• Submitted by: manso
• Society
• 05 / 26 / 2011

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Biologists learning where area raptors winter.This map shows the migration paths of three osprey captured and fitted with satellite backpacks in Grand Teton National Park last summer. Biologists say the Jackson Hole birds displayed some unexpected behaviors on their trips.

This osprey that was fitted satellite transmitter last summer has returned to Jackson Hole, giving researchers insight into its migration patterns. PRICE CHAMBERS / NEWS&GUIDE FILE

By Cory Hatch, Jackson Hole, Wyo.May 25, 2011. Two of three osprey fitted with satellite tracking devices in Grand Teton National Park last fall have returned after migrating thousands of miles to Mexico and Cuba, researchers said.

The three birds — two adult males and a juvenile female — were captured by Grand Teton and Craighead Beringia South biologists on Jackson Lake using a device called a “floating fish snare.”

The park’s senior wildlife biologist, Steve Cain, invented the trap.

The birds were then fitted with backpacks that use satellite technology to zero in on their locations.

A fourth bird, the mate of one of the males and the juvenile’s mother, was also captured but was killed — likely by an eagle — before migration began.

The juvenile female, the only captured bird that hasn’t returned, is still alive and well near San Antonio, Texas.

“That’s not unusual for first year birds,” Bedrosian said.

The juvenile’s father skirted down the Rocky Mountain Front, stopping for a month in Boulder, Colo., and then moved on to southern Mexico.

It’s the second male, however, that has researchers excited. That bird, which was not associated with a female or offspring, took several trips to the southern Wind River Range before he even started his migration. He then flew to Tulsa, Okla., for about a week, then to Florida and --on to Cuba.

The bird’s west-to-east and east-to-west movements are unusual, Bedrosian said. Migrating birds typically take one of four routes south: the Atlantic Flyway, the Mississippi Flyway, the Rocky Mountain Flyway (also called the Central Flyway), or the Pacific Flyway.

“This is one of the only instances that I know of where a raptor has gone from the Rocky Mountain Flyway to the Atlantic Flyway,” Bedrosian said.

Cain said, “We’re digging into the literature and visiting with colleagues to see if anyone has ever documented this kind of behavior.”

The bird’s repeated trips to the Winds also were interesting. “I don’t know why it would go down several times,” Bedrosian said. “It did it this spring as well.”

Aside from the oddities displayed by the lone male, the research is helping Cain and Bedrosian figure out the locations these birds rely on for rest and food during migration, as well as their wintering grounds. The juvenile’s father, for instance, was fishing in two distinct locations during its stopover in Boulder: Boulder Canyon and some wastewater treatment ponds.

“There hasn’t been any work done in the Rocky Mountain region with osprey migrations,” Bedrosian said. “At first, we’re trying to figure out how far and where they go and threats.”

The researchers also learned that the osprey returned about two weeks later than osprey in the southern part of the valley, “which makes perfect sense since there’s still ice on Jackson Lake,” Bedrosian said. “They can’t really fish yet.

“I was very concerned,” he said. “You never know what happens in rural areas with predators. We were all biting our nails, especially since they started their migration a lot later than we would have anticipated.”

The osprey research is part of a larger effort by the National Park Service to document and preserve migration paths of animals that spend only part of the year in the park, Cain said. From Grand Teton, pronghorn, mule deer, red-tailed hawks, harlequin ducks, elk, bison and moose migrate out of the park for part of the year. Other animals — wolverines, wolves, bears and cougars — have long-range dispersals out of the park.

“As various threats might end the migration of a given species, that species might not continue to exist in a national park unit,” Cain said. “That concern exists for many other species. The work that we’re doing here in Grand Teton has provided background information for what could be a national-level migration emphasis in the future.

“If we want to preserve the biodiversity of the park, we need to be looking beyond the borders and working with a variety of partners and stakeholders to preserve these migrations,” he said.

Bedrosian and Cain hope to capture at least three more osprey this summer.

Source: www.jhnewsandguide.com/article.php?art_id=7336