“Reindeer” is a familiar name to most people, due to the
animal’s association with Santa Claus and Christmas. However, relatively few of
those people know much about the real animal (or believe that Reindeer are real
at all.) So, what are actual reindeer like, and why are they so special? Let’s
go!
Reindeer, also known as Caribou, go under the Latin name of Rangifer
tarandus. They are members of the deer family (Cervidae), though are not
particularly closely related to other deer. And yes, Reindeer and Caribou are
the same animal. Reindeer are what as known as a “circumpolar” species. That
is, they are found in the arctic all the way around the world. So, the northern
reaches of North America, Europe, and Asia.
(Current range of Reindeer/Caribou)
So why are they called ‘Caribou’ in North America? Well, the
name Caribou is an anglicization of the Mi’kmaq ‘Qalipu’, which means something
like ‘snow shoveler’. (Referring to the way they use their front hooves to dig
through snow to reach food). The first Europeans to encounter these animals in
North America were French colonists, who likely had never seen a real reindeer.
(Though reindeer were historically found in France, as evidenced by prehistoric
cave paintings, they left the area and retreated north at the end of the last
Ice Age.) So, these French people, upon encountering a new, unfamiliar animal,
adopted the local Native American name.
(Reindeer and other ungulates in France's Chauvet-Pont-d'Arc Cave, painted by neolithic humans over 30,000 years ago.)
Sometimes, people claim that ‘Caribou’ is used for wild
animals, and ‘Reindeer’ for domestic. This is only true in North America.
Because North American caribou have never been domesticated, people seeking to
keep domestic herds imported reindeer from Europe. Hence continuing to call
them Reindeer even after arrival in North America. There are populations of
wild, never domesticated reindeer in Europe and Asia. Though local dialects
will often have different words for the wild and domestic animals, in English
they are all reindeer.
(Infographic comparing wild and domestic Finnish reindeer, at the zoo in Helsinki)
There are about 17 subspecies of reindeer recognized. There’s
discussion over whether some populations are genetically distinct enough to be
considered separate species, but currently they are all still considered Rangifer
tarandus.
During the last Ice Age, reindeer were found as far south as
France and were an important food source for early humans migrating into Europe
and Asia. Currently, reindeer are found in the northern reaches of Asia, Europe,
and North America.
Like all arctic animals, Reindeer have a range of very
specialized adaptations for dealing with the environment. The most obvious is
their fur. Reindeer fur is very thick, and composed of two layers. The outer
coat is made up of stiff guard hairs, which shed snow and protect the soft,
fluffy undercoat. (If you’ve ever owned a double-coated dog, you know what I
mean). Air pockets make excellent insulators, so the air trapped in the fluffy
undercoat help Reindeer keep warm even when its bitter cold outside. Their hair
is also hollow, providing even more insulating air pockets. Reindeer can keep
perfectly comfortable in temperatures of -40, and all the air trapped in their
coats also makes them incredibly buoyant. Reindeer are very good swimmers,
which is important, as they often have to cross rivers and lakes during their
migrations.
(Domestic herd in Norway making their way to winter feeding grounds. https://www.behance.net/gallery/109646699/Swimming-Reindeer-Of-The-Norwegian-Arctic )
In the winter months, reindeer fur is at its thickest.
Reindeer are typically light brown with white manes and undersides, and dark
brown stripes on the sides, legs, and face. Though, some populations are
lighter in color than others, with some (like the Svalbard reindeer) being
nearly all white. Domestic reindeer can also display unusual coat patterns,
like piebald and pure white.
(Domestic reindeer sometimes have white patches not seen in wild populations)
In the late spring, reindeer shed their winter coat in big
chunks and wear a much thinner, darker coat for the summer so they don’t
overheat.
(Female reindeer shedding to a dark summer coat)
Of course, reindeer fur being such a good insulator has also
been very useful to humans as well. For thousands of years, people of the high
north have made clothing out of reindeer and caribou hide. This warm clothing
is the reason humans have been able to survive in polar regions.
