Wildlife Predators: Crocodiles, Alligators, Caimans & Gharials | Free Documentary Nature

[Music] the animal kingdom a remarkable array of living breathing natural wonders [Music] compelling ingenious [Music] and extraordinary fascinating physical visceral and ferocious [Music] discover their past present and future just stunning just glorious just amazing [Music] just crocodiles apex predator primeval beast robust survivors they might induce fear but these commanding reptiles also deserve respect and admiration [Music] crocodiles co-existed with dinosaurs and managed to outlast them they might be cold-blooded but they are warm-hearted they are the only reptiles to care for their young known as hatchlings over 20 species of crocodilians can be found lurking in 91 countries mostly in tropical regions [Music] [Music] the american alligator in particular has an abundant population recently estimated at 5 million [Music] all crocodilians share the same characteristic features [Music] long snouts countless teeth [Music] strong jaws powerful tails and tough coats of scaly skin stealth is their standard mode of operation like magicians they can disappear in plain sight water cloaking their long bodies patience is another quality they exhibit one that can be rewarded in an instant [Music] crocodilians are not fussy eaters if it's meat these carnivores are happy on this protein-rich diet they can grow to impressive sizes [Music] the largest in the group is the saltwater crocodile which are commonly nicknamed salties on average the males or bulls can measure over five meters in length weight wise they can get up to a ton female salties or cows only get to half that size lecouvia's dwarf caiman lies at the other extreme of the crocodilian spectrum these petite reptiles weigh between six and seven kilos [Music] regardless of size these ancient creatures are strangely intriguing there is much more to them than what's on the surface [Music] [Music] the word crocodile is often used as a blanket term to describe the various types of reptiles that belong to the crocodilian order which includes alligators or gators caimans garils and crocs [Music] [Music] while they are vastly outnumbered by lizard and snake species crocodilians make up for it by having the three largest reptiles in the world within their ranks like their reptilian cousins crocodiles are cold-blooded vertebrates that come into the world via an egg and have skin protected by scales [Music] these light yet hardy structures are made from a fibrous protein called keratin which is also found in hooves claws and feathers crocs scales are called scutes and are different to those found on snakes and lizards they don't overlap and are set out in regular rows and patterns for added strength many scoots have bony plates called osteodomes growing beneath them the highest concentration of these types of scutes are found along a crocodile's back and neck creating a tough spiky coat of [Music] armor size might vary but overall crocodilians have the same basic appearance long solid bodies laterally compressed tails and drawn out snouts [Music] it is the shape of their snouts that distinguishes gators from crocodiles and alligators is wide and u-shaped with a rounded end while crocs have longer pointier noses like a v another way to tell them apart is to check for any signs of teeth when their mouths are shut gators have an overbite allowing their top teeth to show in comparison crocs teeth interweave giving them a raggedy jawline their grins further enhanced by the fourth tooth on their lower jaw that juts out [Music] each tooth can be replaced up to 50 times throughout their lifetime that's three thousand teeth at a minimum as semi-aquatic creatures swimming is a crocs specialty their muscular flattened tails are like ores powering them through the water webbing between their toes adds to their speed plus helps with steering a saltwater croc can cruise along at 15 kilometers an hour when the mood strikes them they can double that speed for short bursts up on land they're not as agile but do have two styles of walking low and high a high walking croc lifts the trunk of their body off the ground it's a slow gate [Music] to speed things up they can adopt what's called the low walk position where they crawl on their bellies legs splayed out scurrying in a side to side motion the fastest land speed record held by these reptiles to date was set by an australian fresh water croc running at 17 kilometers per hour [Music] being wary of crocodilians in the water and on land is advisable [Music] but looking up can also pay off american gaiters are one of a few species that climb to gain a higher perspective on the world and not just for sunbathing should a meal wander below these daunting reptiles are ready and willing to take the leap the only two continents where crocodilians are not found are antarctica and europe [Music] these reptiles prefer warmer climes and tropical habitats suit their ectothermic needs alligators are however more cold tolerant than the rest of their kind found in higher latitudes where they enjoy milder subtropical conditions 23 species in total crocodilians