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the animal within s02e01
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00:09Within the animal kingdom, the most feared creatures are master hunters, engineered by
00:16Mother Nature to reign at the top of the food chain.
00:20Evolution has equipped these predators to excel in different environments and thrive
00:25in their ecosystems.
00:28Each master hunter is equipped with their own specialized tools to attack and consume
00:34their prey, including spiky legs, glow-in-the-dark eyes, and razor-sharp talons.
00:42Many master hunters have a lot of characteristics in common, including strong jaws, keen eyesight,
00:48and a good sense of smell.
00:50But how have these physical features evolved into surprising and deadly adaptations?
00:57And what can we learn from these highly proficient predators?
01:23On the savannas and grasslands of sub-Saharan Africa, a master hunter works in packs to hunt down
01:31their prey.
01:32There are four known species of hyenas.
01:35There's the brown, the striped, the aardwolf, and then there's the best-known one, the spotted
01:41hyena.
01:42Though they've unfairly earned the reputation of a scavenger, these fearsome carnivores reign
01:48supreme at the top of their food chain.
01:55Hyenas are hugely successful predators, and they're thought to kill up to 90% of their own
02:00food.
02:01It's a common perception that hyenas eat the leftovers of what lions kill, but it's really
02:06the opposite that's true.
02:08Lions are actually more likely to steal from hyenas than the other way around.
02:13Spotted hyenas, also called laughing hyenas, are infamous for their high-pitched, giggle-like
02:20calls used in heated conflicts.
02:22Although, survival in this unforgiving savannah requires much more than a haunting laugh.
02:33The hyenas' prey, which includes wildebeest, gazelle, zebra, and buffalo, are equipped with speed
02:41and deadly defenses like horns, and competition with rival predators like lions is fierce.
02:50So, what makes the spotted hyena so uniquely successful?
02:58Spotted hyenas are equipped with an arsenal of specialized hunting adaptations, starting
03:05with their powerful jaws.
03:07The hyena's amazing adaptation really is its bite, its ability to crush bone.
03:14Their huge strength in their jaw is really analogous to a car crusher, you know, where we put
03:20a car in a big hydraulic press and press it down to nothing.
03:23That's what the jaw is doing.
03:25But force alone isn't what's going to make them able to crush bone.
03:30You need to apply that force to a very small area.
03:35Hyenas have pyramid-shaped premolars, and that gives us a concentration of force like
03:41you would have at the tip of a jackhammer.
03:43They are able to bite into bones, which most animals can't do.
03:48And it means that they can access the energy-rich marrow within those bones, this incredibly rich
03:53resource that is thought to have more energy than meat itself.
03:58But it's not just their teeth and muscles that make their bite so powerful.
04:04Their skulls are uniquely formed to maximize the power of their jaws.
04:09A sagittal crest is a ridge on the top of the skull.
04:13Having a sagittal crest allows for more muscle attachment and allows the jaw muscles to have
04:19more leverage to have a stronger bite.
04:23Hyenas take this design one step further.
04:26The sagittal crest on their head contains hollow, air-filled chambers.
04:31These chambers reinforce the crest and allow it to distribute the bone-crushing force from the animal's bite.
04:39As engineers, when we design structures to hold immense forces, we look to triangular shapes.
04:47Triangular structures, they're self-bracing.
04:51When you apply a load to a triangular structure, it does not want to collapse.
04:56Hyenas use these triangular structures in their jaw to allow them to apply these huge forces without their skull collapsing.
05:06Powerful teeth aren't any use if you can't find or catch your prey.
05:11And the spotted hyena is superbly engineered to accomplish both tasks.
05:17Hyenas have an extra large olfactory surface inside its nose.
05:21They can detect the scent of prey or carrion at a distance of up to four kilometers.
05:27Hyenas also have excellent hearing.
05:29They can detect other hyenas calling from up to five kilometers away.
05:35To make use of these sensory tools, hyenas often hunt in the cover of darkness.
05:41They can easily tackle small prey alone, but form deadly packs of up to 30 when stalking a larger meal.
05:52When hyenas go to hunt, they do something called test chasing,
05:55where they check to see how fast and healthy potential prey is before they commit to actually going in for
06:01the kill.
06:03Hyenas don't stalk their prey like lions do.
06:05They're endurance hunters, which means they chase after their prey and run them down until they're exhausted.
06:13So, how do they manage to outlast some of the speediest animals on the savannah?
06:19Their hind legs are shorter than their front legs, and this gives them a loping gait, which is quite an
06:24energy efficient form of locomotion.
06:27And the inner workings of this animal are equally as impressive.
06:32Hyenas have a big heart, big lungs and wide nostrils, and this helps them get lots of oxygen into their
06:38bodies.
