Peninsula caribou herds to be tracked by satellite

Posted: Monday, November 05, 2001

Biologists will have a better idea of the range different Kenai Peninsula caribou herds call home after fitting some with data logging devices linked to satellites.

During the fall caribou count, Alaska Department of Fish and Game and U.S. Fish and Wildlife Service researchers captured and tagged 20 adult female caribou in two herds.

The Kenai Peninsula is home to five distinct caribou herds; the Kenai Lowland, Kenai Mountain, Killey River, Fox River and Twin Lakes herds.

The cows that were tagged belonged to the Killey and Fox river herds.

Rick Ernst, a wildlife biologist pilot for the Kenai National Wildlife Refuge, said the collars some of the animals were fitted with include the traditional radio homing transmitters as well as newer "store onboard" Global Positioning System data collectors.

The devices receive GPS signals from orbiting satellites and record the animals' positions five times a day.

"We will get better information on their movement over the winter," Ernst said.

In the past, to locate an animal and log its location, researchers had to zero in on them from the air using the homing beacons. But given the shorter days and poorer weather of winter, it was more difficult to track them. With the GPS system, biologists only have to recapture the animals and retrieve the data.

"This is similar to what was done with the brown bear study, where we got a lot of data points," Ernst said.

The GPS collars cost $2,000 a piece. While more expensive than the simpler radio collars, Ernst said they are much more cost effective.

If the collars are left on for two years, at five data points a day, scientists can collect 3,650 locations that cow, and presumably her herd, have been.

Tracking the wanderings of the upriver herds -- which don't migrate like the Kenai Lowland and other herds in the state do -- is important to Ernst, who in May 2000 found cows calving on nunataks, peaks sticking up above the ice in the Harding Ice Field.

"I found it fascinating," he said. "They were miles from land."

He said it was likely the animals were on the nunataks to avoid predators.

"One of the reasons we used the store onboard collars is to get a lot better and more detailed information on where the caribou are moving," he said. "We want to know how much time they spend on the nunataks."

He said it was the first time caribou have been found in Kenai Fjords National Park.

While tagging the animals, Fish and Game wildlife biologist Ted Spraker said they made another interesting discovery. One of the adult cows in the Fox River Herd they captured had an ear tag, and after researching the number on it, found she had been a transplant to the peninsula in 1986, making her 16 1/2 years old.

"That's an old caribou," Spraker said. "But she was in excellent condition. She must have been the matriarch of the herd."

Spraker said the Fox River Herd is smaller than it has been in the past. He counted 66 animals and only four calves. He expected 80.

He said only one of the four calves was as large as calves from the Killey River Herd, at 130 pounds. He said the range of the Fox River Herd could be near its capacity to support the herd.

The Fox River Herd live primarily near the headwaters of Clear and Crystal creeks between the Fox River and Tustumena Glacier.

The Killey River Herd also was low on calves, he said. They had planned on collaring 19 calves, but only found 13.

"That's an indication that the Killey River may be exceeding it's carrying capacity," Spraker said.

The calves which were captured and collared this fall will be recaptured in the spring and weighed again. Ernst said the health of the winter range will be reflected in the health of the calves.

"If they weight the same, then their winter range is marginal or fair. If they gain, it's a little better, but if they lose weight, then it's poor," Spraker said.

The herd's population is currently 643, but should be 450, he said. The herd's homeland is on a bench between the Killey River and Tustumena Glacier, in the upriver areas around Funny River, Bear, Moose and Indian creeks.

He said there was a fall hunt designed to thin the herd, but only 39 cows were taken. The department had hoped to see 150 or more taken. The registration permit hunt had a bag limit of three cows each, and there was no drawing or lottery to participate.

The Kenai Lowland Herd migrates between the Kenai and Kasilof rivers in the summer as far north as Hope in the winter. It remains steady just under 150 animals. A June count found 131 animals, Spraker said, while a year ago, there were 140.

"They're hanging on, but not doing too well," Spraker said.

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