are a diverse order with 14 members crocodiles are the largest family the leader of the pack is the saltwater [Music] croc [Music] apart from being the biggest they have the widest distribution in the entire order [Music] salties can be found from eastern india down to new guinea and the northern regions of australia some straying as far as new caledonia and fiji the mottled skin of adults can be golden tan in color through to darker grays and black [Music] australia also hosts a species of freshwater crocodile [Music] freshies as they're known locally are much smaller bulls growing to a tenth the size of a male salty in addition fresh waters have longer thinner snouts africa is home to the second largest croc in the world the nile crocodile the average bull weighs 227 kilograms as with all crocodilians female niles are smaller apart from their geographic location one look at a nile's head and neck will distinguish them from a salt water croc niles have a row of scoots behind their head and their snouts are smooth compared to the pair of ridges on a salties the waters of india pakistan and sri lanka are home to the mugger or marsh crocodile these medium large crocks have a broad snout giving them more of an alligator type look the name comes from the hindi language maga meaning water monster the alligator family is next down in size with two species plus half a dozen close cousins known as caimans compared to gators caimans have longer thinner teeth smaller bodies and better agility [Music] of the two alligator species the american is bigger males reaching lengths of 3.4 meters there are thought to be one and a quarter million of them in the southeastern state of florida alone early spanish settlers in the state called them el legato which means the lizard over time the term became anglicized leaving them to be known around the world as alligators the chinese species is less than half the size of its american cohort their stubby snouts are slightly upturned at the end found in eastern china these stout reptiles are known locally as yao long dragons guardials are a single species native to india and nepal the name is derived from the hindu description of the reptile the unusual bulbs on the tip of the gariel's narrow snout look like the traditional earthenware parts of the region known as garas also known as a boss these bulbous growths get larger as the male matures they're thought to be communication tools the buzzing hissing sounds they create helping bulls defend their territory and to attract mates [Music] large or small whatever the species one thing is certain crocodilians are the great survivors [Music] no animal manages to persist for millions of years without having an innovative range of adaptations to see them through for crocodiles this is probably their best it's a brilliant anatomical layout that gives these ambush predators the cunning edge they need with their eyes ears and nostrils placed high on their skulls they can sink and hide their body below the water line while continuing to see hear breathe and smell anything interesting coming their way [Music] [Music] american alligators use their abdominal muscles to alter the position of their lungs within their torso by shifting their center of buoyancy they can control the amount of lift their bodies have as they float [Music] when they do submerge crocs have a few ways to keep water out muscular flaps on their ears and nostrils seal them shut a third eyelid called a nictitating membrane sweeps across to protect their eyes like a pair of natural goggles and when swimming with their mouths open a special palatal valve attached to the back of the tongue stops water flowing into their lungs or stomach thanks to this valve these reptiles can catch prey in or under the water they're busy keeping water out crocodilians also have to keep water in their scoots keep water loss via their skin to a minimum by creating a tight seal the biggest scoots are on their backs directly facing the sun living in warm environments keeping cool is another challenge they face not having sweat glands they get rid of excess heat by simply opening wide gaping like this is similar to panting a cooling effect gained via evaporation from the lining of their mouth taking a closer look at the skin on their head and necks will reveal small bumps or domes these are tiny sensory organs unique to crocodilians they have fingertip sensitivity acting like miniature motion detectors anything causing a ripple in the water will be picked up instantly these domes are also sensitive to temperature and can even detect changes in salinity levels [Music] on land rather than sniffing crocodiles boost their smelling power by gula pumping moving their throats in and out to push scent-laden air into the nasal cavity [Music] the ears of a crocodile are subtle features narrow slits located directly behind their eyes able to function in air and water their hearing has a wide range and is on par sensitivity wise with many mammals and birds crocodiles have excellent night vision an ability they put to good use by primarily hunting at night their prey is often at a disadvantage but crocodilians will