Caribou (or Reindeer)

Caribou, also called Reindeer in many European countries, are land mammals belonging to the deer family. Distributed around the Arctic and Subarctic lands on all three continents, there are about 15 subspecies of Caribou, varying sizes and colors. Both male and female caribou can grow antlers, a feature unique to them in the deer family. While many subspecies of Caribou are migratory, some subspecies, such as Woodland Caribou are sedentary. Owing to the wide changes in temperature from winter to summer, Caribou have developed seasonal adaptations, such as varying the weight and fat mass. This variation is also influenced by the breeding activity of both males and females. Caribous mate between September and November with a gestation period of about seven and a half months. Like deer, Caribou are ruminant with a four-chambered stomach eat leaves and grasses, but mostly lichen during the winter months. Caribous live on average about 15 years, with males living about four fewer years.

Caribou or Reindeer have been part of the life of many Indigenous peoples throughout the Arctic for thousands of years. Caribou bones make up a large portion of animal bones at many archeological sites in and around Arctic Circle. Many pre-historic communities settled along the Caribou migration routes. Many indigenous cultures have ceremonies associated with the caribou hunt. One common belief is that Caribous are under the control of a master (or Caribou man) and permission is required from the master to hunt the Caribou. Netsilik Inuit hunters were forbidden to hunt caribou in naturally formed crossing and thus will create crossing where Caribou will be hunted. In many beliefs, Caribou being land animals are thought to be natural enemies of sea animals and hence should not be cooked or eaten together.

Apart from the spiritual well-being, Caribou is central to life and is of great importance to Northern Indigenous communities. Almost the entirety of Caribou is used either as food (flesh and marrow), clothing (sinew and hide), or tools (antlers and tallow). Caribou meat is also preserved by hang drying or smoking during warmer months to prepare for the harsh winters when the catch is lean. The ways to prepare various parts of Caribou depend upon the Indigenous people. Not only the fermented content of the stomach is a delicacy in many cultures, but the stomach itself is used as a fermentation vessel. Many communities have either partially or fully domesticated caribou and maintain herds to meet their needs.

Caribou (or Reindeer) as a species are listed under vulnerable status, but some subspecies are more threatened than others. At least two subspecies, Dawson’s Caribou (subspecies dawsoni) and East Greenland Caribou (subspecies eogroenlandicus) are considered extinct. The populations of Caribou in the southern ranges of North America are increasingly under threat from human activities, including habit destruction, and disturbance. For example, the George River heard of the boreal woodland caribou, the largest subspecies in size once migrated around Nunavik (Northern Québec) and Nunatsiavut (Labrador) in numbers up to 800,000 - the second largest herd in the world. Since then, this caribou herd has shrunk by 99% to only 5,500 individuals in 2018. Through partnerships with various stakeholders, including provincial and territorial governments and First Nations, the Government of Canada is implementing strategies for the recovery of woodland caribou through protection and recovery of habitat. Early efforts could be responsible for the slight recovery of the George River herd to 8,100 individuals in 2020. Similarly, strategies for conservation are currently underway in Finland and the United States.

There are few large herbivorous animals in the Arctic tundra; and, as a result, such species represent a vital element of Arctic food security, Indigenous culture, and Arctic terrestrial ecosystems. Perhaps the most emblematic of such species is the caribou. Accordingly, this large ungulate has arguably received the most thorough genomic scrutiny of almost any Arctic terrestrial or marine animal. Canadian caribou consist of four different major populations: woodland caribou (including migratory woodland caribou), Grant’s caribou, Peary caribou and barren-ground caribou, organized into 12 designated management groups based on biological traits, all of which may be found to a greater or lesser extent in Arctic and sub-Arctic Canada. Whole genome sequencing of Pan-Canadian caribou discovered that there exist nine major genetic lineages, the genesis of which are tied to the splitting of populations and the movement of individuals to climatic refuges (called ‘refugia’) during the last Ice Age, some of which were able to host large populations of more cold-adapted caribou. This fragmentation of larger populations (genomic estimates of the effective population sizes of pre-glaciation caribou extend to > 1 million individuals (note: the ‘effective population size’ is an esoteric population and conservation genetics term with uses in describing the amount of genetic variation in a population, but may also be described as the theoretical minimum number of individuals that provide genetic variation for subsequent generations)) into smaller ones, followed by expansion, re-integration and migration among populations (gene flow), after the retreat of the glaciers, has facilitated high levels of within-species genetic diversity. However, the impact of glacial population dynamics reverberates today, resulting in high levels of potentially deleterious genetic variants (gene variants are called ‘alleles’) in the major lineages. Thus, contemporary populations carry a ‘genetic load’ that carries a real risk of reducing individual population reproductive success (called ‘fitness’ by biologists) through inbreeding, if populations become isolated or suffer a reduction in the number of breeding individuals (e.g., through loss of habitat, disease, climate change, over-hunting, or a combination thereof). The resulting inbreeding depression may push small populations into what is called an extinction vortex. Thus, genomics has highlighted that even genetically diverse species (and diversity has often been associated with the ability to adapt to changing environments), may carry a cryptic debt of deleterious genetic diversity (maladaptive or injurious alleles) that presents real problems and an ongoing danger for vulnerable sub-populations. This fascinating insight would have not been possible without modern whole genome sequencing methods.

Biologists at Canada’s ECCC, and associated universities, have developed a suite of genomics tools for the co-management of caribou populations in Canada (CaribouGenome – Whole genome sequencing and adaptive variation for conservation). Genomics tools, however, must be used alongside communities for whom the caribou is deeply embedded as an icon of Indigenous ways of knowing and living. Indeed, one of the earliest meetings of Indigenous and western knowledge (as defined as the science of genomics, genetics and biodiversity) to discuss the concept of biological and genetic variation, was between Dene and Métis communities and caribou geneticists. Together, these twin pillars of knowledge generation within Canada began to discuss the science of biodiversity and genetics whilst embracing the languages and cultures of Indigenous Canada. By learning together (Dene: Łeghágots'enetę), totemic icons of the Arctic and Canada, like caribou, stand an increased chance of living long into the future and remaining an important part of Indigenous and Canadian culture.