(Canadian Inuit woman's outfit of caribou hide)
(Traditional reindeer skin boots of the Sámi people. The curled toe keeps the boots from slipping out of ski bindings)
There are also other ways that Reindeer change to fit the
seasons. In the summer, they have a large, fleshy pad between their hooves.
This is important, because much of the tundra is soft and swampy in the summer
after the ice melts. In the winter, that fleshy pad shrinks, so that its only
the hard edge of their hooves against the snow and ice.
Their eyes change as well. Reindeer have the same horizontal
pupils of other ungulates (hooved mammals), but they have to deal with long
periods of darkness during the winter. Above the arctic circle, there can be
anywhere from days to weeks of Polar Night where the sun doesn’t rise at all. In
the back of the eye of many animals is the tapetum lucidum, which reflects
light back into the retina for better low-light vision. (This is why the eyes
of many animals seem to shine or glow at night when a light is shone on them)
Most of the time, the tapetum lucidum is brown. And indeed,
reindeer in the summer have deep chocolate eyes. However, in the winter,
reindeer eyes change to blue. Not the iris, but the tapetum lucidum, which reflects
blue light and makes the eyes many times more sensitive to light to help
reindeer see in the darkness. As their pupils dilate for long periods of time
in the winter, the pressure inside the eyeball increases and the wavelengths of
light being reflected change with it. Too cool!
(Tapetum lucidum's winter vs summer)
Reindeer can also see into the UV spectrum, one of the few
mammals known to have this ability. This is very useful because, while to us
humans the winter in the arctic looks like an endless sea of white, to
reindeer, things such as the white of snow and the white fur of an arctic wolf
are different in UV. Very important to reindeer who are looking to avoid
getting eaten. Reindeer lichen, their favorite food, absorbs UV instead of
reflecting it, so Reindeer can see it as dark spots in the snow in addition to
sniffing it out.
Another important insulator against the cold is their big,
squishy noses. Reindeer have the most boopable snoots, and their noses are
completely fur covered. (No, reindeer do not have black dog-like noses, as most
other deer do, every Christmas cartoon ever has lied to you. A moist, hairless
nose would freeze instantly).
If you look inside the nose of a reindeer, you will find a
maze of channels the air has to navigate. Arctic air is very cold and very dry
(the colder air is, the less moisture it can hold, which is why its never cold
and humid at the same time). When a reindeer breathes in, they don’t want that
cold, dry air in their lungs. They’re working very hard to keep their organs
warm, after all. So, as air passes through their nasal labyrinth, the air is
heated and moisture added so that it doesn’t cold shock their lungs.
And then the opposite happens when they exhale. Have you
ever breathed out on a cold day to watch your breathe fog in the air? That’s
heat and moisture leaving your body. But when a reindeer breathes out, their
nose reabsorbes all that heat and moisture so that the air is cool and dry
again once more.
Conserving heat to the brain and internal organs is crucial
for any mammal. So, reindeer legs are also designed for that. Their legs are a
lower temperature than the rest of their body, and they help keep it that way
by having veins that are very close together. Warm blood headed towards the
legs heats up the cool blood returning to the heart, so the reindeer doesn’t
have to work so hard to keep their core warm.
Reindeer legs are pretty cool in another way. If you ever watch
reindeer walking around, they don’t vocalize much, but you do hear a regular
click click click sound. That is from tendons in the reindeer’s legs. As they
put weight on their hooves, a tendon slips over the bone with a Click! Kind of
like a human cracking their knuckles. These clicking sounds help the herd find
each other in white-out conditions. They are also louder the heavier a reindeer
is, so they are a good way to judge whether another deer is stronger without
having to resort to a fight.
Their legs are pretty awesome in other ways too. Some
populations of caribou make the longest migrations of any land mammal. The Porcupine
Caribou herd (named after the Porcupine river) migrates 1,500 mi
(2,400 km) annually across Northern Canada and Alaska to go from winter
feeding grounds to summer calving grounds and back. This herd numbers more than
200,000 animals and can cover miles a day.
