In this blog article, we’re heading into the north country to have a look at the caribou of Alaska and Canada. Caribou are often referred to as reindeer in many countries…especially those of Europe…and while both reindeer and caribou are of the same species, in North American, reindeer are generally referred to as the more domesticated, smaller subspecies of the caribou.
Caribou are often pictured living in a variety of different habitats, and some appear much larger than others. This is because there are seven subspecies of caribou which do differ quite a bit in size. They include:
- Barren-ground (Rangifer tarandus granti)
- Svalbard (R.t platyrhynchus)
- European (R.t. tarandus)
- Finnish forest reindeer (R.t. fennicus)
- Greenland (R.t. groenlandicus)
- Woodland (R.t. caribou)
- Peary (R.t. pearyi)
In Alaska, the Barren-ground is the primary subspecies of caribou, along with a small herd of the Woodland caribou, and they’re distributed among thirty-two different herds throughout the state. Canada, on the other hand, has three subspecies, including the Barren-ground, Woodland, and the Peary subspecies.
For most other members of the deer family, only the males have antlers. With caribou, however, both males and females grow antlers. The males, or “bulls,” as they’re referred to, typically have much larger antlers than the females, or “cows.” Bulls typically shed their antlers in late October through December when the breeding season is over, and females, by comparison, can end up hanging on to theirs until late winter or early spring. Like other members of the deer family, caribou grow their antlers back quickly over the summer and early fall months of the year.
Like other species of deer, caribou also make vocalizations. Cows and calves will grunt and huff back and forth to maintain contact with each other, and the bulls make a much lower, more guttural grunting sound, but mostly only during the breeding season.
Diet & Life Cycle
Since caribou are herd animals, they’re always on the move and looking for food. Caribou eat large amounts of sedge grass, leaves, mushrooms, lichens, and a variety of plants that grow out in the tundra.
The life cycle and overall characteristics of caribou can vary among the different subspecies and herds, as well as the different areas in which they live. Calves are typically born between the months of May and June and they can vary in color from dark brown, to light brown, or even reddish in appearance. Calves weigh an average of around thirteen pounds when they’re born and they grow rapidly. Calves can double their weight in only ten to fifteen days and caribou can grow considerably large when they reach maturity. Bulls average between 350-400 pounds and have been known to grow to a whopping 700 pounds, while the much smaller females average between 175-225 pounds.
When cow caribou are healthy and strong, they can breed when they’re as young as sixteen months old, but in most areas, they don’t start until they’re around two years old. Most cows get pregnant every year and give birth to one calf, with twins being a rare exception.
After giving birth to their calves, caribou gather in large groups, which helps them avoid predators such as bears, wolves, and even eagles, who especially prey on the young calves. One of the ways that caribou elude predators is by the cows in the herd giving birth to a large number of calves in a very short period of time, which tends to overwhelm predators. Yes, “safety in numbers,” certainly works at least somewhat for caribou. Another means of defense for caribou is that of swimming. Caribou have large, concave hoofs that can expand to give them traction and support in snow and spongy tundra, but they also work great as paddles, which enable them to out-swim predators who are hot on their trail.
During the summer months, the large caribou herds tend to stay in windy, cool areas, which greatly helps keep the horrific infestations of bugs away from them. When the weather cools off in the late summer and fall months, caribou spread out and feed aggressively in order to regain the weight they lose during the warmer months.
When late August and early September arrives, the big bulls shed the velvet from their antlers and get ready for the rut (breeding season) as well as their fall migration. Like other species of deer, when the rut kicks in, the necks of males swell up and testosterone levels greatly increase, making the bulls very aggressive. When this happens, bulls will start to fight for dominance and breeding rights. While most fights are relatively short and nobody gets seriously hurt, some battles do get incredibly violent, and even fatal. When the caribou bulls get worn out from breeding and fighting, it’s then that they get very suspectable to being attacked by predators such as wolves and bears.
The lifespan of caribou can differ quite a bit between the various subspecies and herds, but in general, the bulls live around eight years or so, and the cows typically live a bit longer, between ten to fifteen years.
So that’s a quick overview of the caribou of the North country. To watch the video version of this blog article, click here.