Saltwater crocodile safari hunting

Yesterday (Wednesday 15 April 2009) the Northern Territory Government unveiled its Draft Management Program for Saltwater Crocodiles in the Northern Territory 2009-13 (you can read it right here). Despite all the recent concerns about crocodile safety issues and changes in management, the one thing that has dominated the news about this new plan is the issue of safari hunting. There's nothing like the idea of people blowing large holes in native wildlife to stir the pot!

But hold on a second, you might wonder, didn't we stop doing that to saltwater crocodiles back in 1971? Well yes, and no. You see, the whole issue about safari hunting has become lost in media spin about gun totin' rednecks, hunters who can't shoot straight and the spectre of croc populations going down the gurgler. What's the real issue here?

The proposal, for that's all it is at this stage, is to implement an experimental harvest of 25 adult crocodiles greater than 3.5 metres in length. That means that breeding females are excluded, and that only adult males can be removed. Considering that 25 adults is an insignificant percentage of the crocodile population here (estimated to be around 80,000 not including hatchlings, and growing) there's no reasonable argument that the number being considered is harmful. What about the effects on population structure? That's a little more uncertain, particularly as it's known that in some areas the very largest crocodiles have a significant role to play in the social structure of less dominant crocodiles in the system. The implications of removing these big "boss crocodiles" isn't fully understood and certainly warrants further investigation.

The big advantage of the safari hunt, however, will be benefits to indigenous traditional landowners and communities - they own the vast majority of land in the Northern Territory for a start, and therefore they own most of the crocodiles here. Most of that land has very little potential to earn income for indigenous communities, but a limited safari hunt where professional hunters pay big bucks to shoot a handful of crocodiles in areas that few people visit would certainly be of great benefit to those communities and landowners. Traditional owners need more options on how to manage their wild resources, and how to make an income from the resources they own, and a safari hunt of crocodiles would give them that.

Sensible management strategies that bring benefits to communities and give them further reasons to value and properly manage their crocodile populations are a good thing. I do have some reservations about the details, about the impacts on large crocodiles, and about the potential loss of very big, rare animals to the Northern Territory (which, let's face it, are what any safari hunter will be after). I think those extremely rare, 18 foot plus saltwater crocodiles are priceless. Zoos overseas have offered 7 figure sums for such animals in the past (at least they did before the economic downturn!) so I hope that traditional owners can be made aware of the value of these exceptionally large animals so they can make an informed decision on how to manage them.

Of course, there are those who oppose safari hunting without exception. They won't even entertain the idea of any management strategy that involves killing a crocodile. I have to wonder whether those people are putting their personal beliefs and feelings ahead of what's best for crocodile conservation. Their feelings are really of no consequence compared with the importance of getting management right for crocodiles. One thing is clear about crocodile conservation: unless you work with the people who live around crocodiles, you will never get them to trust you or to listen to you. Get people on your side, consider what they need to get out of crocodile management, and you might make some progress.

Crocs and shoes

What is it about crocs and shoes? There's a certain uneasy relationship there. Crocs often end up on shoes (or at least their skin does), crocs lend their name to shoes (although there are some that would disagree that they were shoes) and now a well-known fashion brand has decided to celebrate its association with crocs by launching... well, a new set of shoes. They've also put together a rather neat little website celebrating crocodile myths around the world. It's light on content but high on style, and certainly worth a look. It looks like they've taken some of their species facts straight from Wikipedia (not a good omen), and it contains some of the worse proof reading I've ever seen, so don't take it all too seriously.

It's interesting, though, that while many people tend to regard live crocodiles with a great deal of suspicion, the iconographic crocodile is often depicted in a far better light. Many crocodile logos depict cartoony, jolly creatures more likely to dazzle you with their smiles than bite your arm off. Some logos are used in a more traditional sense to represent adventure and the hint of danger. And some are used to emphasise positive traits about crocodiles, such as strength, or stealth, or resilience. The fashion house we're talking above above, Lacoste, has been using the crocodile symbol since 1927 (or so we are told) since Rene Lacoste was compared to a crocodile (for its tenacity) after losing a game of golf. They're quite proud of their logo, considering the lengths they've gone to in the past to stop anyone from trying to use similar logos (although they probably took it a bit far trying to stop a dentist surgery from using a toothy croc logo). Fortunately crocs have survived nearly 240 million years without being copyrighted.