06:39It's like putting a V8 engine and a big gas tank in a Honda Civic.
06:43It's great for both speed and for stamina.
06:48Hyenas will chase their prey at high speeds, up to 60 kilometers per hour, for as many as 5 kilometers.
06:56When their quarry is too exhausted to run further, a single hyena will bring them down with a vice-like
07:02bite to the leg,
07:03allowing the rest of the pack to move in.
07:07Once their prey is down, hyenas rely on some of their other unique adaptations.
07:14If you have an animal that's been running for minutes on end, it starts becoming a thermodynamic problem.
07:21The body tends to build up a huge amount of heat.
07:23You're expending a lot of energy, and the net output of energy is always heat.
07:29Hyenas use a huge number of blood vessels in their snout.
07:34Basically, by having these blood vessels near the surface and expelling air as they breathe in and out over those
07:41blood vessels,
07:42it cools the hyena.
07:44This is very analogous to a radiator.
07:46Radiators have very small channels through which coolant flows,
07:50and then air is blown through the radiator to extract the heat from those small channels of liquid.
07:58And hyenas have other adaptations that help them make quick work of fresh kills.
08:05Hyenas don't have retractable claws, but they do have large paws,
08:08which helps hold down the carcass so they can tear at it and pull off the meat and eat it.
08:13The hyenas literally often are forced to move carcasses around.
08:17Now, if we're talking about a zebra carcass, it can weigh 50, 100 kilos or more.
08:23For a hyena to be able to drag that, it needs some evolutionary advantage.
08:29When you look at a hyena, you'll note that it has a very long, strong neck, strong shoulders, and a
08:35very bulky body.
08:36It's this long neck that almost acts like a crane and the bulky body of the hyena that kind of
08:44acts as the heavy crane base that allows the hyena to drag very heavy carcasses.
08:50After a kill, it's the alpha female who feasts first.
08:55She'll claim the best meat before passing the dish to her female relatives, while the males and cubs await the
09:02scraps.
09:03In this matriarchy, Rank decides who eats well and who goes hungry.
09:10Hyenas have incredibly complex social dynamics.
09:14Females are always the dominant figures within these social hierarchies.
09:19And males come in, but they have to be subordinate to the females as they enter these social groups.
09:24A higher social status female within the social group will have more offspring and more successful offspring than a female
09:33that is lower on the social hierarchy.
09:36Regardless of their status, however, each member of this social group has an equally voracious appetite.
09:44Adult hyenas can devour as much as 15 kilograms of meat in a single meal.
09:49That's a quarter of their body weight.
09:51And they have the remarkable ability to digest nearly everything that they eat.
09:56They have stomachs with lots of hydrochloric acid and a low pH, which means they can digest more parts of
10:03the animal than many other types of mammals.
10:06The parts of the animal that a hyena can't digest will be regurgitated in a little pellet filled with hair
10:13and hooves and horns.
10:16These powerful stomachs let them safely devour even the foulest disease-ridden carcasses.
10:23And if rivals dare approach before they're done, these fierce creatures won't hesitate to fight tooth and claw to defend
10:31their hard-earned meal.
10:38If a lion does start to bother a hyena while it's eating its prey, they have this whooping sound that
10:44they make that can be heard from five kilometers around.
10:47And they can call in all their friends to help them defend the prey that they've captured.
10:54When we think of the savannah, I think lions have way better PR, but hyenas are actually these well-adapted
11:02little machines that are master hunters in these savannah environments.
11:06While hyenas rule the open plains of Africa with brute force, another hunter commands the skies on the other side
11:15of the world.
11:18Here, supremacy isn't claimed through numbers or crushing jaws, but through aerial speed and razor-sharp vision.
11:28Bald eagles are these killing machines.
11:33They're enormous. They have these knife-like talons. Their beaks are great at shredding prey apart.
11:40These are terrifying killers.
11:45Dominating the skies across North America, ranging all the way from the boreal forests of Canada down to northern Mexico,
11:54the bald eagle often finds its home in coastal areas.
11:59But what does it take to rule these lands? And how does the bald eagle remain perched at the top
12:05of the food chain?
12:10For the carnivorous bald eagle, it means hunting everything from rodents to turtles, small mammals, and even other birds.
12:19However, there is one prize that truly fuels their reign.
12:24Fish, which makes up a staggering 65% of their diet.
12:32But how do these majestic predators spot prey that lives beneath the water?
12:39Eagles' eyes are so big that they fill up most of their skull.
12:43Their retinas are very densely coated in light-detecting cells.
12:47The light-detecting cells in the eagle's eye allow eagles to see colors much more vividly and have an incredible
12:56ability to observe shades that other animals cannot.