(Range of the Porcupine Caribou herd. If the US allows oil drilling in the Arctic National Wildlife Refuge, it would wipe out a large portion of the herd's calving grounds)
Other populations of Reindeer, like those who live in the
forests or in mountainous areas, make smaller seasonal movements in their territory,
but Reindeer are always on the move.
This is because of what they eat. Reindeer are one of the
few animals that survive primarily on lichen. A curious symbiosis of fungus and
algae, lichen can survive in even the harshest environments. Including grow on
bare rock, on the bark of trees, and yes. On the arctic tundra.
The favored food of most reindeer is the appropriately named
Reindeer Lichen, Cladonia rangiferina. The name is also used for
the related Cladonia portentosa. Sometimes also called Reindeer
moss, these are both lichens. They grow in fluffy bunches along the ground in
boreal forests and on the tundra, and reindeer hoover them up eagerly. However,
like most lichens, reindeer lichen grows extremely slowly. Less than half an
inch a year. Which means once reindeer graze an area, it can take years for the
lichen to re-grow. Reindeer are constantly on the move as a result, eating in
one area before moving on to prevent over-grazing all the lichen in one area. In
the winter months, reindeer use their large front hooves to dig down through
the snow to reach the lichen underneath.

There are also reindeer who live in forests and on
mountains, including the Mountain Caribou of the inland rainforests of the
Pacific Northwest. In this environment of towering, old growth trees, caribou
prefer arboreal lichen. That is, lichen that grows on the limbs of trees. Their
favorite are beard lichens (Such as Alectoria sarmentosa and other long,
draping arboreal lichens), which hang down from the branches of trees like long
beards or curtains. Mountain caribou will actually move downslope in the
autumn, then return to high elevations in the winter once the snow is deep enough
for them to stand on top of it and reach lichens even higher in the trees.

Of course, reindeer do eat foods other than lichen. Like all
deer, they also enjoy the fresh, young buds and leaves of plants. Particularly
the fresh leaves of birch trees, which they consume with great relish. Reindeer
are also big fans of mushrooms, including, infamously, the Fly Agaric mushroom.
Though toxic to humans, it is a favorite treat of reindeer. These mushrooms are
also highly hallucinogenic, though it’s unknown whether this actually affects
reindeer. (And no, reindeer eating red mushrooms with white dots and going on
drug-induced wild trips is not why Santa Claus wears red and white and is
pulled by flying reindeer. I’m sorry. You can learn more about the actual
origin of Santa in my previous blogposts on his history)
It is the reindeer’s ability to survive on a diet of lichen
that has allowed them to expand and thrive in environments too hostile for any
other deer species.
Reindeer are also, famously, the only domesticated species
of deer. Domestication is a long, complex process in which humans control the
breeding of a species of animal over many generations to produce something more
suited to their purpose. It is different than taming, which is just habituating
an animal to be used to humans. Taming is done to the individual, but
domestication is a multi-generation process done to an entire population.
The exact date when an animal was domestication is hard to
pin down, but we do know that reindeer are one of the most recent cases of
animal domestications. It’s estimated that reindeer domestication started
around 3,000 years ago in Siberia. We’re still not sure if these deer then
spread across Europe and Asia, or if the Sami people of northern Europe
domesticated reindeer independently at the same time.
Originally, reindeer were domesticated for meat and hide. Humans
living in the north have survived on hunting reindeer for many thousands of
years, and keeping your own herd is easier than hunting them down. Then you
have meat for food, and furs for clothing and shelter. But reindeer also make
good draft animals. They are used to pull sleighs, of course. People who depend
on reindeer must be nomadic, following the deer as they move frequently to new
feeding grounds. So, packing up your house and transporting it on reindeer-drawn
sleigh is the best way to keep up with the herd on the move.
In parts of Mongolia, the Tsaatan people live in mountainous
regions where sleds are not practical, so they instead use saddles on their
reindeer. Gear is secured to pack saddles, and the people ride reindeer like
horses as well.
Reindeer are smaller than typical horses (people often
express surprise at how small actual reindeer are compared to their mental idea
of them), but large males can carry a surprising amount of weight.
