Falling snow creates a white world, softening the landscape and hushing loud sounds. Snow benefits the active lifestyles of wildlife that hasn’t migrated south and isn’t hibernating.
Snow is an efficient insulator of the ground and is welcomed by some animals adapting to survive. Cold, dry snow consists of millions of snow crystals separated by tiny air pockets. When snow accumulates 6 inches or more and is not very wet, the snow insulates enough to protect ground-level life from extreme temperature fluctuations. Radiant heat from the earth gets trapped, slightly thawing the ground, while making trickles of water appear from the bottom of the snowpack. This space between ground surface and snow is called the subnivean zone, and the temperature there stabilizes around 32° F.
The sun’s radiation melts snow next to tree trunks or rocks, creating soft spots for mammals to move around and tunnel under the snow. Living in the subnivean zone, meadow voles and white-footed mice find leftover seeds, insect eggs, and bark to chew on. Bent-down grass clumps make good nests for sleeping. If the snow blanket gets compacted above them, they create vent holes to let excess carbon dioxide escape.
Long-tailed weasels change their fur color from light brown in summer to white in winter, but they retain the black tips of their tails. This camouflage coat, along with a long, slender body, helps these stealthy predators sneak up on tunneling rodents, chasing after and quickly subduing their prey. Weasels need to eat often to sustain a high metabolism. With little fat to tide them over between meals and a thin fur coat, they also utilize burrows to rest and escape the cold.
Like wearing snowshoes, a ruffed grouse grows combs on the sides of its toes for better traction. After feeding on tree buds, the grouse dives into powdery snow by tucking in its wings just before entry to make a den that is up to 2 feet long. This game bird hides from hawks while roosting and digesting the food. Grouse stay in a snow den for many hours at a time during both night and day, using several dens throughout winter.
Look for holes leading under a snow blanket on your next outdoor adventure!
Created in clouds. Snowflakes are created in clouds when ice condenses directly from water vapor in the air onto a speck of dust. Water molecules arrange themselves in an ordered pattern as they attach to the growing ice crystal.
Forming crystals. Crystals form when temperatures drop below 32° F and humidity rises above 100 percent with excess water vapor. Thin hexagonal plates grow with flat surfaces called facets. Sunlight reflects off these mirrors, making snow sparkle.
Prisms and more. When temperatures decrease from 25° F to 15° F and air becomes supersaturated, snow forms into solid prisms, hollow columns, and long needles.
Supersaturation. Spectacular solid plates, sectored plates, and intricate dendrites develop when the air drops between 15° F to -5° F and becomes more supersaturated. The greatest variety of designs occurs in these conditions.
Simple or complex. At temperatures colder than -5° F, smaller plates and columns will form. Complex crystals appear when humidity is high. Simpler faceted crystals form when humidity levels are low.
Crash course. After falling from the cloud, snowflakes stop growing and damage occurs from midair collisions, resulting in asymmetrical crystals. This is why it is said “no two snowflakes are alike.” Snow gradually evaporates in a process called sublimation.
Watching snowflakes. For snowflake watching, all you need is a pocket-sized hand lens to look at flakes falling onto your mitten!