00:00They're survivors from the age of the dinosaur, fearsome predators, much quicker and more
00:11agile than most people realise.
00:15They can grow to enormous sizes and leap up to their full body length with remarkable
00:22speed.
00:25They can grow into their territory and you can pay the ultimate price.
00:30Their ancestors dined on dinosaurs, while today they feast on a wide range of creatures.
00:42Saltwater crocodiles are the ultimate ambush predator.
00:46They can be found right across Australia's top end, from the mangrove swamps of far north
00:51Queensland to the rivers of the Northern Territory and Western Australia.
01:00Saltwater crocodiles, or salties as they're known to many people, stalk their prey, then
01:05move so quickly that they take their victims by surprise.
01:11The saltwater crocodile is the largest of all living crocodilians and reptiles.
01:18An average male saltwater crocodile can measure up to 5 metres or 16 feet, but some have been
01:25measured at more than 6 metres or 20 feet long.
01:30And the largest of them can weigh over a tonne.
01:37Saltwater crocodiles generally spend the tropical wet season in freshwater swamps and rivers,
01:42moving downstream to estuaries in the dry season, and sometimes travelling far out to sea.
01:50Crocodiles compete fiercely with each other for territory, with dominant males in particular
01:55occupying the best stretches of freshwater creeks and streams.
02:01There are two kinds of crocodiles in Australia, the estuarine, or saltwater crocodile, and
02:11the Johnson's, a freshwater croc.
02:14Both are found in the hot tropical northern part of the continent.
02:18The estuarine crocodile is able to survive quite far upriver in freshwater.
02:23It is one of the most dangerous of all the crocodile family, being the biggest and heaviest.
02:31Unlike other reptiles, crocodiles have four sections in their hearts, like mammals and
02:36birds.
02:38Their long, flattened tail moves from side to side as they swim through the water, with
02:44their legs by their sides.
02:48On land, crocodiles can run very quickly, lifting their bodies up off the ground.
02:53The eyes and nostrils are on the top part of the head, so that they can lie in the water
02:57almost completely hidden from view.
03:03Crocodiles have very strong jaws.
03:07They do not chew their food, but instead swallow it in large chunks.
03:13In the stomach, the food is broken down.
03:16They feed on a large variety of prey such as small mammals, birds, and even domestic
03:23livestock.
03:25Crocodiles grab their prey and move to deep water, where they roll over to drown the animal.
03:34The jaws are heavy set and contain 64-68 teeth, which can grip their prey in an instant.
03:41These eyelids are clear and protect the eyes while underwater, and act as goggles to see
03:46unsuspecting prey.
03:52The Australian saltwater crocodile is a mostly aquatic animal that rarely spends time on
03:57land.
03:59The saltwater crocodile is an opportunistic apex predator, capable of taking animals up
04:06to the size of an adult male water buffalo, either in the water or on dry land.
04:15One amazing phenomena is that they can heat and cool various parts of their body at the
04:20same time.
04:24When they open their massive jaws, they can cool their brain through evaporative cooling,
04:29while the rest of their body is heating.
04:34This perspective allows us to examine his giant teeth, which intermesh perfectly when
04:40the jaws are closed, allowing them to hold on firmly to whatever they grasp.
04:49Once they decide to move, it's with great power and speed.
04:53The crocodiles of northern Australia are voracious meat eaters.
04:57This curious jabiru promises a perfect meal.
05:02The hunt is at first played out in slow motion.
05:05The crocodile moves back into the water to hide.
05:10The jabiru investigates.
05:19Then at lightning speed, the croc attacks, smashing his powerful jaws into the body of
05:23the jabiru.
05:27It's a big meal, even for him.
05:29He prefers to drag it back into the water to tear it apart slowly.
05:37But despite that attack, other jabirus can be luckier.
05:41This one stalks the shoreline very close to six large crocs.
05:46Right along this part of Kakadu, the crocodiles are massing, their numbers increasing rapidly
05:52after hunting was banned 20 years ago.
05:56And with so many mouths to feed, the big population of birds here are the most vulnerable targets.
06:04When males battle for territory, their awesome power can be seen.
06:09Crocodiles will headbutt each other in order to stake claim on their space.
06:16With such a huge number of crocodiles, many people have made a living from these amazing
06:20creatures.
06:25Such is the very real threat to swimmers in Darwin Harbour, the council has appointed
06:29its own croc hunters.
06:33These full-time croc catchers patrol the waters around Darwin every day to catch crocs that
06:38have been caught in their traps.
06:45This croc catcher, part of the team, has lost part of his hand as he tried to trap a giant croc.
06:56Further south on the Adelaide River, croc catchers go out at night to catch big salties.
07:02They'll look out for the eyes of the crocs to show up in their torch lights, then move
07:05in to harpoon them with a small hook that catches under the skin.
07:14Crocs usually put up quite a struggle, and can twist and turn before they're subdued.
07:21In many cases, these crocs are tagged on board, then released.
07:35In far north Queensland, on the edge of the Dane Tree, the Hartley Creek Crocodile Farm
07:40features very close feeding encounters with giant crocs.
07:46Every day, the crocodiles in the local lagoon are encouraged to jump to earn a daily feed.
08:00And at Wyndham, in the far north of Western Australia, catchers come very close to huge
08:04angry crocs in the course of their work.
08:09One vivid example of how high they can jump was filmed at this croc farm.
08:13A number of crocs have jumped close to the camera two metres above them.
08:17On the thirteenth jump, this croc succeeded in snapping its jaws around the camera and
08:22dragging it underwater.
08:34In recent times in Australia, crocodiles have killed one human every two years.
08:41One woman who survived a croc attack is Alicia Sorohan, a 60-year-old grandmother who jumped
08:47on the back of a crocodile that was dragging a family friend from his tent.
08:54Others aren't so lucky, a case of being in the wrong place at the wrong time.
09:03While the saltwater crocodiles may be feared by many, their freshwater cousin, the Johnson
09:08Crocodile, is a much less threatening species.
09:14Australia is the only country inhabited by the freshwater species.
09:22At this waterhole in the Kimberley region of Western Australia, swimmers come close
09:26to a big group of freshies.
09:28It looks dangerous, but the freshies rarely attack, and when they do, swimmers usually
09:33only sustain scratches.
09:38We conclude this production with the salties.
09:41They're the biggest reptile that remain on our planet, the frightening but fascinating
