It's the holiday season, and this year I was lucky enough to travel up above the Arctic
circle where I saw some reindeer.
Now, while some magical reindeer may pull Santa's sleigh, your average, everyday reindeer
is pretty fascinating, too.
So today, let's talk about the bizarre side of reindeer that you may never have known
existed.
I'm Anna and this is a Gross Science.
One of the first things I noticed when I saw reindeer this year was that their antlers
were bloody.
To understand why, you need to know what antlers are.
Antlers are bony projections from the skulls of most male deer.
But reindeer are the only species of deer in which the females typically grow antlers,
too.
The antlers start out soft, and are covered in a layer of skin and hair called "velvet."
Blood flowing through the velvet can transport lots of oxygen and nutrients to help the antlers
grow quickly.
However, eventually the antlers harden, and the reindeer will scrape the velvet off—making
them look kinda like hangers covered in beef jerky.
A few months later, the reindeer will shed their antlers, and grow them anew the next
year.
In fact, depending on where Santa gets his reindeer, he might have an all-female sleigh
team—or a team made up of castrated males, called steers.
Intact male reindeer in many parts of the world will lose their antlers before Christmas,
while females and steers will keep theirs longer into winter.
Now, as you know, reindeer live in places with lots of snow.
So they have many adaptations to help them survive in this hostile climate.
One adaptation is the ability to see UV light, which is outside the spectrum of what humans
can see.
Snow and ice reflect UV, so to a reindeer, anything that absorbs it will appear black
and stand out in the snowy landscape.
And it turns out that lichens, which the reindeer eat, and urine and fur, which can be signs
of predators, all absorb UV light.
We still don’t know how reindeer protect their eyes from UV damage, though.
When humans encounter that much UV light, we can experience something called “snow
blindness,” which is basically a sunburn on your eyeball.
Reindeer may be very well adapted to their cold environment, but the climate of the Arctic
is changing.
And a multi-year study in Svalbard has found that global warming may have dire impacts
on reindeer populations.
As the climate warms, there’s more food available in the summer, which makes females
healthier and able to get pregnant more easily.
But warmer temperatures in the winter also means that rain falls more frequently on top
of the snow.
And when it freezes, it forms an icy layer that reindeer can't dig through to get to
the plants and lichen that they need to survive the winter months.
And that means that there isn't enough food to go around for all the reindeer mothers-to-be.
So, mothers have been giving birth to smaller calves, and even terminating their pregnancies
if they’re not getting enough food.
Climate change would not only be a problem for these animals, but also for the people
who rely on them.
Various northern indigenous groups have domesticated these animals, and used for transportation,
milk, meat, and fur.
And they’re still important for many people’s livelihood today.
So we shouldn't just think about reindeer over the holidays.
We should do what we can to protect them all year round.
Ew.
Hey everyone—one additional fact!
Caribou are technically the same species as reindeer.
But in North America we call wild animals “caribou” and domesticated animals “reindeer.”
The two can mate, but they do behave differently and have some physiological differences, as
well.
In Europe, however, wild animals in places like Svalbard are called “reindeer” and
not “caribou.”
Anyway, if you liked this video, give it a thumbs up.
If you have a question about reindeer, leave it in the comments.
And for more Gross Science, hit subscribe.