April 20, 2019

Caribou herd demonstrates some `instinctive behavior’

ORONO — Caribou roaming through northern Maine’s wooded laboratory are exhibiting some interesting and instinctive behavior, although two more members of the herd have died, said Maine Caribou Project leader Mark McCollough on Thursday.

Twenty caribou bred in captivity in Orono were released northeast of Baxter State Park in April. Three adults have died since then, one in May and the other two more recently. One calf is alive and well, and project leaders suspect others may be in remote areas.

On Wednesday, researchers flew to locate the caribou and discovered all but one are in about a 10-mile radius of the release site.

Researchers transplanted the animals from Newfoundland in an effort to restore Maine’s natural history. The caribou was last seen in this state in 1908.

“Our goal is to establish a self-sustaining herd of caribou in the wild where enough individuals are able to find each other in the fall and have calves the next spring to offset any that had died the year before,” said McCollough.

He said many of the cows are wandering from the release site, which is normal. Mating season is in October, and cows are known to travel great distances from the herd’s central location to have their calves.

“Once they have their calves they return to a central area. We’re starting to see that now, and that’s very encouraging,” McCollough said. “They seem to be able to find each other quite well.”

Sometimes they will travel 15 miles to meet up with other caribou, he added.

During the mating season, herds could be as large as seven and are led by a stag who will do the breeding. In Newfoundland, a stag could gather a harem with as many as 80 cows, McCollough said.

Though the behavior is encouraging, it is also dangerous. October is hunting season. In addition, caribou in large numbers could be easy prey for black bears or wolves.

Speaking about the two caribou that died recently, McCollough said the cow’s death could not be determined, but she probably fell to bear predation. The other, a stag, got mired in a bog hole and drowned. He said these deaths are common among other Maine wildlife, such as moose and deer.

But on the other hand, McCollough said, “We’ve had at least one calf born that’s radio collared and still doing fine.” He said no other calves have been found, but there are several cows in remote areas that researchers have been unable to get to, and he suspects those females may be nursing or getting ready to give birth.

He said some calves died shortly after birth and others were victims of hungry bears.

“In Newfoundland, about 75 to 80 percent of the calves die during their first year of life, so the mortality in calves is to be expected.” About 30 percent of the calves fall to bear predation, McCollough said.

“It’s only when you do these very intensive studies to find out what happens to these young animals, to be there virtually as they’re born and find out some of the things we found about bear predation.”

If the project goes well, 25 caribou will be brought directly from Newfoundland in late fall or early winter and released in the northern woods to join relatives already in the wild. That herd, McCollough said, would be mostly pregnant cows.

Ultimately he wants to see a Maine caribou population of 100.

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