13:00Eagles actually see in ultraviolet.
13:02And this can be a real advantage because some animals will actually glow and be more visible to the eagle
13:09in the ultraviolet spectrum.
13:11This allows them to see prey like catfish and shellfish that are below the waterline.
13:18They can see about two miles away so they can identify prey that's really, really far away.
13:25Hidden behind the eagle's piercing gaze is a convex pit called a fovea.
13:32Scientists believe this acts as a built-in telephoto lens, magnifying objects in the bird's central field of view.
13:41On top of this, bald eagles gain a hunter's edge with a unique ability to switch between monocular and binocular
13:49vision.
13:51Binocular vision allows us to see depth.
13:54This is really important in hunting because you don't want to smash into the ground, you don't want to come
13:59up short and miss the prey.
14:01But we lose a little bit of visual acuity and field of view when you use binocular vision.
14:07Monocular vision allows a much larger field of view.
14:11When an eagle's soaring and hunting, it wants to scan a very large area to look for prey, and that's
14:17where monocular vision is an advantage.
14:20This gives them an impressive 340 degree field of view.
14:26But locating is only the first step of a successful hunt.
14:33Once they've honed in on potential prey, the eagle will have to deploy its knife-like talons to secure their
14:40meal.
14:41The bald eagle's sharp talons are used to hunt, capture and eat their prey, and they have 4 talons on
14:47each foot.
14:48Their feet have 3 toes facing forwards and 1 toe facing backwards, and the toe that's facing backwards has a
14:55very long, hooked claw called the hallux.
14:59Bald eagle's talons are incredible feats of engineering.
15:03The talons have evolved over 36 million years into the perfect hunting tools,
15:09able to grab, stab and crush with incredible strength and precision.
15:14The bald eagle catches prey by sweeping low and snatching them up in their talons.
15:23Unlike other predatory birds like falcons that plummet from the sky in high-speed dives,
15:29the eagle's hunting style is a dramatic low-flying ambush that turns stealth and strength into a deadly combination.
15:41Once its slippery catch is secured within its grasp, how does a hungry eagle get its meal from the water
15:48to the skies?
15:50Bald eagles have these bumps all over the palms of their talons so that they're able to better grip slippery
15:57prey.
15:59It uses its powerful bumpy grip to hold on to its catch, with a pressing power of up to 1
16:05,000 pounds per square inch.
16:08Potentially the strongest of all birds of prey.
16:13Eagles are extremely strong, and they can carry up to half their body weight.
16:17Like power lifters in the air, these birds are often capable of carrying prey that weighs up to six kilograms.
16:28However, hauling in such a rich feast requires more than raw muscle.
16:34Fish and rabbits can zip through their environments with impressive speed.
16:38Luckily, the bald eagle is built for the chase, clocking above average soaring speeds of nearly 50 kilometers per hour.
16:49Bald eagles fly much faster than most of their prey.
16:53Atlantic herring only swim at about 4 kilometers per hour.
16:58Mice only run at about 13 kilometers per hour.
17:02These animals don't even stand a chance.
17:06Evolution has sculpted the bald eagle into a marvel of aerial engineering.
17:12At the heart of its power lies a large keel of bone that anchors two pectoral muscles.
17:19This is connected to a network of hollow, lightweight bones, allowing it to flap and glide with minimal resistance, similar
17:28to the keel of a ship.
17:29The keel of the ship is the part that all the other parts of the ship attach to, so it
17:35has to be very strong and hold the whole structure together.
17:40Adding to this ingenious structure is a remarkably impressive wingspan.
17:47The eagle's wingspan is about 2.3 meters in length, which is taller than most humans.
17:54I mean, this is really a massive wingspan.
17:57When they want to fly really fast, they can actually reach speeds of up to 120 kilometers per hour.
18:04That's as fast as cars driving on the freeway.
18:08In the bald eagle's case, the bigger the wings, the smoother the flight.
18:13Their superior wingspan generates a tremendous amount of lift, carrying the bird to breathtaking heights.
18:20Their broad wings also minimize drag as they slice through the air.
18:26Even turbulence, the invisible potholes of pressure in the sky, is reduced by their reach.
18:35Interestingly, it's these aerodynamic features that have inspired engineers in the design and construction of airplanes.
18:44When we think about how wings work, the surface area of the wing is really important to efficiency.
18:52Small wings don't generate a lot of lift, so you have to flap your wings very quickly.
18:57With large wings, you get a lot more lift and therefore can soar and stay in the air without expending
19:04a lot of energy.
19:07Today, many airplanes are designed with long, wide wings, just like the soaring bald eagle.