Preventing Crocodile Attacks

Yesterday (15 March 2009) an 11 year old local girl from Lambell's Lagoon was attacked and killed by a saltwater crocodile (Crocodylus porosus). She was swimming with two of her friends near an area known as Black Jungle, one of the few remnant areas of rainforest near Darwin. This tragedy is one of those unfortunate inevitabilities that you dread hearing about on the news. It's inevitable in the same way that you know a dangerous road junction will only be addressed once there's been a fatality there. The difference here is that it's not the place that makes it inevitable, it's the fact that crocodiles are living all around us and yet not enough is being done about safety.

Here in the Northern Territory we get on reasonably well with saltwater crocodiles most of the time. They attract a lot of tourists, their presence employs a lot of local people, and they're one of the more fascinating of our local fauna. Occasionally that relationship becomes strained, and for the next few days this will certainly be the case around Darwin. People will demand answers, how could such a tragedy be allowed to occur, what is going to be done about it, should we start culling crocodiles, and can we prevent it from happening again? There's a general helplessness surrounding the event, as with any tragedy really. But let's go back to some of those questions.

The first is how could something like this happen? We live in close proximity to wildlife in Darwin, particularly the rural area, yet few people expect to find crocodiles near their homes. However, a quick look on Google Earth will reveal that Black Jungle is only a few hundred metres from the nearest rural properties, and that there is easy road access to the area. Zooming out on Google Earth makes you realise that Darwin sits slap bang in the middle of crocodile habitat, and that crocodiles are all around us. Good luck finding a place that's safe to swim here apart from the local swimming pool. The potential for conflict is certainly there, particularly considering that in recent years crocodiles have been branching out from the packed tidal rivers that represent their preferred habitat into floodplains, upstream freshwater areas and around the coast in search of new places to live.

The next question is what can be done about it? Most of the suggestions will fall between two extremes: cull the crocodile population, or be more careful next time. Many people wanting immediate revenge will be swayed towards the former, whereas the government approach is much closer to the latter. Culling sounds sensible on paper, but in reality it's not a viable solution. Ignoring for a moment the potential value that crocodiles represent to the area, culling is not a safety solution. If there are 80,000 crocodiles, how many do you cull? Ten? Five hundred? Ten thousand? When does it suddenly become safe to swim again? Don't worry folks, there's only a few hundred crocs left in this river - you'll be right for a swim!

So what about being more careful next time? I doubt the parents of the girl taken by the crocodile wouldn't find that helpful piece of advice very reassuring. They wanted to know that it wasn't safe for their daughter to swim there in the first place. And therein lies the heart of the matter.

Nobody ever plans on being attacked by a crocodile. Nobody wants to be attacked by a crocodile. Yet it happens. Why? Because the person involved doesn't know the risk. They may not believe that there are any crocodiles in the area, they may not even know much about crocodiles. They may have been misled by people telling them it was safe to swim there, or they may simply have been doing this for years without any hint of a problem.

Whatever the reason, the solution seems obvious. People need to be aware of the danger that crocodiles can pose, and they need to be aware of where crocodiles can be found throughout the year. They need to know that crocodiles are now everywhere, potentially in any body of water that doesn't have a fence around it, and that swimming is not an option anymore. The last time there was a major educational drive on crocodile safety in the Northern Territory was nearly 30 years ago, and a lot has changed in that time not least the crocodile population and its distribution. Despite this, much of the same information is being used today and the differences between then and now are not being made clear.

People must have up-to-date and factually correct information about the danger posed by crocodiles, not only for their own safety but so that transparency and trust can be established. If people don't respect what you're telling them about crocodiles, you can't expect them to listen.

