Caribou migration: what is it and why are they doing it?

When we think of migration, we usually think of birds flying south for the winter, but there are actually other animals, in particular some species of caribou. Rangifer tarandusalso migrate. However, unlike birds, which primarily avoid harsh winter weather and temperatures, caribou migrate for a variety of reasons.

One of the reasons caribou migrate is to travel to distant birthplaces. This is done so that their newborn cubs are protected from predators from golden eagles, wolves and grizzly bears in the most vulnerable first days of the cubs’ life.

Another reason for their journey is to get to the northern ice fields to stay away from mosquitoes that might infect them during the warmer months. Finally, they return south when it gets colder.

Migration also allows them to avoid overgrazing in certain areas and gives the animals the opportunity to eat whatever food grows the most in each season. For example, in the winter, their diet will consist mainly of abundant lichens, better known as deer mosses.

What is a caribou?

If the term “caribou” is unfamiliar to you, perhaps their other name is more familiar to you. These relatives of reindeer are also known as reindeer, which almost certainly explains why the lichen they feed on in winter is called reindeer moss. In North America, they are usually called reindeer only when domesticated, whereas the free-roaming wild herds are called caribou. Their scientific name consists of two different words for “reindeer”: one Latin and the other New Latin.

Some interesting facts about caribou, including that they are the only animals in the world known to see ultraviolet light, and they are the only member of the deer family in which both males and females the horns grow. …

These animals also live for about 15 years, weigh up to 700 pounds, and even at one day of age can reach speeds faster than human sprinters. Unfortunately, despite their high population, their survival is potentially threatened by Arctic drilling. While some species appear to be thriving, others are considered endangered and endangered.

Caribou herd facts

The largest herd of caribou is probably the Western Arctic herd, which at its peak numbered almost 500,000 but still numbers around 260,000. Its migratory territory covers more than 150,000 miles from Alaska, an area larger than the entire state of California.

Perhaps the most famous of the migratory herds of caribou are the porcupine herds in Alaska, located primarily in the Arctic National Wildlife Refuge and named after the river they migrate along. There are almost 200,000 of them, and on their way they traverse an area the size of Wyoming on the map, through a refuge in Alaska, as well as parts of the Northwest Territories and the Yukon in Canada.

In contrast, the Central Arctic caribou herd numbered only about 22,000 at last count in 2016, up from 70,000 just six years earlier. Not all Central Arctic herds actually migrate, and those that do have a large roaming area.

Scientists use a radio-tracking collar on select members of the herd and also take photographs from low altitudes to track their migration every year. These trackers have taught biologists a lot about the travel habits of these intriguing creatures. In July 2003, it took a team of 13 biologists with four airplanes and a large mapping camera to count herds in the Western Arctic. They took over 1,000 photographs to accurately estimate the numbers.

Scientists keep a count of the livestock every three years, weather and conditions permitting. This allows them to know whether the herd population is increasing or decreasing, and whether the migration patterns have changed significantly from the previous census.

When do caribou migrate and how far?

The typical caribou migration route for various North American species begins in the spring, in April. It is then that the pregnant cows and the rest of the herd begin their 400-mile journey to the herd’s specific ancestral fields, which are located on the Arctic coastal plain for the porcupine herd. Often, only maternal cows make the full journey to the calving site, and males and non-mothers remain on the outskirts of the land until migration begins again.

The next stage of their migratory journey begins in the summer, in late June or early July, when biting pests known as mosquitoes begin to hatch in large numbers. To avoid endless bites, caribou travel further north at this time, to the ice fields near Brooks Ridge, which are too cold for mosquitoes to survive. They will only stay there for a few weeks before heading back south to where they plan to spend the fall and winter.

This changes from year to year and sometimes happens at a porcupine herd sanctuary in Alaska, and sometimes in Canada. In total, their path along the map takes about 3000 miles.

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