19:15By increasing the wingspan and surface area, aircraft can reach greater heights with less effort,
19:21making them more sustainable and fuel efficient during flight.
19:29For the eagle, this steady glide above the Earth is more than a display of power.
19:35It's the ultimate vantage point.
19:38From here, it can scan the landscape, zero in on prey and launch a deadly attack with precision.
19:47Then, it's time to dig in.
19:50An eagle obviously can't swallow its prey whole. It has to cut it up into smaller pieces.
19:56So, the way the eagle does that is it holds the prey with its talons and tears with its beak.
20:02Its beak is very large and very strong and very sharp, kind of analogous to a hunting knife.
20:08And that really allows the eagle to tear its prey into smaller, more manageable pieces that it can swallow.
20:15Yet, even among this dominant class of apex avians, there exists a pecking order.
20:22Much like the matriarchs of the hyena clans, it's the female bald eagles who rule supreme in size and strength.
20:33The female is actually larger than the male.
20:35And because she's bigger than the male, it means they can hunt slightly different types of prey.
20:41This reduces competition for prey.
20:44It makes them more efficient hunters.
20:49Though not every hunt results in success.
20:53Even the most skilled bald eagle requires a backup plan.
20:58And in the face of failure, these birds are forced to adapt their strategy.
21:04When we think about eagles, we think of them as being very regal.
21:08But in reality, they're often scavengers.
21:11They'll fly to rivers and eat dead salmon or eat dead carcasses.
21:16So they're actually closer to vultures than the apex predators that we think they are.
21:22When food is scarce, bald eagles turn to pirate-like tactics, stealing food from other birds.
21:31They stand watch from a perch, using their eagle eyes to identify when someone else has food.
21:42Then, with a burst of speed, bald eagles swoop in to intimidate their victims and seize their bounty for themselves.
21:53If a lower-ranking bald eagle catches a great item of prey, it's not unheard of that a higher-ranking
22:01bald eagle will grab and steal that food from the other individual.
22:10But for less territorial eagles, teamwork becomes the ultimate tool, opting to hunt in pairs or groups to secure a
22:19shared feast.
22:21These animals come together so that everybody gets at least a little bit of food.
22:25And it means that you have two sets of these eagle eyes looking out for that prey item.
22:34And two sets of eyes are going to be better than one.
22:38Bald eagles are supreme master hunters.
22:43While these ultra-efficient hunters strike terror from above, an entirely different kind of predator rules the small jungles of
22:52the insect world with stealth.
22:55And a lightning-fast strike that is just as impressive.
23:02A praying mantis might look like an elegant dancer in the environment that it lives in.
23:10But it's actually a finely-tuned killing machine.
23:13They are vicious.
23:17Like all insects, the praying mantis has six legs and is made up of a head, a thorax and abdomen.
23:24But they are also equipped with unique features that set them apart as a predator unlike any other.
23:32It's incredibly stealthy, it's very well camouflaged, it can sneak up really close to its prey, and when it strikes,
23:40it's incredibly precise and fast.
23:43All these features combine to make the praying mantis an undisputed master hunter.
23:51Over 2,000 species of this feisty insect have evolved and currently exist.
23:58Most species thrive in humid tropical rainforests.
24:01But this adaptive predator can also be found stalking prey in the grasslands, meadowlands, and even in the harsh desert
24:10heat.
24:14A true carnivore, the praying mantis feeds exclusively on live prey.
24:20Often snatching up moths, flies, grasshoppers, and crickets.
24:27But with a voracious appetite, nothing is off the menu.
24:32These fearless insects have also been known to take down animals several times their size.
24:40A praying mantis will try to eat anything that looks like food.
24:44And so sometimes they'll end up with weird food resources like a tiny little lizard or a worm.
24:53In fact, some of these opportunistic insects are well known for going rogue on their own mates.
25:01The praying mantis is famous for eating its mate after they copulate.
25:08This isn't unusual in invertebrates.
25:11There's lots of spiders that do this as well.
25:13And the reason the female eats the male is because that is a food resource that means that she can
25:19then have more babies.
25:21They're not more brutal with her mates than they are with other things.
25:25They're just having a snack.
25:28But how exactly does it master this rapid sneak attack?
25:32It all links back to the engineering of their five eyes.
25:38The mantis' main eyes have about 10,000 lenses.
25:43These mini eyes wrap around the mantis' head, providing a panoramic view to track unsuspecting prey.
25:51The overlap between its right and left eyes also creates binocular vision, giving this tiny hunter the depth precision needed
26:00for a perfectly timed strike.
26:05Essentially, a mantis can very quickly see everything that's around it and really notice any movement that may be associated
26:13with prey in that huge field of view.