Though dog sleds, used by many Arctic peoples, is much
faster than traveling by reindeer sled, an advantage of reindeer is that you
don’t have to feed them. When you stop for the night, you can tie off the
reindeer and they will dig up their own food. Reindeer are quite fast for short
periods, like many deer, and can hit the speeds of a racehorse in sprints, but
cannot keep up those high speeds for extended periods of time like specially
bred sled dogs.
(Nenets family in Siberia moving their herd and home to new pastures via reindeer sleigh. Photo © Richard Deman)
Herding reindeer is still a way of life for many indigenous
groups of the Eurasian arctic, though the introduction of snowmobiles mean that
most families no longer travel with their herds. The Sami, who’s land stretches
across the northern portions of Norway, Sweden, Finland, and Russia’s Kola
Peninsula, are probably the most well known group of traditional reindeer
herders.
Though Sami families now live in permanent housing, their
reindeer still free range across the landscape. It’s not uncommon to see them
traveling the hiking trails of National Parks, hanging out in the middle of the
highway, or wandering through people’s yards. But these are not wild deer, they
are all owned by someone.
Herders tell their deer apart using earmarks. Every herder has
their own unique earmark, a set of notches cut into the ears of the deer. Twice
a year, all of the herders in an area get together for a cooperative drive,
rounding up all of the reindeer into pens and sorting them out by owner. In the
spring, it’s a chance to look over the new calves and give them their earmarks.
In the fall, animals are separated out for slaughter.
(Examples of types of ear cuts in Finland. Different cuts can be combined into endless combinations, each unique to a particular herder)
Reindeer have a harem mating system, like other deer. This
means that one male gathers a group of females, and fights off any other males
that may attempt to mate with them. A bull reindeer’s antlers are the signal of
how fit they are, with the largest rack winning in a showdown. But if no one
backs down, then the antlers are used to grapple. Interlocking with eachother,
the males will attempt to twist and force the other to the ground.
(Bull caribou fighting in Jasper National Park.
: Mark Bradley)
The mating season, when males go into rut and stop eating in
order to focus everything on fighting and mating, occurs in the fall. When
winter comes, all of the females are pregnant, to give birth the spring, while
the males have expended much of their energy and fat reserves and may struggle
to survive the winter.
Because only one male breeds many females, herds can be
maintained at a very lopsided ratio. Sometimes 1 male to every 30-60 females. Herders
select which bulls will be allowed to breed that year, the others will be slaughtered
or castrated. Castrating the males prevents them from entering rut, and thus expending
all of their energy each fall, so they are more docile and maintain better body
condition. This is more desirable in an animal to be slaughtered, but is also
done to sleigh deer. Young males will be chosen for sleigh training, castrated,
and then trained to pull sleighs. These days, though, sleigh pulling reindeer
are mostly used for tourist rides in Europe.
(Tourists in Finland can go for a reindeer sleigh ride)
One of the noticeable unique things about reindeer is that,
unlike any other species of deer, both males and females grow antlers. Bull
reindeer grow the largest antlers (compared to body size) of any deer, and many
females develop pretty massive racks as well. Since antlers are primarily used
for signaling and fighting rivals of the same species, why do the females have
them too?
Well, it has to do with the harsh environment reindeer have
evolved to survive in. During the winter, food is scarce and difficult to find.
It’s important for the pregnant females to get plenty of nutrition if they are
to have healthy calves in spring. Since deer with antlers are higher in the
social structure of the herd than those without, pregnant females with antlers
can bully others away from the best feeding sites. The males, having already
bred, drop their antlers by midwinter and move down to the bottom of the herd
hierarchy.
(Male reindeer following behind a female)
Reindeer have a single calf in the spring, born after about
230 days of pregnancy. A female reindeer leaves the herd to give birth, finding
an isolated place hopefully far from predators. Reindeer calves have soft, dark
coats and can stand on their own soon after birth. By the time they are a week
old, reindeer calves can outrun any predator.
(Newborn calf with mom.
