Caribou

4 to 5 feet (1.2 to 1.5 m)

Height

5.9 to 8.2 feet (1.8 to 2.5 m)

Length

240 to 700 pounds (110 to 318 kilograms)

Weight

About

The Caribou, scientifically known as Rangifer tarandus, is a species of deer native to the Arctic, sub-Arctic, tundra, boreal forest, and mountain regions of North America, Europe, and Asia. It belongs to the Cervidae family, which includes other deer species such as moose, elk, and reindeer. Within the Animal Kingdom, caribou are classified under the order Artiodactyla, alongside other even-toed ungulates like giraffes and camels.

Caribou are well-adapted to cold climates, possessing thick fur and large, concave hooves that aid in traversing snow and ice. They undertake long seasonal migrations, traveling vast distances between summer and winter ranges in search of suitable forage. These migrations are crucial for accessing food resources and avoiding predators.

Caribou exhibit sexual dimorphism, with males typically larger and bearing impressive antlers used for dominance displays and during the mating season. Females also grow antlers, although they are generally smaller and shed them after calving.

Conservation Status

The conservation status of caribou varies among subspecies and populations. Several subspecies, particularly those inhabiting North America, face significant threats due to habitat loss, climate change, predation, and human disturbance. As a result, many caribou populations have experienced declines in recent decades.

The International Union for Conservation of Nature (IUCN) Red List categorizes caribou under various statuses, depending on the specific population or subspecies. Some populations are listed as endangered or vulnerable, while others may be of least concern. Conservation efforts focus on habitat protection, predator management, and mitigating human impacts to ensure the survival of caribou populations across their range. Continued monitoring and collaborative conservation strategies are essential to safeguard these iconic Arctic ungulates for future generations.

Threatened:

Physical Characteristics

Caribou, also known as reindeer, are large, hoofed mammals known for their distinctive antlers and suitability to cold climates. Here is a description of the typical physical appearance and measurements of a caribou:

Size: Adult caribou can vary in size, but they typically measure about 4 to 5 feet (1.2 to 1.5 meters) at the shoulder. From head to tail, they range from 5.9 to 8.2 feet (1.8 to 2.5 meters) in length.

Weight: The weight of caribou can vary widely depending on the subspecies and sex. They can weigh anywhere from 240 to 700 pounds (110 to 318 kilograms), with males generally being larger and heavier than females.

Body Shape: Caribou have robust and stocky bodies with relatively long legs, which support their migratory lifestyle and agility in snowy environments.

Fur: Their fur is thick and dense, providing insulation against the cold. It varies in color from dark brown to nearly white, aiding camouflage in their Arctic and Subarctic habitats.

Head: Caribou have broad heads with large eyes and a short, wide snout. Both males and females grow antlers, which is a unique characteristic among deer species.

Antlers: The antlers are large and elaborate, with males sporting more prominent antlers than females. They are typically shed and regrown annually.

Tail: They have short tails, covered with the same thick fur as the rest of their body.

Adapted to traverse vast and frigid landscapes, caribou are well-equipped for survival in the harsh conditions of the tundra and boreal forests. Their hooves are broad and act like snowshoes to prevent sinking into the snow, and they can dig through snow to find food sources like lichen.

Reproduction

Caribou, also known as reindeer, have a reproductive cycle that is intricately linked to their migratory patterns and the extreme environments they inhabit. Here are the key aspects of their reproductive cycle:

Breeding Season: The breeding season, or rut, for caribou usually takes place in late September to early November. During this time, males, known as bulls, compete for the attention of females, known as cows, through displays of dominance and physical contests.

Rutting Behavior: Bulls engage in battles by locking antlers with rivals to establish a hierarchy and gain the opportunity to mate with multiple females. The rutting behavior is intense and can be taxing on the bulls, often leading to significant weight loss.

Gestation: After successful mating, the gestation period for caribou lasts approximately 230 days (about 7.5 months). This timing ensures that the birth of calves coincides with the period of peak food availability in their habitat, typically in late May or early June.

Calving: Caribou generally give birth to a single calf each year. Twins are extremely rare. The calving period is synchronized across herds, leading to many calves being born within the same week, which can reduce predation risk through safety in numbers.

Maternal Care: Caribou calves are precocial, meaning they are relatively mature and mobile shortly after birth. They are able to stand and nurse within hours, and quickly join the herd in migration. However, they remain dependent on their mothers for milk for several months.