26:18Hidden behind the powerful main eyes are three smaller eyes designed to detect shifts in motion and light.
26:26Praying mantis can detect movement up to 18 meters away, and that's part of what makes them such successful hunters.
26:33The praying mantis' exceptional camera-like eyes have inspired researchers at the University of Virginia to develop cutting-edge artificial
26:42vision for use in machines.
26:45These researchers created a semi-circle sensor, the same shape as a praying mantis' eye.
26:52Within the semi-circle are micro-lenses that produce an electric current when exposed to light.
26:59This allows the sensors to detect motion and colors while focusing on multiple objects at once.
27:07Applying compound lenses to autonomous vehicles really allows us to see a larger part of our environment.
27:17But with so many insects darting quickly out of reach, the praying mantis needs more than sharp eyes to keep
27:24its prey in sight.
27:26That's where its remarkably flexible neck comes in.
27:30A praying mantis is able to rotate its head a full 180 degrees. That's more than any other insect species.
27:38The praying mantis has a flexible joint between its head and thorax, which is what allows them to swivel their
27:45head.
27:47The 180 degrees of motion allows them to stay perfectly still with the rest of their body while keeping an
27:54eye on potential prey.
27:55Once locked in, absolute stillness is the praying mantis' greatest tactic.
28:04Masterfully camouflaged among leaves and branches, the mantis waits in silent ambush.
28:13A stealth so skilled that its prey remains oblivious until it's too late.
28:24Prey mantises are naturally camouflaged.
28:27They're typically brown or green, which allows them to blend into their surroundings of trees and leaves.
28:33Some have even evolved to look like flowers.
28:36Some mantises are such masters of camouflage, they are named after the object they are mimicking.
28:42The orchid mantis looks just like a flower.
28:46It's white and pink and its limbs even look like petals.
28:50It is a very efficient hunting strategy.
28:53You wait for your prey to come to you.
28:58The problem is, many insects, including its prey, are masters of camouflage themselves.
29:05So, how does the mantis detect a meal that's hidden in plain sight?
29:11A special ear in a strange spot.
29:16A mantis' ear is located between its hind legs, which is a particularly unusual place to have an ear for
29:22an insect.
29:22This single ear provides the praying mantis with ultrasonic hearing to help them identify prey.
29:30Their ultrasonic hearing means that the praying mantis can pick up extremely high frequencies.
29:35For example, they can hear the sound of a tiny insect's wings beating.
29:39Once it's been identified, the camouflage praying mantis will creep towards its prey to get within striking distance.
29:46And when needed, they can kick their legs into high gear.
29:51Mantis' have six joints on their middle and hind legs and four joints on their front.
29:57When we think about joints in limbs as engineers, we call those joints degrees of freedom.
30:03The large number of joints in the mantis' legs and arms gives them a huge amount of degrees of freedom
30:10of movement.
30:10And in robotics, we try to do the same thing.
30:13Give our joints as many degrees as freedom as possible so our robots can get to where we need them.
30:19Once in a suitable distance to strike, the praying mantis assumes its famous position.
30:26Early naturalists thought they looked like these insects were praying and so that's where they get their name from.
30:33Then, in a sudden flash, their front legs strike out and capture their meal.
30:41When they strike at prey, they are faster than the blink of an eye.
30:46Its front legs work together like a set of spring-loaded traps.
30:51Made up of four segments, the tibia, femur, coxa, and trochanter, these legs are lined with sharp spikes, allowing the
31:01mantis to impale their prey and hold onto it while chowing down.
31:07They also tend to immobilize their prey after they've impaled them by biting their necks.
31:14But their spiky legs aren't only used for attacking and feeding. They are also used for jumping.
31:22They can launch themselves one to two times the length of their body and reach their designated targets in less
31:27than a tenth of a second.
31:29The mantis gets into jumping position using the following motions.
31:33It shakes its head from side to side, scanning the path towards its target.
31:38It rocks backwards to curl up or tuck in its abdomen.
31:42Then it pushes its legs to initiate the jump.
31:45When a mantis leaps to kill its prey, its prey will probably move, so the mantis has to adjust mid
31:52-flight.
31:53The mantis has the amazing ability to independently twist the front and back ends of its body,
32:00so the front end can stay oriented on the prey while the back end makes adjustments to the angular momentum.
32:09What happens once the mantis finally snags its unsuspecting prey?
32:14That's when this hunter unveils its next lethal adaptation.
32:20True bugs actually have a pointy, piercing mouth part, and then they suck out the goo inside other insects.
32:27But a praying mantis actually rips into the exoskeleton.
32:31And many, many other invertebrate predators cannot do that very easily.
