Okanagan's Nature Nut - a nature blog by Roseanne Van Ee - January 23rd, 2026

Okanagan's Nature Nut banner. A photo of Roseanne Van Ee in a circle frame on the left. The background images are a mix of different tones of green with a nature forest/mountain theme.

January 23rd, 2026

The Subnivean Wilderness

A whole new temporary ecosystem develops every winter wherever snow piles deeply enough to cover plants. It’s the subnivean (under snow) environment. High hills, subalpine mountain environments and northern BC reestablish subnivean worlds every November to April, and sometimes longer. In some places that’s half a year or more.

As snow falls and settles, it bends over grasses, shrubs and even young trees, and piles up on top creating a tunnelled network on the ground. The Earth is always giving off enough warmth to keep the ground air temperature above freezing. Imagine!; it could be -20C or colder outside, but remain a consistent +5C on the ground under the blanket of snow.

Mice and other small mammals live under this downy quilt of snow that shelters them from the cold above. The critters run around through their tunnelled habitat subsisting on lichens, seeds, fungi, plants, and some on stored food. Hawks can’t find the critters, so they migrate, but owls stay and listen. They can hear mice under half a metre of snow and dive down talons first to catch their prey. Coyotes can catch the scent of subnivean rodents. With a fierce pounce they dive into the snow muzzle first.

Snow weasels/ermine enter the subnivean network through holes beside shrubs and tree trunks to catch rodents. Spruce Grouse and Ptarmigans will dive into subnivean air pockets to keep warm, especially at night. By mid February the CO2 levels get high in these passageways and pockets, and the little critters come up and out occasionally for a breath of fresh air. Wouldn’t you know it; that’s just when male owls get busy supplying their ladies with food and furs.

Black Bears cozily hibernate under snow-covered fallen logs or against tree trunks with large, limber snow-covered branches that eventually close off the den once snow piles up.

Snowshoeing is a marvellous way to encounter this wild winter wonderland. Next time you’re out snowshoeing, see if you can identify the wildlife tracks. Look for subnivean world entry holes beside tree trunks or near bent over, snow-covered shrubs which look like bumps on the undulating snowy landscape. And realize there’s a whole busy community thriving under your trail.

If it’s warm enough, stay still for a few minutes. You may be lucky enough to catch some subnivean comings and goings. Bundle up and enjoy playing winter detective. Kids love this.