Social Structure: Outside of the breeding season, caribou herds are segregated by sex. Bulls form bachelor groups or roam alone, while cows and calves stay in maternal herds. The herds merge during the rut and then separate once again.

Lifespan: Caribou can live up to 15 years in the wild, though many do not reach this age due to predation, harsh weather, and other environmental factors.

The reproductive cycle of caribou is a critical component of their survival in the subarctic and arctic regions. The synchronization of mating, calving, and migration patterns with the seasonal changes in their environment highlights the caribou’s remarkable adaptation to their ecosystem.

Lifespan

The lifespan of Caribou, known in some regions as reindeer, can vary depending on environmental conditions and the presence of predators. Here is a general overview of their lifespan:

Wild Caribou: In the wild, caribou have an average lifespan of around 4 to 15 years. However, a significant number of calves do not survive their first year due to predation and harsh conditions. Adult survival rates are influenced by the quality of their habitat and the degree of protection from predators.

Captivity: Caribou in captivity, where they are protected from predators and harsh weather, and receive regular veterinary care, can live longer than their wild counterparts. In a controlled environment, they can live up to 20 years or more.

Factors Affecting Lifespan: The lifespan of caribou in the wild is affected by various factors, including:

Predation: Predators such as wolves, bears, and humans pose significant risks to caribou, particularly targeting calves and sick or old individuals.
Food Availability: The availability of their primary food sources, like lichen and other tundra vegetation, is crucial for survival, particularly in winter.
Habitat: The quality of their migratory routes and calving grounds, along with environmental conditions, greatly influences their lifespan.
Reproduction: Caribou reproduce annually, and the energy demands of migration, rut, and calving can have an impact on their overall health and longevity.

Biggest Threats: The most significant threats to caribou include habitat destruction due to mining, forestry, and oil extraction; climate change affecting their food sources and migratory patterns; and increased predation. Human hunting and vehicle collisions also pose direct threats. Conservation efforts, such as habitat protection and sustainable hunting practices, are vital for ensuring their survival in the wild.

Eating Habits

Caribou are herbivores with specialized diets that allow them to survive in the harsh conditions of the tundra and boreal forests. Here’s an overview of their eating habits:

Diet:

Lichen: Caribou are particularly fond of lichen, often referred to as “reindeer moss,” which they forage for under the snow. This slow-growing plant is a crucial food source, especially in winter.

Grasses and Plants: During the warmer months, their diet expands to include a variety of grasses, herbs, ferns, mosses, and the leaves of willow and birch trees.

Shrubs and Berries: They also consume shrubs and berries when available, supplementing their diet with more nutrients and variety.

Hunting Behavior: As grazers, caribou don’t hunt but have specific foraging behaviors:

Digging: In winter, caribou use their large, concave hooves to dig through the snow to reach the lichen and other vegetation beneath.

Migration: Caribou undertake long migrations to access seasonal food sources, moving to different areas where food is more plentiful.

Grazing: They spend a large portion of their day grazing. Their flat molars are perfect for grinding down plant material.

Selective Feeding: Caribou are selective feeders during the summer when food is abundant, choosing the most nutritious plants available.

Dietary Needs: Caribou have adapted to an energy-efficient diet that sustains them in their cold environments. They have a four-chambered stomach that allows them to ferment food and extract maximum nutrients.

Caribou are a keystone species in their ecosystems, with their foraging habits impacting the plant communities and thus the overall health of the environment. Their movements and feeding patterns also influence the structure of the vegetation and soil in the areas where they graze.

Uniqueness

Caribou, known in some regions as reindeer, are truly unique animals with several characteristics that distinguish them in the animal kingdom:

Antlers: Both male and female caribou grow antlers, a rarity among deer species. The males’ antlers can be very large and are used during rutting season battles, while females use their smaller antlers for foraging in the snow.

Adaptation to Cold: Caribou have adapted to life in extremely cold environments. Their fur traps air, providing excellent insulation, and their noses warm incoming cold air before it reaches their lungs.

Migratory Patterns: Caribou are famous for their long-distance migrations, some covering over 3,000 miles annually, which is one of the longest of any terrestrial mammal.