32:34With this incredible arsenal, the praying mantis savors the spoils of yet another ambush under the cover of leaves.
32:44Meanwhile, another fearsome predator wields its power in the vast open wilderness of the north.
32:52This omnivorous powerhouse is equipped with adaptations that give it the upper hand,
32:58whether it's hunting prey or foraging for plants.
33:02In the untamed wilderness, few creatures can rival the grizzly, and all are at risk of becoming its next meal.
33:13Grizzly bears will eat anything.
33:16They eat roots that they dig up.
33:17They eat berries that they find.
33:20They eat insects, rodents.
33:23They will eat fish, moose.
33:26They'll even eat each other.
33:28They'll eat other bears if they can.
33:31But before they can fill their bellies, they first have to hunt down their fuel.
33:36How do they do this?
33:38It all starts with the incredible organ at the end of its snout.
33:44Grizzly bears are thought to have the best sense of smell of all mammals.
33:49This is due to their giant nasal mucosa.
33:53The nasal mucosa is the area inside a grizzly bear's nose, which is 100 times larger than a human's.
34:02A grizzly bear's nasal mucosa is covered in a honeycomb-like structure covered in millions of sensory receptors.
34:10These receptors detect scents in the environment and they transmit information to the olfactory bulb where this information is processed.
34:20Grizzly bears have one of the most effective olfactory bulbs in the world.
34:25Grizzlies can track their prey by smell for up to 32 kilometers.
34:32Grizzlies can also smell their prey underground.
34:35One of the main prey species that they prey upon are rodents, and rodents build their burrows up to 2
34:41meters underground.
34:44But once this delicious snack has been located, how exactly does this massive bear access a tiny, well-protected burrow
34:52deep below the earth?
34:54For this, it relies on the sharpened claws at the end of its large feet.
35:01Grizzly's claws are made of keratin.
35:04Keratin is a structural protein that makes up things like nails and hair and hooves.
35:09It's a naturally occurring plastic.
35:12It's very strong, it's very flexible, and it's very tough.
35:17Keratin can allow grizzly bears to dig holes with their claws.
35:21It allows them to grow fur so that they're warm.
35:25So a lot of the amazing innovations in vertebrates center around our ability to grow this natural plastic called keratin.
35:36A fully grown grizzly bear's front claws can reach lengths of up to 10 centimeters and can be used like
35:44Swiss army knives.
35:45These key hunting tools allow this master hunter to skin fish or even dig up the underground burrows of rodents.
35:55The grizzly bear's claws are a lot like excavators and big construction projects.
35:59It allows them to dig underground and pull up the things that they find.
36:05Powering this excavation is a network of muscles that converge under a large distinctive hump on their back.
36:14They have these massive shoulder humps, and those humps include shoulder muscles that are attached to their forearms.
36:21And this gives them an incredible amount of strength for digging.
36:26Substantial shoulder humps provide the grizzly bear with an extra boost of strength and power in their forelimbs.
36:32Not just for digging, but for chasing down food at incredible speeds.
36:39Grizzly bears are capable of running up to 45 kilometers per hour over extended distances.
36:45That's the same speed that deers run.
36:49Unsurprisingly, grizzly bears also eat deer.
36:52How does this massive mammal sustain the speed of a much lighter fleeting deer?
36:57The secret lies in the bear's skeletal structure.
37:01Yeah.
37:01To go along with these really big muscles, grizzly bears also have really stout bones.
37:07From its scapula and its humerus, these bones are built in a very strong way to support these really strong
37:14forces that its muscles create.
37:18This living machine is engineered for maximum force.
37:23Each stride is a surge of raw strength, propelling the bear forward in each high-stakes pursuit.
37:30And regardless of their catch, rest assured their robust jaw and teeth will help break it down.
37:39A grizzly bear has 42 teeth, the same as a dog or a wolf.
37:43These powerful jaws generate an impressive bite force of 1160 pounds per square inch.
37:52While the average human bite force is a mere 162 pounds per square inch.
37:58It uses its pointy canines to defend itself or to catch salmon.
38:07For this hungry opportunist, the landscape reads like a varied menu.
38:12But there's one snack that grizzlies favour above all.
38:16Salmon.
38:18Before they hibernate, grizzly bears will eat an incredible amount of salmon.
38:23And once they get full, they actually will tear off the skin, which is the fattiest part of the animal,
38:28and eat only that to get the highest nutrition possible and not fill up on some of the meat that
38:35has less nutrition in it.
38:38For just two months each year, the rivers team with spawning salmon.
38:43And the grizzlies waste no time in seizing this rare opportunity.
38:49They consume huge quantities of salmon, up to 30 salmon a day.
38:55But how does a single bear rake in such a massive hole?