Supercroc

On Saturday 7 March at 6pm at the Museum and Art Gallery of the Northern Territory I'm giving a short presentation on crocodilians called Crocodile: Predator Evolved. Just to further encourage you to rush out of the door to get your seat, the headline act is Dr Paul Sereno (University of Chicago) giving a talk on fossil crocs including Supercroc. We're all hoping that Paul will tell us a little about a few recent fossil croc discoveries, creatures not quite as large as Supercroc but a whole lot more bizarre. In fact, it's the subject of a National Geographic documentary that we're filming with Paul here in Darwin at the moment. I don't think he can get over how remarkable galloping freshwater crocodiles are at close range - there's perhaps no better modern analogy for how these extinct terretrial predators used to hunt. If they didn't catch up with their prey, they probably scared them half to death from the sight!

Happy 200th Birthday

Charles Darwin was born on 12th February 1809, 200 years ago almost to the day. He popularised and promoted the idea of natural selection and evolution, a concept that he wasn't necessarily the first person to think about but certainly the person who brought the idea to a mass audience. And what a negative reaction he recieved back then, and judging by modern standards there is still a lot of controversy about it. The kicker was the concept of humans sharing ancestors with apes, rather than being created through divine means. Regardless of your beliefs, it has to be said that Charles Darwin's theory of evolution has had a profound and lasting impact on society.

That being said, living in the City of Darwin (named after the Beagle landed here and named it after their most famous passenger) gives a certain added significance to Darwin's birthday. All this year there are bicentenary celebrations in Darwin, and they have started with perhaps the best. As a way of illustrating Darwin's theory of evolution, the Museum and Art Galleries of the Northern Territory has opened a new exhibition on Supercrocodilians - essentially, using crocodilians (or crocodyliforms if you want to be pedantic about it) to show how the fossils evidence shows their change over time. It's an excellent exhibit with some absolutely stunning croc skulls and taxidermy mounts. I was at the opening yesterday, but I spent so much time talking with various people that I didn't get chance to absorb it all properly.

So, armed with a camera, I will return! And I will post some of pictures of grinning croc skulls here for your edification and enjoyment.

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!

The largest saltwater crocodile in the world

How many times I have been asked this question: which is the largest crocodile in the world? Of course I always say that it's a saltwater crocodile (Crocodylus porosus) because the evidence we have supports that. But there's not always a lot of actual evidence of large crocodile sizes, just plenty of "big croc" stories. Still, the biggest crocodile ever measured (with a tape measure) was around 6.3 metres long (20.7 feet) from Papua New Guinea.

But what about the largest living crocodile? There may be several huge crocs living in the wild that we don't know about, but the largest living crocodile in captivity has been living on Green Island near Cairns for over 20 years. His caretaker is George Craig, a former crocodile hunter who now runs Marineland Melanesia, a shrine dedicated to crocodiles on the island. It is quite a remarkable place, which is entirely reflective of how remarkable George himself is. You see, George loves crocodiles with the kind of passion that you rarely encounter. He respects them enormously. This is why we were very keen to meet and talk with him on a recent trip to Cairns. The truth is we could have talked for weeks about crocodiles, but we only had a few hours. George was very keen to show us his pride and joy, the largest living saltwater crocodile in captivity. His name is Cassius, and he originally came from the Northern Territory. At the time he was a little under 18 feet (5.5 metres) long, but he's now around 18.5 feet (5.6 metres). Like many extremely large crocodiles, Cassius is as gentle as a lamb around his keeper, unless some food is dangled in front of him. Then, looking remarkably like a dinosaur from a forgotten age, he explodes into action and grabs the food from George. The word "grab" doesn't really do it justice, as the item of food often explodes under the pressure of those jaws. It's a remarkable and sobering sight, and if you ever need reminding how awesome crocodiles really are then a trip to Green Island to see Cassius is essential. Don't forget to talk to George Craig - rarely will you find anyone who knows more about crocodiles and understands them like he does.