Moose Are Invading Farm Fields

In southern Canada, the unusual visitors have created new problems for drivers and growers.
A bull moose with velvet antlers in Alberta, Canada. (Photo: Ron Erwin/Getty Images)
Jun 1, 2016· 1 MIN READ
Katharine Gammon has written for Nature, Wired, Discover, and Popular Science. A new mom, she lives in Santa Monica.

Moose in Canada bring to mind forests and snow. But in some parts of the country, the animals have started to expand out of their normal habitat—far away from predators in the forests—and into a new ecological role as potential agricultural pests.

Researchers at the University of Saskatchewan collared and tracked 40 adult female moose and recorded each moose’s location once per hour, every hour, for two years. Laying the locations over agricultural maps, they discovered that the animals frequently foraged in prairie farmland, munching their way through a variety of crops, from flax and peas to canola. Most of the females were pregnant, and the researchers observed offspring grazing on crops in the spring alongside their mothers.

The study, published last week in The Journal of Wildlife Management, gives more evidence for the need to conserve prairie pothole wetlands. The house-size swampy areas host an abundance of waterfowl and animals, but farmers often fill them in to move equipment around their plots of land.

This is the first study that tracks moose in farmlands, said Ryan Brook, a researcher at the University of Saskatchewan. Back in 2010, Brook and his wife were driving in the prairie and stopped to take a picture of a sign depicting a moose crossing. “I laughed about some idiot putting up a ‘moose crossing’ sign in the wide open prairie, but now I’m as shocked as anyone to find out where the moose are moving,” he said.

The researchers have set up a Facebook page, “Saskatchewan Farmland Moose Project,” where people can ask questions and post information.

RELATED: Climate Change Is Drawing Alaska's Moose Onto the Tundra

Juvenile moose face a tough battle for survival in the forests, where 50 to 80 percent fall victim to bear and wolf predation. There are far fewer threats in farmland prairie areas. Brook and his team observed a successful-pregnancy rate of 90 percent in the population they studied, which he called a sustainable population.

Moose that live large on prairie farmland are evading predators. But the habitat shift could threaten their survival in the long term, said Brook, because with the forest far away, they rely on the small pothole wetlands for shade and water on days with temperatures above 57 degrees. “In a changing world, that’s a risk,” he said, because as temperatures rise in coming decades, those small wetlands will likely dry up or get too small to be useful to moose.

Increasing the numbers of moose on the move between forests and farms may also increase risks to drivers. Even in areas with low moose populations, animal-vehicle collisions cause more than $1 million in damages each year, according to the Canadian Department of Environment and Conservation. Seventy percent of accidents happen between May and October, when the animals are bearing offspring and mating.

The overall picture for moose is mixed. In parts of the U.S. and areas of British Columbia, moose populations have collapsed. Moose in New Hampshire have declined 40 percent in the past three years, thanks partly to infestations of winter ticks, which are multiplying in the warming climate.