More on the giant Philippine saltwater crocodile

I've had a look at several photographs of that giant Philippine saltwater crocodile, not to mention a few videos, and I must admit that's probably the largest crocodile I've seen. There's a good chance that this one isn't an exaggeration, although I'd still like to see the measurement and weight independently verified to be certain. I'm so used to reading stories with exaggerated crocodile lengths, that when a genuine enormous crocodile does surface it can be difficult to accept at face value. But from what I've seen, I'd be prepared to believe this one. It's certainly at least 18 feet long, bigger than Cassius, and hopefully it really is 21 feet (6.4 metres). There has been some doubt raised about the weight, but there's so little information on the weights of large crocodiles out that that size extrapolations from existing datasets are likely to be inaccurate for very large crocs. I have a feeling we'll be getting some independent verification soon. I'll keep you posted, but it's pretty exciting to see such a huge crocodile regardless of the actual figure attached to it.

Gharial

True Wild Life | Gharial | The gharial is a large-sized reptile found in the murky waters of Northern India and the surrounding countries. The gharial is closely related to other large reptiles including caimans and alligators, although the salt-water crocodile is believed to be the gharial's closest relative. The gharial is most commonly found in the calmer areas of the deep, fast-flowing rivers of the North Indian subcontinent. The gharial spends most of its time in the water as it is not well suited for a life on the land, due to its short legs.

The gharial (along with the larger adult salt-water crocodiles) is the longest of this group of large reptiles, with there having been reports of adult male gharials reaching more than six meters in length. The elongated snout of the gharial is ideal for catching fish in the water, and contains more than 50 sharp teeth. The gharial is a generally solitary predator and does not have the same terrifying reputation for eating humans as crocodiles do. Although the gharial has been known to show aggressive behaviour towards humans at times, the shape of the gharial's snout makes it difficult for the gharial to consume anything too big.

The gharial is a carnivorous animal and a dominant predator within its environment. The only time that this isn't the case is when the gharial share its territory with a large salt-water crocodile. Fish is the primary food of the gharial along with insects and occasionally small animals. Due to its large size, the gharial has no natural predators within its environment besides humans who hunt the gharial, often for leather or meat. The gharial has also been devastatingly affected by the increasingly levels of pollution in the water and is today considered to be critically endangered in the wild.

The female gharial makes their nests and lay their eggs during the dry season when the river shrinks exposing more the sand on the river banks. The female gharial lays between 30 and 50 eggs which are buried in a whole in the sand by her. The baby gharial emerge from the underground nest after a few months and are protected in the water by their mother for a few days, until they are able to fend for themselves.

Crocodile

True Wild Life | Crocodile | Crocodiles are one of the planets oldest living creatures, thought to be around 200 million years old which means that crocodiles were around in dinosaur times. Crocodiles live throughout the watery tropics of Africa, Asia, America and Australia, congregating in freshwater environments in the worlds lakes and rivers. Crocodiles feed on fish, reptiles and mammals, the prey size generally dependent on the size of the crocodile.

Legend has it that if you are being chased by a crocodile, the only chance you have of getting away is by outsmarting the crocodile. Apparently the way to do this is to run away from the crocodile diagonally down a hill! The myth says that crocodiles have a very slow turning circle meaning that if you run diagonally, the crocodile theoretically cant catch you!

As crazy as it sounds, crocodiles are known to swallow stones when they are on the banks of the water. The crocodile does this to not only help its digestive system but also to aid the crocodiles water buoyancy. It is thought that by swallowing stones, the crocodile may also be able to swim to deeper parts of the water.

The crocodile is also unable to stick out its tongue (probably from all those stones in the crocodiles stomach)! The crocodile is able to regrow new teeth very quickly after losing the old ones, throughout the crocodiles life.

Caiman

True Wild Life | Caiman | The caiman is a large aquatic reptile found in the swamps and tropical rivers that cover Central and South America. Although the caimans have much narrower bodies, they are most closely related to alligators and crocodiles. Caimans are found in a variety of habitats throughout Central and South America from marshes and swamps to mangrove rivers and lakes. As with other reptiles, caimans have scaly skin and live a fairly nocturnal existence.

