An animal so powerful they named a siege weapon after it.
A mountain climber who goes toe-to-toe against North America's greatest predators.
A social animal trying to make an unlikely comeback.
This is the wrecking ball of the rockies: the bighorn sheep.
Hi, I'm Danielle Dufault and you're watching Animalogic.
Today we're in Banff National Park and we just found a whole herd of bighorn sheep.
The breathtaking rocky mountains are one of the best habitats for the metalheads of the mountains,
the bighorn sheep.
These ungulates are one of the two native sheep species of North America.
Both species are descendants of Asian sheep
who crossed the Bering Strait less than a million years ago.
But while their closest relatives, the Dall sheep, stayed relatively close to home, in the
northwestern parts of the continent, the bighorn sheep took over the continent's mountain ranges,
from British Columbia, Canada, to Baja California, Mexico.
Bighorn sheep have been in North America for a long, long time.
Back in the Pleistocene era, they crossed on the Bering land bridge,
from Siberia all the way to Alaska, and dispersed all through North America.
Sticking around now mostly in the rockies,
and this is why we came here to look for them at Banff National Park.
It didn't take long before we found the first group.
Those little white butts over there are bighorn sheep.
They're so cute.
Looks like this herd is made up of at least 50 sheep,
but only one of them seems to be an adult male.
You can tell by those horns.
The males are the ones with the big horns that roll all
the way back around their head and forward again.
But the female's horns are only about 30 centimetres long.
Males are called rams and females are called ewes.
The rams are bigger than the ewes and can get huge.
An average healthy male can get to 150 kilograms,
more than twice as heavy as the average human adult.
Though in the rocky mountains, where we happen to be today,
they can get even larger, with some getting to 250 kilograms, about as heavy as a large black bear.
A big part of that weight is their horns.
They can be up to 10 percent of their body weight.
Combine that with their huge head and powerful neck
and you have one of the most top-heavy animals in the mountains.
So we're happy to see them, but we won't get too close.
Bighorn sheep are extremely social animals, and herds like this are called nursery groups,
usually led by the oldest, most mature ewes, who spend all their time teaching the other females
and their young how to get by as a sheep, finding the best food and the safest passage around.
And there are very good reasons to get along.
Their fights are brutal.
When bighorn's butt heads the earth trembles.
During the rut, rams battle for social status.
When they see the battle is on, they'll walk away from each other,
like Alexander Hamilton and William Burr, and then turn around and charge each other.
It's a real western showdown.
Rams can sprint at 35 kilometres an hour, and the collision between two large rams
can have the same force as a motorcycle hitting a wall at 70 kilometres an hour.
And all of that force gets funnelled into the tip of the spear, their horns.
A ram's horns grow continuously throughout their entire lives,
slowing down during the winter and speeding up in the summer, when food is more available.
This creates rings called annuli.
You can actually determine the age of a ram
according to how many annuli you see on those horns.
This isn't survivable for humans.
So how do rams get away with hitting their heads repeatedly
without having their skulls and brains turned into dust?
Bighorn sheep have a series of adaptations to protect
themselves from the long-term effects of repeated head trauma.
The first one is their horns, which are made of keratin and a bony core.
The keratin, the same material as your nails,
is more flexible than bone and absorbs some of the impact.
The skull itself is also very thick and resistant to fractures.
But the most important part is their brain.
This is because upon impact, the brain hits the inside of the brain cavity.
But bighorns prevent their brain from sloshing around with two main adaptations.
The first one is their brains are slightly more snuggly fit into their brain cavity,
so there's slightly less shaking around.
The second, and most important one is that before the moment of impact
they send extra blood to the brain.
This slightly inflates the blood vessels of the brain,
creating something like bubble wrap to protect it even further.
When they're not fighting, they're usually grazing as a group.
These ungulates occupy a huge range and their diet adapts to their environments.
Grasses are an essential part of their diet in the northern part of their range, whereas in the dry
hills of Mexico, they might resort to eating cacti or whatever they can find on the hills.
Bighorn sheep are amazing climbers and are super well adapted to this rocky terrain.
Their hooves are two-toed and they have the hard exterior made of keratin,
as well as a pad underneath that gives them better grip on those rocks.
One thing to keep in mind, if you want to see them in the wild,
is they're not good at walking in snow.
So in the colder months they live on the eastern slopes of the mountains, which are usually drier.
Predators also have a tougher time hunting in the slopes,
and large rams are seldom targeted, but the young and the weak are often taken by the
who's who of North American predators such as bears, wolves, and eagles.
I don't blame them for not trying to attack groups with multiple rams,
that could punt you into oblivion.
Unfortunately, as we all know by now, living in huge groups has its downsides.
The main one of them is that diseases spread quickly.
Pneumonia is particularly deadly and outbreaks sometimes kill up to 90 percent of a flock.
More recently, a virus has been spreading throughout the Yellowstone bighorn population.
This has caused an increase of an illness called sore mouth disease,
which destroys the soft tissues inside their mouths.
This disease is common among factory-farmed sheep,
and though it's survivable, it can kill lambs and older sheep.
Thankfully, bighorns are protected in large parts of their range and their numbers have bounced up.
There are still causes for concern, such as climate change and habitat destruction, but as
long as we remain vigilant, these massive beauties are going to remain kings and queens of the hills.
So what should I talk about next?
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Thanks for watching, see ya.