eat whenever the opportunity presents itself [Music] during daylight hours that's when their natural camouflage becomes vital dappled patterns and subdued colors allowing them to blend in perfectly with their surroundings the element of surprise is what keeps these beasts fed that and their imposing teeth and jaws they're all about grasping and crushing crocodilian mouths can be stopped with more than a hundred teeth and if broken a new one is ready and waiting in the socket below as for jaw pressure saltwater crocs have the strongest bite on record two times greater than a jaguar the mammal with the most forceful bite and when they snap it's all over in one twentieth of a second crocodilians are not only tough on the outside if they do get injured their immune systems are extremely robust able to ward off infections even in the murkiest waters [Music] to the casual observer crocs might seem lethargic but with the right incentive they can jump into action [Music] on dry ground or in the water they can press their tails and hind feet down and launch themselves [Music] fast frightening and impressive with their knobbly scaly exteriors and primal nature crocodilians seem as ancient as they are they date back 230 million years [Music] crocodilians are one of the two surviving kinds of archosaurs the ancestors of dinosaurs the other modern archosaurs and crocodiles closest living relatives are birds the earliest crocodiles are thought to have evolved from fighter sores similar looking to modern crocs but with nostrils positioned high on their skulls instead of down on the snap tip during the jurassic period approximately 200 million years ago research suggests they became increasingly aquatic possibly in response to competition with terrestrial dinosaurs 100 million years forward in time and enormous crocodilians began to appear one nicknamed supercroc measured 12 meters in length making them twice the size of the largest salty today it seems strange to think a creature covered in feathers that can fly are cousins to crocodiles but on closer inspection the similarities are obvious for instance they both have scales females are oviparous they reproduce by laying eggs their skulls are attached to their spines in the same way on a single point allowing birds and crocodilians to rotate their heads freely nothing moves fast with crocodiles including the rate of change in their genome or genetic makeup of all reptiles alive today crocodiles have changed the least from their prehistoric forebears birds in comparison have advanced at a much faster rate from their common ancestor [Music] in the world of reptiles turtles and tortoises are their closest kin scoots and scales one of a vast range of features shared by these two branches of the reptilian family tree [Music] slow and steady that is how these reptiles pace themselves it's their signature move calm restraint the hallmark of a cunning predator [Music] the nile crocodiles of africa are prime examples they are ambush predators that are patient enough to wait for hours or days for the right moment to strike for prey like all crocodilians they have a powerful bite that can apply enormous downward pressure this along with sharp conical teeth means they can hold their prey with an almost unbreakable grip [Music] able to apply high levels of force for an extended time means they are able to hunt animals much larger in size [Music] the hunt is not always successful but when it is a meal of this size can provide for a crock for weeks while crocodilians are usually solitary creatures they are social to a greater degree than any other reptile [Music] hunting breeding and hatchling care are three important activities that bring them together groups of alligators are known as congregations in the water a gathering of crocodiles is called a float on land a group is referred to as a basque sunning themselves is not a lifestyle choice it's a necessity as cold-blooded animals or ectotherms they rely on external sources to raise their body temperature which in turn raises their activity level the main way they thermo regulate is through their behavior lying around absorbing the sun's heat is a common reptilian practice when they need to cool down crocodilians can mouthgate move into shade or slide into the water aggressive behavior is something crocodilians are known for bulls in particular regularly battle for their place in the local hierarchy and to obtain or guard prime hunting territory [Music] salties do not tolerate others well [Music] they will share areas with females but any male rivals will be chased off their territories are large saltwater bulls sometimes heading out to sea to visit adjoining river systems these lengthy circuits increasing their exposure to potential mates with alligators the largest of both genders will defend their borders smaller gators often form large congregations if they're in the same size range things are relatively peaceful safety in numbers might also be a factor because at this early stage young alligators are vulnerable [Music] aggression levels escalate during the breeding season as crocodilians are polygenous which means males have