Caimans range in size from the dwarf caiman which measures just over a meter in length, to the black caiman which can to grow to be nearly 5 meters long. The black caiman is the largest caiman species in the world and is found in the slow-moving rivers and lakes that surround the Amazon basin. There are six different species of caiman found throughout the watery, jungle habitats of Central and Southern America. The average length for most of the other caiman species if about 2.5 meters long.

The caiman is a carnivorous predators and, like the alligator and the crocodile, the caiman has a diet that consists of a great deal of fish. The caiman also hunts insects, birds and small mammals and reptiles. Due to the large size and ferocious nature of the caiman, it has few natural predators within its environment. Humans are the main predators of the caiman as they have been hunted for their meat and skin. Jaguars are the only other predator of the caiman.

Female caimans build a large nest in which to lay their eggs, which can be more than 1.5 meters wide. Female caimans lay between 10 and 50 eggs which hatch within about 6 weeks. Once they have hatched, the mother caiman takes her young to a shallow pool of water where they can learn how to hunt and swim.

Alligator

True Wild Life | Alligator | Alligators are in the same family as crocodiles but are native to only two countries, which are the USA and China. Alligators tend to be smaller than their crocodile cousins but have been known to move at speeds of up to 30mph on land making them one of the fastest large reptiles in the world. Alligators tend to live to about 50 years old or so but some have been known to live at least another 20 years when in captivity. Alligator DNA is thought to date back to even before Dinosaur times meaning that the alligators survived whatever it was that the dinosaurs didn't!

The Alligator is generally a solitary predator, but smaller species of alligator however, are known to stay together in groups especially when hunting. The Alligator eats fish, small mammals and birds, but the alligator has also been known to attack much larger animals.

The American alligators are found in the south-eastern USA, all of Florida and Louisiana, the southern parts of Georgia, Alabama and Mississippi, coastal South and North Carolina, Eastern Texas, the south-eastern corner of Oklahoma and the southern tip of Arkansas. The majority of American alligators inhabit Florida and Louisiana, with over a million alligators thought to inhabit each state.

The American alligators live in freshwater environments, such as ponds, marshes, wetlands, rivers, lakes, and swamps, as well as brackish environments. Southern Florida is the only place in the world where both alligators and crocodiles live in the same place.

The Chinese alligator is currently found only in the Yangtze River valley and the Chinese alligator is extremely endangered with less than 100 Chinese alligators believed to be left in the wild. There are many more Chinese alligators that live in zoos around the world than can be found in the wild.

Adult alligators have been known to hunt deer and are well known to kill and eat smaller alligators. In some cases, larger alligators have been known to hunt the Florida panther and black bears, making the alligator the dominant predator throughout the their environment.

Unlike large crocodiles, alligators do not immediately regard a human upon encounter as prey, but the alligator may still attack in self-defence if provoked. Alligator attacks are uncommon but alligators have definitely been known to attack humans if the human is in the alligator's territory.

Crocodile myths #1 - the curious trochilus

I intend to make this a continuing series of articles, at least until I run out of crocodile myths to discuss. There are, as you might infer, no shortage of wild and wonderful myths associated with crocodiles (and alligators). Many of these seem to originate with the Greek philosopher Herodotus, and if he were still around I'd have a bone to pick with him. Whether he was misinterpreting crocodile natural history, or whether he was simply making stuff up is hard to say, but his influence has reached across the millennia.

One of the most popular myths is that of "trochilus" as Herodotus, and later Aristotle and Pliny, call it. This is supposed to be an Egyptian bird that flies into the mouth of a basking crocodile and feeds on scraps of food and leeches attached to the jawline and tongue. Herodotus describes it as follows: "...for the crocodile, when he leaves the water and comes out upon the land, is in the habit of lying with his mouth wide open, facing the western breeze: at such times the trochilus goes into his mouth and devours the leeches. This benefits the crocodile, who is pleased, and takes care not to hurt the trochilus." Many have attributed this behaviour to the Egyptian plover (Pluvianus aegyptius) which is a very common bird often seen around basking Nile crocodiles, although there's no proof that this is what Herodotus was referring to.

