Blending in

Some animals that live in snowy places are masters of hide-and-seek. Unlike the popular children’s game, however, the stakes in this version of hide-and-seek are life or death. Blending in with the environment makes an animal harder for a predator to see.

Camouflage is an adaptation that allows an animal to hide in plain sight by changing its appearance to match its surroundings. In many northern places, the landscape is a combination of brown, green, and gray in the summertime, whereas the snow-covered winter landscape is white. Over time, animals inhabiting snowy places, such as the snowshoe hare, ermine, and Ptarmigan (Willow, Rock, and White-tailed) have evolved to turn white in the winter and brown-ish in the summer.

Ptarmigan, snowshoe hares, and ermine are are important  sources of food for predators such as  lynx, foxes, and predatory birds. The ability to blend in with their winter and summer environments helps them to avoid being detected and eaten by predators, allowing more of them to survive and produce young.

Which of these animals can you find in the winter and summer photos below?

Photo by Kalabaha1969 on Wikimedia Commons (CC BY 1.0)
NPS Photo / Jacob Frank (Public Domain)

Double duty

The ermine is the only North American weasel that turns white in the winter. Wildlife biologists think that its black tail acts like a “decoy” that predators such as owls aim for. If an ermine loses a tail, it can survive, but if a predator attacks its head or body directly, it can’t.

a white and brown bird blending in against snow and branches
NPS Photo / Robbie Hannawacker (Public Domain)
NPS Photo (Public Domain)

Can you find the bird in each picture?

The Willow Ptarmigan is a master of camouflage. Here, it blends in with the tundra in Denali National Park and Preserve in Alaska.

white snowshoe hare in white snow
NPS Photo (Public Domain)
NPS Trail Camera Photo (Public Domain)

How many hares?

The snowshoe hare (related to rabbits, but not the same type of animal) is one of the most well-known examples of camouflage, not just in winter, but also in summer. How many hares do you see in the trail camera photo?

Adaptation through evolution

This snowshoe hare still has its white winter coat, but the snow has already melted. The timing of changes in coat colors has evolved over millions of years. Changes in snow patterns will affect their survival. NPS Photo (Public Domain)

These animals aren’t able to choose to change color based on when there is snow on the ground and when there isn’t, however. How do they know when to turn from brown to white and back again? Hormones in their bodies respond to changes in day length by causing their fur and feathers to change colors (growing new fur/feathers or in the case of the hare, changing color of hair tips to white) in the fall and spring. In years when snow doesn’t cover the ground until later than usual, these animals are easy to see when they are white while the environment is still brown. Likewise, when snow persists late into the spring, they might already be changing to their summer coats, standing out against the still white background. Animals that avoid predation survive to produce young with similar traits, and over time, adaptations like camouflage become more common.