Hooves: Their large, concave hooves act like snowshoes to support them in soft snow and tundra. The edges are sharp for breaking through ice to find food, and they can even be used as paddles when swimming.

Social Behavior: Caribou are highly social and travel in large herds, which offer protection against predators. Their herding instinct is a key survival trait.

Diet: They have a specialized diet primarily consisting of lichen during winter, which they can smell through snow, and a variety of tundra vegetation in summer.

Cultural Significance: Caribou have a profound importance in the culture and subsistence economy of Indigenous peoples of the Arctic and Subarctic.

Survival Tactics: In harsh winter conditions, caribou dig craters in the snow to find food, showing their adaptability and resilience.

Sensory Adaptations: Caribou have excellent senses, including sharp vision and hearing, which are crucial for survival in their predator-rich habitats.

Conservation Status: They are an indicator species for the health of the boreal and Arctic ecosystems. Changes in caribou populations can signal shifts in environmental health.

These unique characteristics enable caribou to thrive in some of the most inhospitable climates on Earth, reflecting their evolutionary success as a species. They are an iconic symbol of the Arctic wilderness and are integral to its ecology.

Caribou Pictures

See All Pictures

FAQ’s

Yes, caribou and reindeer refer to the same species, scientifically known as Rangifer tarandus. However, the terms are often used to describe different populations of this species, with some regional and behavioral differences:

Caribou: In North America, the term “caribou” is used to describe the wild, migratory populations. North American caribou are typically larger and have adaptations for long-distance migrations. They roam freely in the wild and are not typically domesticated.
Reindeer: In Europe and Asia, particularly in Scandinavia and Russia, the term “reindeer” is used. These animals are often semi-domesticated and have been herded for centuries by indigenous peoples, such as the Sámi in northern Europe and the Nenets and Chukchi in Russia. Reindeer are generally smaller and more sedentary compared to their North American counterparts.

The domestication is the key distinction, with reindeer being used for transportation, meat, milk, and hides. In contrast, caribou are primarily wild animals and not used in the same way, although they are still significant to the indigenous cultures of North America for subsistence and cultural reasons. Despite these differences, genetically and biologically, caribou and reindeer are the same species.

Caribou, also known as reindeer, exhibit several unique characteristics that distinguish them from other members of the deer family (Cervidae):

Antlers on Both Genders: One of the most distinctive features of caribou is that both males and females grow antlers. In most other deer species, only the males have antlers.
Adaptation to Cold Climates: Caribou are exceptionally well-adapted to cold environments. Their fur is denser and provides better insulation compared to other deer. They also have large, fur-covered hooves that function as snowshoes and help them traverse snowy landscapes.
Migratory Behavior: Caribou are known for their long migratory patterns, covering greater distances than any other terrestrial mammal. Other deer species may migrate seasonally, but typically over shorter distances.
Diet: While all deer are herbivores, caribou have a specialized diet that includes a significant amount of lichen (reindeer moss), especially in winter. This diet is unique among deer species.
Social Structure: Caribou often travel in large herds, particularly during migrations. This social structure is more pronounced compared to other deer, which may form smaller groups or be more solitary.
Size and Build: Caribou are generally larger and sturdier than many other deer species, with a body structure that supports their migratory lifestyle.
Role in Human Culture: Caribou have a unique relationship with humans, especially in the Arctic and Subarctic regions. They are semi-domesticated in some areas and have been integral to the survival and culture of indigenous peoples for thousands of years, which is less common with other deer species.
Conservation Status: The caribou’s habitat, largely in the Arctic and boreal regions, is particularly sensitive to climate change, making them more vulnerable to environmental shifts compared to other deer that inhabit more diverse and less fragile ecosystems.

Overall, while caribou share many basic characteristics with other deer, such as being ruminants with similar body shapes, their adaptations to cold climates, unique diet, migratory habits, and cultural significance set them apart.

Related Family Species

Sources

Britannica, Caribou, https://www.britannica.com/place/Caribou, retrieved January 2024.
Burnie, David & Wilson, Don, Animal, Smithsonian Institute, Washington DC.
Clutton-Brock, Juliet and Wilson, Don, Mammals, Smithsonian Handbooks, New York, NY.
Hickman et al, Integrated Principle of Zoology, McGraw Hill, Boston.
Paragon, The Ultimate Guide to Wildlife in North America, Atlantic Publishing, UK.