This description of a bird that cleans the teeth of crocodiles has undoubtedly entered popular culture, so much so that crocodiles are often used by advertising agencies to promote dental hygiene. But is it true? Do plovers or indeed any other birds actually clean the teeth of crocodiles?

(c) Warren Photographic, Used with Permission

I'll begin my answer with the opinion that I don't believe a word of it. However, there's more to this story than just a simple yes or no. First off, there's no evidence anywhere in photographs or film to show birds cleaning crocodile teeth or ripping leeches from their tongue (with the exception of that particularly clever digital fake you see above; click on it for the full version) and no published reports of it in peer-reviewed literature. I'd have thought a mutual relationship of this kind would have been easily observed by now. Secondly, contrary to popular belief crocodiles do not need their teeth cleaning. They regularly shed their teeth and replace them with new ones: each visible tooth has a solid tip but a hollow base and inside this base, like a set of formidable Russian dolls, are smaller teeth waiting to emerge. Tooth decay, broken teeth and staining are never a permanent problem for a crocodile. Thirdly, food simply cannot get stuck between their teeth - they are too widely spaced for food particles to get jammed in there, and they are regularly washed with water every time the crocodile slides off the bank. While bacteria and microscopic particles can indeed become prevalent around the base of the teeth, these are not problems that are going to be solved by the pecking of a bird large or small. Leeches are another matter, and crocodiles certainly suffer from these insidious passengers. It's generally thought that gaping the mouth during the day helps a crocodile to dry its mouth and hence discourage leeches, but do birds also help out? If they do, it hasn't been documented as such.

So what's going on? Am I just a born skeptic? Perhaps I am, but that doesn't mean there isn't something in this compelling relationship. Birds of various species are often found feeding in close proximity to crocodiles, and immobile crocodiles basking on the bank in the sun are rarely if ever concerned about birds wandering between them, standing on their back, or straying close to their jaws. Birds are opportunists too, and they will feed on flies and other insects on and around crocodiles. It may even appear that they are removing flies from the crocodile's jaws on occasion. But extrapolating this into a mutual relationship between crocodile and bird is going a bit far. Crocodiles hardly benefit from the presence of the birds, and yet they tolerate their presence because it's just not worth chasing them. Crocodiles aren't always in the mood for feeding, and they're smart enough to let difficult to catch prey like alert birds pass them by.

So if you ask me, the crocodile bird exists in name only. There is no mutual relationship between them, as none has ever been seriously documented, no advantage would be gained by the crocodile, and the hypothesis just doesn't add up. Of course, I like to think that I'll reconsider anything based on actual evidence. I wait in hope.

Crocs on a plane

Oh no, I didn't just use that headline did I? It had to happen of course, someone released a crocodile on a commercial airliner. Passengers screamed as a huge crocodile scuttled down the aisle. Hold on a second, it was actually just a hatchling, less than a foot long. Hatchling crocodiles look more like geckos, so there's really not much of a story here other than the opportunity to riff on an old meme. Still, you'd be surprised at how often this happens, crocodiles escaping during flights that is. One of my colleagues told me a story of something similar several years ago, and in that case he was able to grab the crocodile as it wandered out from under his seat. Of course, the wider implications of this story are the prevalence of smuggling exotic wildlife - highly valuable contraband. They often say that nature will find a way. Well, when it comes to valuable resources, people will also find a way. Of course, you don't find people smuggling large adults on commercial flights - they don't fit so easily into your flight bag.

As you might imagine, nobody on either flight described above claimed their crocodile.

There are no longer 23 species of crocodilians

In fact, there are 25 of them. Possibly more. While we are all extremely concerned about the handful of critically endangered species that are in serious danger of disappearing from the wild forever, it would seem that there are a few crocodilian species that we know nothing about. It's understandable. For a start, most crocodilians look very similar to each other. You have to be very familiar with each species before you can reliably tell them apart, and even then it can leave experts guessing without a very detailed examination of the skin. To complicate matters further, some variation in appearance is normal - a scale here, and colour change there. There are many, many sugggested species, sub-species and regional variations of crocodilians, but up until recently there were only 23 commonly-accepted species.