39:00One of the most common strategies for grizzlies to catch salmon is what's called the stand and wait technique.
39:06This is where they stand at the top of a waterfall, and they'll wait until salmon try and jump up
39:12that waterfall,
39:12and then they try and snatch them out of the air.
39:16Grizzlies will also perform what's called a sit and wait technique,
39:19where they feel under the water and try and find a salmon,
39:23and then pin it to the bottom and try and pull it out of the water with their claws.
39:29The sit and wait, however, requires some patience.
39:33And not all bears have the temperament for such a calm approach.
39:36For the go-getters, another method might be more suitable.
39:41Another method is the dash and grab, and this is where they combine their sense of sight, smell,
39:47and their impressive running speed to chase down the salmon in the river.
39:52However, this method burns a lot of energy,
39:55and is usually only used near the end of the salmon spawning season.
39:59A last-ditch effort to consume as many calories as possible.
40:05This is like filling up the gas tank at an overpriced gas station,
40:09when you really need to fill the tank, but it costs a lot more to do so.
40:14After this massive consumption of calories comes hibernation.
40:22Grizzly bears hibernate from four to seven months a year, depending on their location.
40:28Hibernation is a state where the animal reduces its metabolism,
40:33until better conditions where food is more available.
40:38While it's widely known that grizzly bears hibernate,
40:41the way their bodies are designed for this dormancy period may come as a shock.
40:47Ahead of hibernation, adult grizzly bears can eat for 20 hours straight,
40:51and consume an amazing 100,000 calories per day.
40:56This massive calorie consumption is called hyperphagia,
40:59and this is really their last-ditch effort to take in as many calories as they can ahead of their
41:05hibernation.
41:08But how can these bears consume such grand amounts of food without feeling full, or worse, getting sick?
41:17The trick is in the unique function of their pancreas.
41:21The pancreas produces digestive enzymes, and those digestive enzymes are released into the small intestine,
41:28and they help break down the food.
41:30But the pancreas also produces a hormone called insulin.
41:34And insulin is a really important hormone to regulate our glucose levels in our blood.
41:41Grizzlies' resistance to insulin adapts to their life cycle.
41:46During the hyperphagia period, their bodies are most sensitive to insulin,
41:50and turn the mass amounts of fuel they're consuming directly into fat instead of sugar.
41:57This provides them with a more substantial energy source.
42:01During hibernation, grizzly's sensitivity to insulin totally changes.
42:06In this period, grizzly bears don't want to be storing fat.
42:10They want to be using fat.
42:11So they turn off their sensitivity to insulin so they can use those fat resources
42:16that they built up in the earlier hyperphagia period.
42:20But even though there's a significant slowdown,
42:23the grizzly bear still burns up to 4,000 calories a day during this dormancy period.
42:30That's why it's so critical for grizzly bears to use their master hunter abilities to bulk up for the winter.
42:36If they don't, and they don't take in enough calories, it's game over.
42:43And when the long, cold winter is finally over, the grizzly bear emerges,
42:49well-equipped to start the hunting season all over again.
42:56But while some animals take a well-deserved rest, other predators never stop.
43:03Through blizzards and bitter cold, one hunter has been prowling the wilderness all winter long.
43:10The grey wolf, one of the most refined and relentless carnivores in the wild.
43:18So, how exactly did they earn this title?
43:24While this canine boasts a number of biological advantages,
43:28its true superpower is its tendency to hunt in packs.
43:35Hunting effectively in packs takes a high level of sophistication.
43:40Wolves are highly organized creatures, and each pack follows a strict formation, determined by the number of members.
43:52Traditional understanding of wolf packs observed in captivity showed rigid hierarchies,
43:57where an alpha role emerged over beta and omega wolves.
44:01But our modern understanding is that wild packs are actually families.
44:05The alpha pair are simply parents, while betas and amigas are their offspring,
44:10participating in social cooperation through parental leadership.
44:13Not pure aggression.
44:15But what determines their place in the pack?
44:17And who gets to call the shots?
44:20When researchers observe wolf packs, they can often tell who the alpha is,
44:25because the alpha will curl their lips.
44:29And also have a tail that sits straight up, in a very dominant position, very confident.
44:36When the alpha is ready, he gives the signal,
44:40and his pack members react to his commands.
44:43When hunting larger animals, like bison, the pack will surround the animal.
44:49And then individuals will run in, and bite them on the shoulders, and bite them on the flank.
44:57Grey wolves' hunting formations are so effective, that they inspire the invention of a high-tech algorithm.
45:04Grey wolf optimization.
45:07When we think about how to build systems of robots together to achieve a goal,
45:14we start thinking about that pack mentality, where each member of that swarm will have a different role to fulfill.
