan in about three days.

''That's in a straight line,'' Caikoski noted. ''They're probably flying over 2,000 miles.''

After resting more than a month on the prairies near Saskatoon, the bird made the 1,400-mile trip from Saskatoon to Texas in only two days.

Based on the data he has received, Caikoski calculated that the birds average 50 to 55 mph when they're flying.

''Their strategy seems to be to fly long distances and stop at a favorable location and then make another long stint,'' he said. ''They basically flew from Fairbanks to Saskatoon in one stint.''

The cranes spent much of their winter, basically from October to March, bouncing around in west Texas. All four birds moved separately up to Nebraska within the last few weeks.

''They're not traveling together as a group,'' Caikoski said.

Now all biologists can do is wait until the cranes continue north, which they should do any day now. Because all four cranes outfitted with transmitters are adult males, biologists don't know if they will stop at Creamer's Field this spring or fly directly to their breeding grounds, wherever they may be. The fact all four cranes are still alive is a good sign.

''So far we're lucky,'' said Wright. ''They're all still kicking -- the birds and the batteries.''


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