Enter genetic analysis. This is a tool that boils all those visible and invisible differences between species into a sequence of base pairs - a genetic formula for a species. So if you compare two individuals you'll always find differences (unless they are identical clones). The problem is, which of those differences are important in determining whether they are genetically compatible? In other words, whether they are the same species or different species?

To complicate matters even further, hybridisation is possible between quite a lot of crocodilian species. You remember the part during biology lessons where the teacher told you that only if two individuals could breed and produce fertile offspring they were of the same species? Well, it was wrong. Crocodilians demonstrate this very well, and it makes it even more difficult to say for certain which species is which.

So, genetic analysis should be able to solve this dilemma... if we knew what to look for each time. The main problem with some of these crocodilians is getting enough genetic samples covering their entire distribution to enable meaningful comparison. Without it, you end up with uncertainty, but with sufficient samples you can say with more confidence whether the species you're testing comprises one or more species. This is essentially what Mitchell Eaton and his team from the American Museum of Natural History have done with the African Dwarf Crocodile (Osteolaemus tetraspis). It was always suspected that there were two subspecies of dwarf crocodile: O. tetraspis tetrapsis and O. tetraspis osbornii based purely on morphological differences. Comparing photographs of the two candidates, the differences in the shape of the skull and the scalation were quite noticeable, but this alone was never sufficient evidence to separate them. But now that Eaton's team has compared the genetics across a sufficient wide range it's clear that there are major genetic differences there. The only thing is, there are enough differences to indicate three separate species, not just the two that were previously suspected. Perhaps the presence of this third species was sufficient to confuse any meaningful morphological comparisons earlier? Whatever the reason, we'll all have to revise our websites and our textbooks!

The three species? The third is as yet unnamed, but the first two are O. tetraspis and O. osbornii. It will be interesting to see what they name the third. Suggestions welcome!

Travels around Queensland

It's been a little while since I last posted a blog update, but that's because Erin and I have been travelling around Queensland working on some crocodile consultancies. We've been staying in isolated communities usually with very limited communications, and often working at night at very odd hours - going to bed at 6pm and getting up at 1am to catch the right tide never seems to be easy. Yet there's something oddly liberating about working for several hours on a river at night and then getting back just as the sky begins to brighten in the east and the first rays of dawn appear.

We get back to Darwin in late October, so hopefully normal blog service will resume then. That is, after we've both caught up on our sleep.

Creatures of Bullo River

The land around Bullo River Station is spectacular, to say the least. And its inhabitants are equally remarkable. As part of our ongoing study into pygmy freshwater crocodiles (see previous post) we keep bumping into critters that seem even more intriguing.

Every two to three days, Franz Ranacher drops us off with his Robinson R44 helicopter into the upstream escarpment country. Once the fading sound of rotor blades has left us behind, we're surrounding by the sounds of birds, chirruping insects and squeaking frogs. You really don't have to go very far to find something fascinating. Our surveys involve long walks during the day along the creeklines and isolated pools, returning at night to spotlight for crocodiles and hopefully catch a handful for tissue samples. So we get to see a lot of diurnal and nocturnal wildlife. Occasionally we find something that really takes our breath away. Apart from the crocodiles of course, which are always cause for excitement.

So if you'll excuse my slight devitation from the crocodile theme of this blog, here are a couple of really cool critters. You can call them honourary crocodiles if it makes you feel any better about it!

The first is a Northern Knob-tailed Gecko (Nephrurus sheai). This little fellow was hot-footing it along beside our mozzie dome one night, looking more like a wind-up mechanical toy than a reptile. We managed to intercept him with the camera and took a few snaps. They really do have a tiny little, stunted-looking knobbly tail. I'm sure the first one to be found was suspected of having its tail bitten off when it was young... and then the second... and then they all seem to have these bizarre tails! They also have an enormous head, so much that they always seem to be in danger of pitching nose-first into the sand. Their entire body is also covered with tiny, rosetted scales. With their huge eyes and disarmingly amused expression, they're not the kind of thing you forget easily.

