Roam and Reign – “Winter is Here” Caribou Edition
Here comes the king of the tundra. Being one of the few animals escaping the mass extinction of species after the last ice age, caribou are royally adapted to life in the North, which happens to be predominantly winter season! In the wild, they live all across the circumpolar region, including Europe and Russia, where they are called Reindeer. Both Caribou and Reindeer are the same species, only the Reindeer is generally a bit smaller and most herds on the Eurasian continent are actually domesticated. The Wildlife Preserve is home to a group of the Boreal Woodland Caribou, the largest representative of its kind.
Compared to their body size, Caribou have relatively large, split-hooves which they can spread the toes out wide. This enables them to distribute their weight onto a larger surface and walk across snow, ice and sort-of-frozen swamps more efficiently. Their hooves also harden up in the winter and become overgrown by hair. The hair insulates the live, fleshy inside part of the hoof from the cold and the hardened horn on the outside helps them to paw through the snow cover to get to their food.
Like most arctic animals, their posture is stocky and compact, in order not to lose too much body heat. A crucial addition to body shape is their coat. Like most dogs, caribou have a double coat with a softer underlayer and a coarse outer layer. This prevents heat loss but also from getting wet when they lie in the snow for example. Hairs of the outer coat are hollow, which offers further insulation.
Even their noses are designed for the cold – the inner bones are shaped to increase the surface area inside the nostrils so when they breathe in the cold air, it has more time to warm up within the body before reaching the lungs. And on the way out, the air is cooled down on the way and most of the body heat is retained before breathing it out. Have you ever noticed steam coming out of a caribou’s nostrils? Neither have we and that’s why.
Caribou and reindeer follow ancient migration routes throughout the seasons. Some just change a mountain range to get to their winter food supply and spring calving grounds, others travel over hundreds of miles to get to a different habitat. Their roaming is also believed to have evolved following environmental conditions. Compared to the storm-beaten, treeless tundra, the boreal taiga forest offers better shelter and easier access to food due to thinner snow cover.
In the wild, the Caribou’s main diet is an algae-like organism called lichen. It grows on rocks and on specific soil conditions such as the wide pine tree stands of the boreal forest. The animal reaches its food by pawing away the snow on top of it with their hooves or scratching it away with their antlers, sometimes even pushing through thin ice layers. As well adapted as caribou have become over millennia, the – in evolutionary terms – recent climate change poses entirely new challenges. Temperatures don’t always remain below freezing all winter. There are so-called warm spells, where snow on the ground melts and re-freezes as a thick, impenetrable layer of ice once temperatures drop again. This can – and has been – detrimental to the survival of the caribou. While their technique with hooves and antlers works well in the fluffy, powder-like snow that falls in dry northern climates, intermediate melting of the snow cover, increased humidity from lack of sea ice and in some cases even freezing rain – make it impossible for caribou to punch through the thick layer of ice in order to get to their food. In 2016, tens of thousands of reindeer died of starvation during exceptional weather conditions.
Caribou at the Preserve fare quite well even in those exceptional weather conditions. Staff monitor and feed animals daily. In the summer the individuals are able to bulk-up on plenty of high nutrient foods. It’s important that wild caribou populations have good summer food sources to consume for both the success of their offspring and ultimately their species! Protecting these special places so caribou can thrive has been an on-going effort in the territory and beyond. In the territory and specific to woodland caribou the rebounding Southern Lakes Caribou sub-population has been a long but successful story by many . We have been able to expand our learning and understanding to these animals’ needs, movements and adaptations in a ever changing world.
As a wilderness guide, Sarah has spent many days out in the bush over the years. Sitting out there glued to the scope is just as fascinating to her as observing and following animal tracks in the depth of winter, trying to draw conclusions of what this particular critter might have been up to. Sarah is passionately sharing her stories as part of our team of wildlife interpreters.