45:21And that's very analogous to what's happening in a wolf pack, with the different members fulfilling different needs for the
45:28pack.
45:29Wolves are endurance hunters, which means that they don't have to be faster than their prey over short distances,
45:35but they do have to keep going.
45:43They essentially exhaust their prey until they can't run away anymore.
45:47And when they're pursuing prey, they can travel up to 70 kilometers a day.
45:54They have huge hearts, and huge lungs, in order to get enough oxygen to their muscles,
46:00so that they can go these long distances.
46:02On top of all of that, they have to get rid of heat.
46:06Wolves do that through their tongues, through their breath.
46:09They're expelling all of this heat.
46:12They are the marathon runners of the animal kingdom.
46:17The grey wolf has been perfectly engineered for a persistent hunt.
46:22Their lean, muscular bodies are attached to long, powerful legs,
46:27providing a combination of speed, stamina, and strength.
46:33Grey wolves are equipped with narrow chests and outward-splaying forelegs.
46:38What this allows them to do is move their forelimbs and their hind limbs in the same track,
46:43so they can cover more distance.
46:45Their padded feet enable them to grip complex surfaces like logs and rocks.
46:51And this is really important on long hunts when they're chasing after elk and caribou.
46:57Out in the wild, however, competition for food is fierce,
47:02with much larger predators patrolling the same territory.
47:06Luckily, these canines are incredibly resourceful.
47:15To give themselves an edge over their rivals, wolves do the majority of their hunting under the cover of darkness,
47:22relying on a unique feature to capture their meals.
47:26When you see pictures of wolves and other predators taken at night time,
47:31you'll often see these huge, glowy eyes staring back at you.
47:37This almost supernatural stare is the result of the tapetum lucidum,
47:43a mirror-like layer of cells behind their retinas.
47:47When light comes into the eye, it goes past the sensors,
47:51and some of the light is picked up by the sensors,
47:53and the remaining light passes past and is reflected back to the sensors,
47:58where it has the opportunity again to be sensed, increasing the sensitivity of the eye.
48:05And sight is only half the story.
48:08The wolf's head also houses an incredible acoustic weapon, their ears.
48:14Their ears are shaped like triangles, and they can actually turn independently of one another.
48:20And that's really useful because it means that they can pinpoint sound from various different directions.
48:26These specialized receivers contain a network of finely tuned instruments.
48:31Most importantly, a cochlea.
48:35The more coils of the cochlea, the better the hearing.
48:38A wolf has three and a half turns in its cochlea.
48:42This is more than most of its prey, which only have two and a half.
48:46This allows the wolf to hear their prey way before their prey can hear them.
48:54Once the gray wolf's prey is in an optimal position, the entire pack launches into attack mode,
49:02using one of their most powerful tools to slash at the hide of their prey.
49:08Their teeth.
49:09The incisors and canines are the primary tools the wolves use when they're on the hunt.
49:15Their canines can pierce flesh, and then the incisors are used to cut it.
49:21Anchored by strong neck muscles, their bone-crushing bite holds firm,
49:26even as the prey drags them in a desperate struggle.
49:31A full-grown elk weighs two to three times the mass of a gray wolf.
49:36A full-grown bison weighs five to ten times that mass.
49:40The fact that gray wolves can take down prey that are so much bigger than they are
49:44really emphasizes what great hunters they are.
49:49And preying on such enormous creatures provides the gray wolf with more bang for their buck.
49:55When food is abundant and the pack makes a large kill,
49:58gray wolves are known to consume as much as 10 kilograms of meat from their prey.
50:06But when a pack isn't so lucky, or when food is scarce,
50:11they're also engineered to fast for months at a time,
50:15living a true feast or famine existence.
50:21Their metabolism is very adaptable,
50:23so they're able to store large amounts of fat when food is plentiful,
50:27and then use that fat during periods when food isn't available and they need to fast.
50:33But what happens if the attacker becomes the attacked?
50:39When a single miscalculation against a thousand-pound bison could mean instant death?
50:46It's always risky for wolves to take down a large prey item because those animals have great kicks,
50:54they might have horns, they have hooves, and they are at risk of serious injury or even a lethal blow.
51:01The wolf knows as well as any predator that out here in the unforgiving wild,
51:07every risk is definitely worth the reward.
51:11Given all the challenges that gray wolves face,
51:14often living in extreme environments, hunting prey that are much bigger than they are,
51:19sometimes very dangerous,
51:21these animals deserve the recognition for being a master hunter.
51:26Whether it's in the tundra, rainforest, grasslands, or in the desert,
51:33master hunters are located all over the world, equipped with tools to kill.
52:06It's very high to the
52:08You
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