The second is a Leichardt's Grasshopper (Petasida ephippigera), which seem like they've come straight out of a children's toyshop. Some Aboriginal people call these "Children of the Lightning Man" and you can probably see why. As you can probably imagine, they taste pretty bad, which explains why they're pretty laid back when you find one. Not that we had any intentions of eating one to test the theory. These grasshoppers are also used as a sign of the oncoming wet season. Although it is still early September here, the humidity is starting to rise and the days and nights are getting progressively warmer. These kinds of triggers cause the adult form of the grasshoppers to emerge, where they are said to look for the lightning storms that signal the beginning of the wet season in November.

Pygmy crocodiles of Bullo River

Back in early 2006, we were contacted by Marlee Ranacher from Bullo River Station about their freshwater crocodiles. Not any old freshwater crocodiles, however, these were pygmy freshwater crocodiles. These tiny bundles of attitude are essentially very similar to freshwater crocodiles (Crocodylus johnstoni) but they live in far upstream escarpment areas around the Northern Territory in particular. In these areas there is very little food, mostly various species of small fish no more than a couple of inches in length, small crustaceans and... well, that's about it. As a result of not having much food available, they don't grow very large. They are essentially stunted crocodiles, but they have adapted to this unique environment. And, more importantly, they are essentially geographically isolated from downstream, "normal" freshwater crocodile populations. That in itself makes them interesting, but they have the potential to be even more interesting.

If they are geographically isolated and there is little or no genetic input from more downstream populations, then they have the potential to become genetically distinct over many generations. It's evolution at work. One tantalising clue comes from a breeding pair of these tiny crocodiles, originally from the upstream Liverpool River, that were bred by Melbourne Zoo. The offspring were fed a normal captive diet, and therefore they should have grown into normal freshwater crocodiles. However, they did not - they were also stunted. Although that doesn't prove anything, it makes enquiring minds want to know whether they are indeed different.

There is another spanner in the works. Cane toads! These warty horrors can get into the most amazing places, and that includes upstream freshwater escarpments. We already know that freshwater crocodiles eat cane toads, and that they are susceptible to their toxin, and a recent study showed a 70% decline in crocodile populations before and after cane toad arrival. Pygmy crocodiles, being smaller, are more susceptible to the toxins from these toads, and therefore we are all extremely concerned about the long-term impact of toads on these pygmy populations.

So we are here at Bullo River conducting surveys and to collect tissue samples from a representative sample of crocodiles. The surveys involve walking along an upstream creek during the day, mainly to find pools and to figure out how to climb between them - some areas are quite treacherous to get around - and then walking back at night with a headtorch and spotlight to count the number of eyeshines in each pool. Crocodiles have a reflective layer in the retina of their eyes, and the reflected light is bright red so they are quite easy to see at night if they are on the surface. The problem is, many crocodiles are not on the surface - usually they're hiding amongst vegetation, under logs, and particularly in cracks between submerged rocks. So you really have to spend a lot of time looking around, double and triple checking each pool.

Catching them to take a tissue sample is another challenge. The best, and perhaps only effective way of doing it is to get into the water and catch them by hand. Most of the time this isn't a problem because they're fairly small, although trying to hand-catch a 1.5 metre crocodile (the biggest any pygmy croc appears to get) requires a bit of care! Many of the crocodiles are also very naive towards people and will happily swim over to check you out. Some of the larger, territorial males aren't best pleased by your presence either. Once captured, however, they become quite placid and can be measured and photographed with ease. We take a small sample of tissue from the tail, basically a piece of mostly dried skin, and then release the crocodile back into its pool where it glowers at us. If only we could tell them that it's all in their best interests.

We're here for a few more days yet and we've seen some pretty amazing creatures up here, so there'll be more to come.

