13 October 2017

Caribou comeback: Can the species ever return to N.B.?

Botanist doesn't hold out hope after overhunting and a parasite wiped out species out

By Shane Fowler, CBC News

When the leaves in the forests of New Brunswick change their colours, it signals to thousands of hunters to head into the woods in search of this provinces "big three" — moose, black bear, and whitetail deer.

But the nearly century old absence of a fourth big game animal, the woodland caribou, has had some hunting groups question if the native animal could ever be reintroduced in the province.
"They were here, as far as we know, since the glaciers left," said Gerry Parker, a former officer with the Canadian Wildlife Service who studied caribou in the Canadian Arctic. "They were here thousands of years."

"But the caribou were overhunted, mainly for their antlers," said Parker, who has written several books on early hunting and forestry in N.B. "People loved to hunt for those antlers."

In the province's early days those highly prized racks drew hunters north by the trainload coming from Boston and New York.

"In the 1880s word got out to the Americans that there was big game to hunt north of the border," said Parker.
Game shows and magazines promoted caribou hunting to a growing middle class that, while not able to afford big game hunting in Africa, could afford a day's travel to New Brunswick to trophy hunt caribou along with moose and bear.

Unregulated hunt

A map published in 1899 by New York Field and Stream Publishing Co. carved N.B. into a series of hunting grounds labelled as "Excellent Caribou Country, Excellent Caribou Ground, and Fair Moose & Caribou Ground."

But unregulated hunting would mark the decline of the caribou's reign. A photo from the New Brunswick Provincial Archives is marked with a note that states "last caribou shot in NB." It shows hunter Issaac Erd standing over a large slain buck and is dated between 1906-1912.

Following that final woodland caribou harvest a complete ban was placed on hunting caribou in N.B.

But it would prove too little, too late. According to Parker's research the last wild caribou sighting recorded in the province would be in the early 1930s.
But despite the devasting impact of overhunting on caribou there was another, unassuming, culprit that ensured that caribou would never return to New Brunswick.

"In the early 1800s the lumbermen went into the woods of New Brunswick once, maybe twice over, opening up the forests," said Parker. "That created grazing for deer."  

Lethal parasite

That coupled with the almost fanatical slaughter of wolves in the province by farmers and hunter alike allowed for whitetail deer to push north. Along with them came a deadly parasite that would prove lethal to the remaining caribou herd.

"There is pretty strong evidence that this is one of the factors that led to the precipitous decline of the caribou," said Stephen Clayden, a botanist at the New Brunswick museum. "A meningeal worm, it's a parasitic nematode, or commonly called a brain worm."

"It is carried by whitetail deer," said Clayden. "But is not lethal to them like it is to caribou."
Clayden has written about the decline caribou population in an article published in 2000 titled "The Last New Brunswick Caribou?"

"There were some really interesting observations by a guide and outfitter by the name of Bert Moore," said Clayden. "He wrote about his observations from his perspective in the late 1920s about caribou and deer in north-central New Brunswick."

"The last caribou he saw, in November 1928, was "walking in circles," wrote Clayden. "It was not until the early 1960s that this parasite, a tiny roundworm with the formidable name Parelaphostrongylus tenuis, was first shown to be the cause of "moose sickness." Further studies soon determined that its effects on caribou were similar to those in moose, but more severe and quick to develop."

"They can walk in circles for days," said Claydon. "If they get into water they can swim in circles until they drown."

"And there is strong circumstantial evidence that it was the interaction between deer and caribou that was one of the key factors that led to the disappearance of caribou from New Brunswick."

But the decline of the whitetail deer in northern N.B. has some questioning if that could provide the chance for a successful reintroduction of the caribou in this province despite the failed attempts in others.

For decades the deer season has been cancelled in most northern parts of the province, some since 1993, due to extremely low deer numbers according to the Department of Energy, Mines, and Resource Development. Some zones  have only had a season reinstated recently, albiet in a limited capacity.

Caribou comeback?

Reintroduction of caribou has worked, and failed, in other province. Quebec and Newfoundland and Labrador have seen partial success in their attempts to bring back the species. But Nova Scotia failed in their attempt in 1960s. Maine has tried to bring back the caribou twice, first in 1963 and again in 1990, to no avail.

But standing underneath several caribou mounts, displayed heads from hunts over a century ago at the New Brunswick museum archives, Clayden doubts that New Brunswick's current forestry practices would allow for caribou to survive, let alone thrive in the province.

"We know that if we look at other populations that their feeding in lichen rich habitats," said Clayden. "We still have some of those, such as areas with coastal bogs, like Miscou Island, that are rich in ground lichens that caribou would have feed on, foraging them by digging down through the snow pack."

"But in the summer we find they tend to feed on tree lichens," said Clayden. "What some people call 'Old Man's Beard.'"

"But the changing nature of the forest, in large part through the conversion of older stand to younger age classes, there probably isn't the abundance of tree lichens that there would have been a century ago."

Today there are only two known caribou residing in the province; a juvenile female that was born in captivity at the Magnetic Hill Zoo in Moncton, along with her mother. Given the continued presence of whitetail deer coupled with current forestry practices Clayden believes captivity is most likely the only way for caribou to survive.

"It's conceivable I suppose that if there were no interaction between deer and caribou, if there was an experimental reintroduction maybe caribou could survive for awhile," said Clayden. "But if we're thinking about a period of not just a few years, or even a few decades it seems to me the odds are probably pretty slim."