multiple partners making competition fierce amongst bulls [Music] stance and posture are strong communication tools raising the snout signals submission while at the other end tail arching is a threat display [Music] they do also vocalize [Music] one of the noisiest species is the american alligator males are known to make throaty bellows grunts and hissing sounds the vibrations are thought to scare off intruding males and attract potential mates [Music] in tough times crocodilians can survive when temperatures drop too far they go into brewmation similar to hibernation or if conditions become excessively hot and dry they can dig a burrow in a moist bank and estivate during these periods their heart rate drops from about 40 beats per minute to five if need be they can exist like this for a year [Music] when conditions are good crocodilians can be active during the day but they are primarily nocturnal their eyes hint at this late night behavior the vertical slit-shaped pupils allow their eyes to use what little light is available to their advantage [Music] the only sign of their starlet activity the haunting sight of their red eye shine reflecting back from the darkness bellowing and head slapping that's how some crocodilians announce they're ready to find a mate [Music] roughly a month after breeding females start creating a nest saltwater crocs make theirs above the flood line scraping together wide high mounds of plant material [Music] then they dig out a chamber and lay about 50 eggs they're hard shelled the size of a large chicken egg just heavier the heat generated by the rotting vegetation and the sun incubates the contents of the nest [Music] for two to three months the mothers stand guard [Music] as with other reptiles the temperature of the nest determines the gender of the hatchlings eggs incubated at 32 to 33 degrees celsius hatch out as males nests that are cooler or warmer produce females when the babies are ready to hatch they start to chirp a signal to the mum to start digging them out like baby birds crocodilian hatchlings have an egg tooth on their snouts to help them break out of their shells they drop off after a few days crocodilians have a strong maternal instinct keeping a watchful eye over the babies for a considerable period american alligators guard their youngsters for a year when they first emerge baby gators are 15 to 20 centimeters long saltwater crocodile hatchlings are twice that size hatchlings tend to stick together and close to their mother with her as security the babies work on their swimming skills and learn to feed themselves on whatever fits in their small snouts crustaceans fish and frogs are common menu items [Music] crocodilians are slow growers as adults they might be apex predators but for the first few years these small reptiles are vulnerable [Music] snakes birds and even wild pigs will eat them only one percent are thought to survive to adulthood female salties can start producing clutches of their own when they're about 2.3 metres long it can take them between 10 and 12 years to get to that size juvenile males don't mature into bulls until their 16th birthday with their rugged exteriors and robust immune systems crocodilians are well equipped to survive for lengthy periods [Music] in the wild american alligators can live for 35 to 50 years meanwhile saltwater crocodiles can enjoy seven decades or longer plenty of time to fully explore their lush tropical homes [Music] crocodilians don't need much from their surroundings but they do have two fundamental requirements easy access to water and dry land habitats that are essentially opposites as ectotherms they must have places to haul out and bask [Music] these reptiles also need drier areas to nest and somewhere to shelter from extreme conditions [Music] despite their name saltwater crocodiles can be found patrolling freshwater rivers and creeks plus swamps in addition they can tolerate brackish or slightly salty waterways [Music] they're able to get rid of excess salt from their bodies via a special gland in the tongue [Music] american alligators can deal with salt water for short periods but they're chiefly found in freshwater systems like swamps lakes and ponds as well as streams and [Music] [Applause] rivers [Music] living above and below the water line means crocodilians have two larders at their disposal stalking land-based prey living in the vegetation on or near the water's edge such as mammals snakes and birds plus tasty aquatic life like fish turtles amphibians and invertebrates they are also known to dine on carrion the shape of their snout and their teeth often hint their food preferences sharp needle like teeth and long narrow snouts usually denote fish eaters like garils and freshwater crocodiles a wide snout and blunt teeth help chinese alligators crush their favorite mollusks generalized feeders like salties and gators have features in between these two extremes they could handle any food type they chance upon food is not chewed depending on the size it is either swallowed whole or torn into chunks then gulped down a croc's stomach is highly acidic with levels greater than any other vertebrate a