Smaugasboard

No really, I spelled that correctly. You see, we have a crocodile called Smaug in our garden. He's a 14.5 foot (4.5 metre) long Australian Saltwater Crocodile. We called him that because, well, he looks like a smug dragon that could be sitting on a large mound of golden coins. For those that don't immediately see the references, that's what Bilbo Baggins finds the dragon Smaug doing near the end of J.R.R. Tolkien's The Hobbit. Considering that Peter Jackson and Benicio del Toro are producing the movie version of the book at the moment, we thought of sending them Smaug's audition tape. He's quite a dynamic presence, as you can see from the photograph (thanks to Graeme Sawyer).

Oh and incidentally, the board that we used to carry Smaug on when we built the enclosure? That's the Smaugasboard.

Attacked by a crocodile while editing a film

Ok, that deliberately provocative title should not be taken at face value! However, I figured that "Cleaning the croc pool and doing some NLE" perhaps wasn't quite so exciting. But yes, it's all true. Today we decided it was time to clean the underwater filming pool, as we have a film crew using it next week. Cleaning involves attaching a long hose to the pump, setting it to waste, and sucking out any leaves and other detritus that has accumulated in the filming room. If we didn't do this, entering the water would stir up sediment and reduce visibility a little too much.

Cleaning is much easier on scuba, so tanked up I got into the water and started to clean. Smaug, our large male crocodile, wasn't too impressed by all this banging and splashing that I was doing and came across to investigate. It's quite a shock, even now, to realise that your face is about half a metre from a steel barrier behind which a very large crocodile is studying you intently. I noticed he was attracted to the bubbles that I was exhaling, and hence he was following me round. It didn't take long before his curiosity got the better of him and he struck at the fence with a loud clang. Underwater, a loud clang sounds more like someone dropping a pin on the floor. At least, to insensitive humans such as myself. However, with my face mere inches from his crashing jaws I was in no doubt what was going on! For just the briefest moment, I found myself wondering what I was doing. There I was, 2 metres under the surface with a 4.5 metre (14.5 ft) saltwater crocodile trying to get at me. The only thing separating us was a steel mesh barrier. A very strong one, it must be pointed out, but the feeling of being in the wrong place at the wrong time is a hard one for your mind to shake off.

Of course, it all looked absolutely spectacular and I wished I had an underwater camera with me. That is, naturally, the entire point of the facility. It is a completely unique way of seeing saltwater crocodiles. The fish swimming around my head didn't seem too impressed, though - they were more curious what on Earth I was doing down there too. By this time the floor was clean and I was getting cold. Next time I will persuade the film crew to avoid coming at the coldest time of year!

As for editing the film, well that all seems rather mundane after that little story. But we're pretty pleased with it. It's a 3 minute short film about crocodiles, with music and sound effects but no narration. There are sumptuous images of crocodiles and habitats that we filmed in DVC PRO HD late last year, and it's all coming together very nicely. I wrote the music in a few hours, but the biggest challenge was matching it with the images. Our NLE software isn't really equipped for music synchronisation, so I did it the old fashioned way. Anyway, it has reignited our appetite to produce longer films, without a doubt. It also justifies the purchase of our new plasma HDTV because, frankly, it looks stunning on there. It will soon be on display running continuously on multiple HDTV screens at Crocosaurus Cove, which will be great to see.

Oh look, a crocodile!

There's a new tourism facility opening in Darwin very soon called Crocosaurus Cove. It might sound like a great place to lie on a beach towel and soak up the sun while giant reptiles wander past, but it's actually going to be the equivalent of an aquarium for crocodiles. Big crocodiles - we're talking 18 footers here. And Big Gecko was contracted to assist with moving them from the Darwin Crocodile Farm into the new facility, situated in the middle of town. Don't worry, there will be pictures to come but for now I should relate a cautionary tale about driving large crocodiles down the highway on a Saturday! It's the kind of activity that can be extremely hazardous, but not for the reasons you might think. Catching and transporting the crocodiles is a piece of cake really, but getting one down to highway into the town centre without causing a major accident? Now that's quite a job! People nonchalently overtaking in the right-hand lane would suddenly realise they were overtaking a trailer holding a very large crocodile, slam on the brakes, and fumble around on the back seat for their mobile phone camera so they could show the kids, all while weaving around wildly. When they weren't taking their eyes off the road, their passengers were winding the windows down to gesticulate towards the crocodile in case anyone had failed to spot it. We even had cars slowing down in front of the towing vehicle, causing our driver to overtake just so they could take a photograph as it passed them.

