Biologists prepare for caribou census

Posted: Friday, June 16, 2000

The caribou of the central Kenai Peninsula are cuter than moose and increasingly visible.

The animals people are most likely to see all belong to a single group called the Kenai Lowland herd, and they are intriguing biologists almost as much as they delight wildlife watchers.

Ted Spraker, the area wildlife biologist for the Alaska Department of Fish and Game, calls them mysterious.

One of their most puzzling and dramatic activities takes place this time of year, when they gather in huge groups -- for no apparent reason.

About 100 caribou cows and calves will come together within the next few days. The site of the annual gathering is unpredictable, but it usually takes place in the area of Marathon Road north of Kenai or the Kenai River flats near Bridge Access Road, he said.

After a few days, they will drift apart.

Spraker has seen as many as 16,000 animals crowded together in other parts of the state. Why they gather is unclear, but people have speculated it may have something to do with defending calves from predators or avoiding biting insects, he said.

"We call that the post-calving aggregation. That is when I can count them," he said.

Spraker's aerial surveys are part of a concerted effort to monitor peninsula caribou, especially the Kenai Lowland herd. Unlike other herds biologists reintroduced to the peninsula in the 1960s and 1980s (See related story, Outdoors, page C-1), the central peninsula group has struggled to grow.

Last year, he counted 140 in herd.

"This lowland herd has had a tough time," he said.

Spraker attributes the problems to predation. The herd produces many calves, but few of those survive long.

Coyotes, wolves, lynx, bears and even eagles prey on the calves in the wild. Most caribou herds live in open areas such as tundra, where they can keep an eye out for enemies, but the lowland herd caribou spend much of their time in the forest.

"It just makes sense," Spraker said. "If you use your eyes to save your butt, and you live in the trees, something can sneak up on you."

Living closer to humans than most, the herd has other problems.

Domestic dogs are a significant predator on the calves (See related story, page A-1).

"We've had numerous cases over the years," he said.

Spraker urges people to keep Rover from roving, especially this time of year. The calves were born in May and remain vulnerable.

Cars are another big killer of Kenai caribou. In one case, a drunk killed five in a single incident, he said.

Despite their dangerous lives, the surviving adults are in prime condition. They tend to be larger than other Alaska caribou, and they calve earlier, which is a sign of good forage and mild winters, he said.

"The largest set of antlers ever recorded came from this herd," Spraker said.

The rack's measurements added up to 476 1/4 inches, and it is on display at the state Fish and Game headquarters in Anchorage. The official current world's record is 465 1/8 inches.

The Kenai antlers are ineligible for the Boone and Crockett record book, however, because they were shed, rather than taken in a hunt. Spraker knows exactly how big the mount would have been because he handled the bull during studies and measured its head, he said.

Unusual behavior also sets the herd apart.

It has changed since its beginning in 1966, when biologists released 29 head at Watson Lake near Sterling. The animals are fairly tolerant of humans and have shifted their ranges over time south and west, closer to developed areas.

The herd's original calving grounds were on the Moose River flats between Sterling and the Swanson River oil fields, and the animals wintered in the same area. They traveled back and forth to graze the area near Marathon Road and Beaver Creek.

But now they winter near the outlet of Skilak Lake and migrate in spring and fall along Funny River Road and through Soldotna and Kenai to calving grounds in the Marathon Road area and near the gas fields south of the northernmost loop of Kalifornsky Beach Road. That area, north of Kasilof, now hosts about 75 percent of the calving.

Spraker speculated that calf survival may be higher in the new locations.

The animals cross the Kenai River easily. When biologists used radio collars on calves to track their movements, they were surprised at their mobility.

"It seemed to me that the river was absolutely no problem to those newborn calves. And the adults swim like fish," Spraker said.

"I don't know why they've shifted. Changes in wildlife populations are usually pretty subtle."

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