Jim Schulz / Chicago Zoological Society)
Just like a cow, reindeer have an udder with four teats,
though they only nurse a single calf at a time. Their milk is very rich in fat,
helping the calf grow quickly so that they will have the reserves to survive
the coming winter after they are weaned. Domestic reindeer are also sometimes
milked by their herders, though they have not been bred for milk like modern
dairy cattle, so the amount they give is fairly small.
(Tsaatan woman Otgontsetseg milking one of the reindeer in her herd.
Photo by Breanna Wilson)
In the spring, as life erupts across the Arctic with the
melting of the ice, reindeer are still continuously on the move. Even when food
is abundant, the reindeer don’t stay in one place for long. With the melting of
the ice also come the biting insects. Mosquitos are infamously large and
ravenous in the arctic, along with other blood-sucking bugs, which harass
reindeer endlessly. To escape the swarm, reindeer migrate into the wind, since
most insects are poor fliers in wind, and will chew their cud while standing on
patches of permanent snow and ice where the chill keeps away the insects.
(Herd standing on a snowpatch for relief from insects
http://bjornfree.com/galleries.html )
Different populations of reindeer and caribou have different
seasonal patterns, from the many-thousand-mile walks of Barren Ground Caribou,
to the season up and down movements of Mountain Caribou. They are also
different sizes, depending on environment and resources. The largest are the
Southern Mountain Caribou of the inland Pacific Northwest, 4 feet tall at the
shoulders with weights of 250-over 400 pounds. (1.2meters, 110–210 kg) and
are dark in color. At the other end of the spectrum is the Svalbard Reindeer,
found only on the Svalbard Islands, who reach 3 feet at the shoulders, and
weigh 110 – 200 pounds (1 meter, 53-90 kg). They are also the lightest in
color, nearly white with darker grey markings, a feature they share with the
almost as tiny Peary Caribou.
(Svalbard reindeer are the smallest, and chonkiest, population)
Though Reindeer are widespread around the arctic, both
domestic and wild populations are facing challenges today. Climate change, and
a warming arctic, have caused declines in many tundra species of reindeer. When
temperatures are warmer than normal in the winter, layers of snow may thaw
during the day before refreezing at night, creating layers of ice. Freezing
rain also falls, instead of snow, coating the landscape in ice. Reindeer are
well designed for digging through snow to find their lichen food, but have
trouble breaking through ice layers, so if the snow frequently melts and
refreezes, the reindeer starve.
Woodland and Mountain caribou, who live in the thick forests
and up on mountains in the lower reaches of their range in North America, face
other issues. Mainly, habitat fragmentation due to logging. These caribou rely
on arboreal lichens, which are most abundant in old-growth forests. It can take
a patch of forest 100 years to grow enough lichen to support caribou, so
logging patches of forest has a strong impact on caribou. These lichens are
also very sensitive to air pollution, and won’t reach their full size without
clean air. New growth is also attractive to other species of deer (Such as
white-tailed deer and Wapiti/ American Elk) who prefer to eat fresh growth. And
with other species of deer, come their predators. Caribou rely on remaining at
high elevations while other deer retreat lower, because the predators will
often also retreat to follow the other deer species. As deer roam higher into
the mountains, aided by logged corridors and lower snowpacks, they bring predators
with them.

(A rare Southern Mountain Caribou peers through the trees in the Selkirk Mountains. Photo by Bryce Comer)
Winter recreation, like snowmobiling and heli-skiing, are
also very disturbing to the Mountain Caribou, adding extra stress as they flee
from the intrusion. Caribou are now gone from the lower 48 states, except for a
small population along the northern border of Washington and Idaho. Non-profits
and First Nations groups are seeking to help the Mountain Caribou through
initiatives like preserving old growth forest from logging, negotiating areas
where snowmobiles and helicopters are banned, and the use of maternity pens. (Multi-acre
fenced areas where pregnant caribou can be kept safe from predators and
provided food until they give birth. Once the calves are 3-5 weeks old and past
the high-risk age, they and their mothers are released). Find out more about
how you can help! : https://caribourainforest.org/act-today
Alright, that's all for now! There's more to say about Reindeer and their association with Christmas, but that will have to wait for the next blogpost.