And people think crocodiles are dangerous...!

Three cheeky monkeys, one crocodile

Just got back from the Darwin premiere of Black Water, not a film about rogue security agencies in Iraq but rather a crocodile thriller set in the Northern Territory. As you can imagine, the crocodile featured in the film wasn't interested in tea and biscuits with the cast. It is the latest in a series of movies about killer crocodiles, but I reckon this was easily the best. Of course I may be slightly biased because I did a lot of work on the crocodile sequences for the movie!

The film is loosely based on a couple of actual crocodile attacks that occurred in the NT, but they are used as a premise to set up the situation. You might call it a situation horror film: what would you do if you were stuck up a tree surrounded by water containing an unfeasibly hungry crocodile? It's an interesting premise because it plays upon your fears: not knowing where the crocodile is, nor what its motives are, and not really knowing what to do. And although the crocodile behaviour ends up being a little unrealistic by the end of the movie, it was certainly effective. Of course, I'm a sucker for films that take their time to establish atmosphere. I'm not a fan of most modern "horror" films that mistakenly believe that gore is a substitute for generating tension, and in that sense Black Water is quite old-fashioned.

We ended up doing most of the crocodile effect shots for the film, and I was intrigued because the director wanted to use real crocodiles instead of CGI. Perhaps that was a question of budget (Black Water cost $1.2 million Australian dollars) but it turned out for the best - there's no question that the effects look an order of magnitude better and more convincing than any CGI beast, because the crocodile was in control of its movement and not a computer animator. I've long been frustrated by how crocodile effects have been handled in movies, so what better way to show how it should be done than turn to the experts themselves - saltwater crocodiles. Our job was to get footage of the crocodiles doing what was in the script!

Most of this was simpler than you might think if you use the right approach - understand each individual crocodile, know what its strengths are, and encourage it to perform the right behaviour. It's a case of working around the animal, and adapting to what it wants to do. Of course, the director had such a low budget that we had to cut a few corners. One sequence involving a crocodile climbing into a boat could have been done by training the crocodile - something we've done several times in the past - but that takes time. Instead we had to improvise, encouraging the crocodile to run down a bank into the boat rather than climb over the side. And getting it out again? Why, just tip the boat! With a bit of creative editing it ended up looking quite convincing.

In fact, the end result looks so convincing that I've seen reviewers who couldn't tell whether we were using real crocodiles, CGI or models. Of course, the actors were mostly acting against a blue screen so that the crocodiles could be digitally inserted later, but it's real croc behaviour on screen and not an animator's idea of croc behaviour. A lot of these techniques come from years of working on natural history films where you need to understand the animals in order to know how, when and where to film them.


Things didn't always go to plan, though. The director wanted a specific shot of a crocodile launching itself towards camera left, jaws opening. We knew the crocodile that would deliver this shot, so we used a chicken to entice him towards us. The camera was housed in a protective case which was suspended near the chicken. I did warn the camera operator not to get too close to the head or the casing might get bitten. Too late. The crocodile took one look at the chicken, then one look at the white camera housing that was twice the size, and figured it would go for what must have looked like an enormous chicken! Crunch! The croc punctured the housing in several places and dragged it off its mount into the water. Fortunately the camera operator whipped it out of the water by its cable before the crocodile could find the soft, chewy centre. Scratch one very expensive casing, but it did get them a far better shot that ended up in the film.

Black Water has already opening theatrically in the UK, and it's available in the US on DVD, and finally now opening in Australia theatrically. It's definitely worth watching if you want to see real crocodiles on the big screen.