7 Animals That Turns White In Winter

Animals employ various strategies to cope with winter’s challenges. While some hibernate or tirelessly forage for food, others grow dense winter fur for warmth.

Interestingly, certain species adapt further by changing their coat colors, enhancing their hunting prowess or camouflage as prey.

Contrasting with year-round white animals like polar bears and snowy owls, these remarkable creatures dynamically alter their appearance with the changing seasons, showcasing nature’s incredible adaptability.

What Causes Animals to Turn White in Winter?

Hair turns white due to a lack of pigment. In animals, melanin cells create hair color: eumelanin for black/brown and phaeomelanin for red/yellow. Albinos lack melanin, hence their white appearance. In the fall, when animals grow white coats, their bodies stop producing melanin, leading to colorless fur.

Daylight length, not cold, drive seasonal fur changes. Animals sense daylight changes, triggering hormone release and new fur growth. In labs, changing light exposure can simulate these natural cycles.

Animals that Turn White in Winter

Let’s discover the extraordinary animals that transform into winter white to thrive in the snowy season.

1. Arctic Fox

Arctic foxes exhibit a fascinating color change, shifting from brownish-gray in summer to frosty white in winter. Interestingly, those in coastal areas of Alaska and Canada maintain a slate gray color that only slightly lightens during winter.

These foxes display various color phases; some in the extreme northern regions, where snow cover and ice are permanent, stay white all year. In contrast, others transition from summer brown to winter white. This adaptive trait is similar to that of snowshoe hares found from the Pacific Northwest to Alaska.

A significant threat to Arctic foxes comes from their relative, the red fox. Historically, their territories barely overlapped, but climate change has allowed the red fox to encroach further into the Arctic fox’s territory, intensifying competition for food and even leading to predation.

2. Snowshoe Hare

In the far north, snowshoe hares adapt to their environment by changing their coats from brown in summer to white in autumn. This color change is believed to be linked to photoperiod or daily light duration.

As days grow shorter, signals from the retina prompt the hare’s brain to initiate the shift from brown to white fur, starting at the extremities.

A recent study analyzing 44 years of data on snowshoe hares in Canada’s Yukon Territory found that warming temperatures are causing hares to delay their transition to white. This delay could impact their camouflage abilities and survival in a changing climate.

3. Ermine (Stoat)

In certain mountainous regions with prolonged snowfall, some stoats have the unique ability to turn white. This rapid transformation, often completed in a week or less, is known as a ‘catastrophic molt.’

The purpose of this white coat, or ermine, is to blend in with snowy landscapes for camouflage. Their uniquely patterned fur (ermine) was once used to trim the robes of royalty and clergy.

However, due to climate change, these now white stoats often find themselves starkly visible against increasingly less snowy backgrounds that remain brown and green, highlighting the impact of changing climates on animal adaptations.

4. Ptarmigan

The ptarmigan stands out among birds for its unique adaptation of molting into snow-white feathers for half the year. The three species – rock, willow, and white-tailed ptarmigans – are exceptionally suited for surviving harsh winter conditions in northern regions and high altitudes.

The white-tailed ptarmigan becomes completely white, whereas the willow and rock ptarmigan keep some black feathers in their tails. These birds also develop ‘white boots’ or downy foot coverings, aiding them in walking on snow.

Their winter feathers contain air bubbles, which not only provide insulation but also scatter light, giving them a brighter white appearance than other white birds.

5. Weasel

As winter nears, many weasels transition from brown summer fur to a nearly pure-white winter coat, a crucial adaptation for these animals who are both hunters and hunted.

Among the weasels undergoing this change are the least weasel, the long-tailed weasel, and the short-tailed weasel, or stoat, as discussed above. Weasels living in southern regions typically retain their brown fur year-round, unlike their northern counterparts.

In areas with mixed climates, some weasels may have an incomplete color change, resulting in a patchwork of white and brown fur. Intriguingly, studies show that these color changes in weasels occur regardless of temperature or location,

6. Siberian Hamsters

The Siberian hamster, also known as the Dzhungarian hamster and commonly sold as the “winter white,” is unique among the animals on this list as it can be kept as a pet.

This hamster variety shifts from a silvery chinchilla color to mostly white when exposed to natural light in its environment, regardless of temperature changes.

7. Collared Lemmings

The collared lemming is unique as the only rodent that turns white in winter. These voles, resembling mice but adapted for northern environments, have short tails, rounded faces, and long fur that almost conceals their small ears.

They remain active in winter, feeding, and tunneling under the snow while evading predators like snowy owls and foxes. In summer, their fur is gray with buff to reddish-brown hues, marked with dark lines on the back and head sides. In winter, their coat turns completely white.

Interestingly, they mostly burrow under the snow, which seems to make their white camouflage less necessary. Historically, their skins were used by Eskimo peoples as decorative elements in clothing.

The Evolutionary Significance of Winter Camouflage

An interesting theory posits that animals with pale coats have better insulation. The absence of melanin, the pigment that colors hair in white fur, creates more air spaces within the hair shaft, enhancing insulation.

This adaptation serves dual purposes for mammals that turn white: it offers camouflage and additional warmth. The colorless white fur, with its increased air capacity, functions similarly to a winter coat, providing essential warmth.

Therefore, the evolution to white fur might be a strategic response for both concealment and thermal regulation.

Conclusion

The remarkable transformation of various animals into white winter coats is a fascinating adaptation for survival in snowy environments. This change, often influenced by daylight rather than temperature, offers both camouflage and insulation, showcasing nature’s incredible ability to help creatures thrive in changing seasons and climates.