necessity when there are bones hooves and shells to digest like their bird cousins crocs also have a gizzard an organ that breaks down food while birds eat gravel for gizzard stones crocodiles swallow rocks to help grind up their meals [Music] since crocs don't need to waste energy eating their bodies they don't need to eat that often their low metabolism means they can go for months between meals but if something interesting wanders their way they will indulge hungry or not sitting at the top of the food chain these ominous creatures do have an important role to play in their environment [Music] they bring balance by keeping other populations in check the health of the entire ecosystem benefits [Music] their eggs and young are also part of the give and take in the cycle of life as scavengers they dispose of unsanitary carcasses a thankless task they're happy to carry out apix predators and natural janitors two invaluable services carried out by one impressive beast as prehistoric creatures it's not surprising that images of crocodiles have been featured in cultural artworks through the ages [Music] the ancient egyptians feared yet revered these reptiles [Music] their god assigned to watch over the nile was sobek [Music] this crocodile-headed deity was a symbol of strength and power that protected the egyptian people the pharaoh and their army [Music] the southern half of the temple of combo was dedicated to sobek who was also worshipped as a god of fertility and for being a co-creator of the world the maga crocodile plays an important role in hindu mythology as makara the creature that carries varuna the god of the oceans makara is a sanskrit word meaning sea dragon or water monster when anglified this word became maga the common name for the marsh crocodiles of the region makara is also part of hindu astrology being the tenth of 12 symbols in the zodiac equivalent to capricorn [Music] crocodiles also provide transport for ganga the goddess of the river ganges [Music] in central mexico the aztecs had their own sea monster based on crocodiles known as cipatly according to their beliefs the earth came into being after this mythical demon was destroyed [Music] in modern times pakistan holds the maga crocodile in high regard it's their national reptile [Music] crocodiles ancient beasts with a fascinating and full history [Music] [Music] according to recent estimates 51 of countries have a crocodilian of some sort residing in their waterways [Music] of the 23 species that exist however seven are endangered [Music] [Music] like many animals habitat loss is one of the biggest issues they face being apex predators does not grant them immunity at times it exacerbates the problem their natural hunger has made them feared pests [Music] hunting and eradication programs of the past caused population drops in many crocodilian species these losses having a ripple effect down the food chain for example in the amazon basin fish stocks plummeted because caimans were over hunted the nutrient-rich waste materials they deposited in local waterways was no longer there to encourage plant growth [Music] no primary producers means no food for animals higher up [Music] australian salt water crocodiles suffered similar fates in the 1970s they were on the brink but official protection and better education has seen their numbers steadily improve with populations recently estimated to be in the 100 to 200 000 range [Music] captive breeding and education initiatives are doing what they can to boost wild garill populations only two to three thousand are thought to persist in india lately researchers have happily noted record numbers of hatchlings 2500 counted on the channel river [Music] australian freshwater crocodiles are among the luckier family members their numbers are healthy and they are not endangered american alligators are a rare success story in conservation terms by the early 1970s the population had been decimated by hunting and was declared endangered [Music] subsequent protections and a decline in the commercial use of their skins has resulted in a reversal of fortune for the american alligator today they are estimated to number around 5 million and are now classified as least concerned by conservationists hopefully in time the efforts of dedicated conservation groups will pay off and see the struggling members of this order catch up [Music] all they need is a fair chance after all survival is something these age-old reptiles are good at with millions of years of experience [Music] [Applause] [Music] [Applause] [Music] you

Channel: Free Documentary - Nature

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Keywords: Free Documentary, Documentaries, Full documentary, HD documentary, documentary - topic, documentary (tv genre), nature documentary, Free Documentary Nature, Free Nature Documentary, Crocodiles, Animal Documentary, Crocodile Documentary, Wildlife Documentary, Wildlife, Wildlife Documentary 2020, Alligator, Caiman, Gharials, Saltwater Crocodile, Reptiles, Reptile Documentary, Endangered Species, Apex Predator, Predator Documentary

Id: LUtg1qufIV0

Length: 52min 0sec (3120 seconds)

Published: Fri Oct 16 2020