Gimme Shelter

Photo Credit: Norma Kerby

Gimme Shelter

👤Norma Kerby 🕔Nov 25, 2016

The tracks in the deep snow tell a grim story: the moose sought shelter under young hemlocks. With its back to the conifers, it faced out into the clearcut and didn’t see the lone wolf come through the small trees. It attacked from behind, chasing the moose into a jumble of buried logs and down into a draw. The rest of the pack descended from the banks above. A catastrophe of tracks disappears along the gulley and across the open area as far as we can see.

For my Northwest Community College ecology class, this set of tracks clearly illustrates the difficulties faced by moose in winter. Fleeing across the clearcut, the moose broke into the snow crust, stumbling over the hidden, fallen logs as it travelled through deep snow. Its pursuers, much lighter and smaller, ran along the top of the snow in a faster and more energy-efficient  fashion. The fate of the luckless moose is apparent.

The results of our class project, which surveyed moose habitat patterns in a proposed subdivision area, matched other research examining moose winter ecology. By comparing the moose-wolf interactions within this uninhabited young forest to moose behaviour in an established neighbouring rural subdivision, it becomes apparent that, surprisingly, property owners in rural areas can become important factors in winter moose survival.

The first pattern to emerge is that overwintering moose, especially cows and calves, are using rural developments as deterrents to wolf attacks. By moving close to housing, the moose appear less likely to have the local wolf pack attack them. Except for encounters with dogs and the occasional irate fruit-tree owner, they are able to forage and shelter close to buildings without negative effects to either themselves or the property owners. Often, the rural residents are unaware that they have moose living on their land.

There appear to be several factors key for successful winter moose habitat in rural residential areas. The most important is public safety. Property owners must be willing to share winter space with moose. There has to be sufficient land and the property must be properly configured to minimize human-moose-dog interactions.  According to interviews with residents, dog personalities were an important factor. Some dogs ignore moose while others become obsessed with harassing an animal that outsizes them 10 or more times. According to our study, moose primarily use properties where harassment and dog packs are not a factor.

The winter elements

Other important factors are the provision of cover and shelter from deep snow and cold winds, plus the availability of food.

Moose are masters of disguise. With their dark colour and long legs, they easily blend into the forest. Even a patch of conifer trees 10 cm in diameter or greater provides concealment. Conifers intercept snow, lowering its depth. Their thick needles break the wind, providing thermal shelter. Over 90 percent of moose tracks around conifer patches were on the south side of the block, where the conifers had blocked the cold north winds and the moose could warm themselves in the low intensity winter sunlight.

According to Smithers wildlife consultant Laurence Turney, privately owned rural properties can be important moose habitat: “The ideal is a patch of trees about 20 metres by 20 metres, with trees old enough that the canopies touch each other for snow capture and the prevailing wind is blocked. On my property, I trim the lower branches on the downwind side so the moose can get under the trees. Even three to five conifers together can be enough to form a shelter. Talk to your neighbour. A cluster of trees along a property line can become valuable thermal shelter for moose and other wildlife.”

Another supporter of moose habitat on private land, Terry Houghton of Fort St. James, lives in a moose-overwintering zone along the south shore of Stuart Lake. Houghton, a former high school science teacher and active trapper, manages the shrubs on his property for the moose to eat.

“I have had as many as five moose stay here for the winter,” he says. “Moose need to be able to access valley-bottom areas to avoid the deep snow higher up in the hills and mountains. On my property, I don’t want to clear all of the land. The wildlife has to have shelter. I like to see the moose. I pay the taxes on this property, but it doesn’t just belong to me. I have foxes that pass through, the deer and birds are here, and in the winter I have moose.”

According to Houghton, keeping shrubs and trees from over-maturing by pruning the lead branches allows each summer’s new growth to provide first-class moose forage. The best species in the northern interior to give good winter nutrition for moose are red osier dogwood, willow, young poplars, elderberry and, unfortunately, his raspberry patch.

The human element

As most of northern BC’s valley bottoms have been modified by human activities, property owners can become important factors in the survival of winter wildlife populations. Normally, a large, healthy adult moose like the one in our study would have stood its ground, striking out its front feet with deadly kicks that could cave in the skull of any wolf that came too close. Why did it choose to run?

In ideal moose habitat, the conifer grove in which the moose hid itself would have had larger trees. Backed up against a big tree, its hindquarters would have been protected. Its powerful kicks forward would have kept its predators at bay. But in this area, there were no groves of large-diameter timber. Everything was logged and only a few decades into regeneration. Attracted by the deciduous regrowth in the logging setting, the moose had food, but the lack of older trees left it vulnerable to harsh weather and exposure to predators attacking from behind.

From the blood on the snow, somewhere in the tangle of regrowth masking the steep-walled gulleys stretching ahead, the fleeing moose most likely became food for a web of predators and scavengers in a harsh winter environment. If only that moose had chosen instead to winter in a rural property a kilometre to the north. The property owner there, a fan of wildlife sightings, has left a grove of old hemlock and cedar trees as wildlife habitat, perfect for sheltering everything from a vole to a large ungulate trying to avoid predation.