Dad talking to Molly trying to keep her settled

(Click photos to enlarge)

During the early 1970s, Dad (Bob Irwin) was very concerned about the 'shoot-on-sight' attitude towards crocodiles and decided that he needed to commit time and money to conserving Australia's number one predator.

The mid 1970s was a monumental period for Australia's crocodiles as legislation was established to fully protect both species, and Dad and myself (barely a teenager) spent many moons catching and translocating crocodiles caught up in the rapid human encroachment on the east coast of Queensland. Throughout our early croc-catching endeavours we utilized every known capture technique.

During the 1970s we used our knowledge and good old Aussie outback innovation and developed the soft mesh trapping technique which to this day is not only 100% effective, but also grants the trapper a wealth of knowledge about the crocodiles habits, sizes and demeanours within the territory being trapped.

Surveying the banks of the waterways for slides, claw marks, and imprints will determine the whereabouts and habits of large crocodiles. Once the crocodile's territory is determined, a suitable trap site should be located, preferably within 50m (164ft) of the crocodile's preferred haunt.

Crikey, we’ve come a long way in our croc trapping technology since 1980. Australia Zoo’s International Crocodile Rescue allows me the freedom and engineering expertise to design, build, trial and utilize the most advanced trapping techniques in the world.

To date, my most successful crocodile trapping mission was in Weipa during August 2004, when we caught 33 adult Saltwater Crocodiles in 14 days. These were all documented in our current crocodile research project titled ‘Crocs in Space’. Australia Zoo is working with the Environmental Protection Agency and the University of Queensland in carrying out the most cutting-edge croc research in the world.

Another recent testimony to the highly efficient capture of designated problem crocodiles, was the capture of 'Digger' in the Gulf of Carpentaria in one hour in total daylight. The croc was trying to get in the trap whilst Stuey was still setting it.

I use three distinct trapping methods:

1. Soft mesh trap
2. Gate trap
3. Floating trap

All three methods require highly trained and skilled people to set them up, place them in the croc's territory and extract and restrain the captured crocodiles.

A 15½ foot male Saltie I’ve trapped in a soft mesh trap.		A 13-footer I’m releasing from a gate trap.
A 15-footer trapped in one of my brand new floating traps.

1. Soft mesh traps

Up until the 1990s this is the only trapping method I used. The most important thing with soft mesh traps is the amount of knowledge you need to set the trap and the amount of knowledge you learn about the crocs in the area you're trapping, whilst your trap is set. Soft mesh trapping provides the trapper with an intimate understanding and awareness of the entire ecosystem.

In the water, crocodiles are impossible to study. It’s very difficult to accurately estimate their size when all you see is a head that looks like a piece of driftwood from a distance.		Once a croc basks on a mud bank, he leaves a track which is all the evidence that’s needed to understand the size, density, hierarchy and behavioral patterns of the crocodiles in the area.
This croc will leave an excellent imprint in the mud.		"Hey Dad! I reckon this croc is just over 14 foot! It's definitely the one you’re after."
A track left in the mud is known as a 'slide’.

A good location for a soft mesh trap is a gently sloping to flat graded bank. It needs a solid tree with a branch height of 6m (20ft) that's capable of easily handling 400kgs (881lb) of force, within 10m (33ft) of the trap site.

The trap can be set on land within 5m (16ft) of the water; in shallow water up to 1m (3ft) in depth; or below the high tide mark so that as the tide comes in and the trap is semi submerged, water level should not exceed 1m (3ft) in height, otherwise there is a risk the trapped crocodile could drown.

The mesh used for the trap is a cod end off a scallop trawl net with a 16 tonne rating. The mesh dimensions are 50mm x 50mm (2in x 2in) in nylon cord no less than 5mm thick.

Wes and Ranger Barry Lyons admire
their trap in Cape York Peninsula

The trap dimensions are determined by the size of the crocodile to be captured. In the set position, a crocodile must be able to enter the trap without touching the side or roof. Dimensions for a trap designed to capture any sized crocodile in excess of 12ft (3.6m) would be 4.8m long x 1.5m wide x 0.9m high (16ft x 5ft x 3ft).

Mesh sitting well, but still needs barricades around it to stop the croc from attacking the bait from the sides.

'Wombat' at the rear of the trap

To set the trap, a trap site is cleared, the trap unrolled, short sticks are cut and driven through the mesh along the bottom on each side (this anchors the trap to the ground, ensuring an entering crocodile won't get caught up in any loose mesh on the floor of the trap). Mud and leaf mould can be scattered on the floor to help create a more natural substrate and assist in holding down the trap's shape.

It's all about sticks and strings

Sticks are then cut at approximately 1.5m (5ft) in length and driven down each side of the trap, approximately 500mm (1ft 6in) apart. The top/roof and sides are then tied to these sticks with a single hemp string. The string must be of a light breaking strain, such that a thrashing crocodile would easily break them, but also strong enough to support the trap.

Light hemp strings support the trap

Once all the stick and string supports are in place, the trap should sit in an even, rectangular shape.

Lookin' good!

A 12mm (1/2in) silver rope is woven through the mesh at the entrance/mouth of the trap, then threaded through a spliced loop on the end of the rope, to create a lasso/drawstring effect.

Stuey shows how a drawstring should pull up
tight and off the ground. This one is perfect.

The end of the trap is secured by weaving 12mm (1/2in) silver rope through the end meshes, pulled constricting style until all the mesh pulls together, then tied off securely to a large tree or object which a large crocodile could not dislodge. This is the anchor for the entire trap and must be secured, with no chance of fraying or breaking of the rope or dislodgement.

One or two (depending on crocodile size) bags filled with 50-100kg (110-220lb) of dirt, sand or mud, are hauled up at least 6m (20ft). This is achieved by attaching a 20mm (3/4in) steel ring, 200mm (8in) in diameter to a tree or branch above 6m (20ft) in height. A rope, long enough to reach from the suspended bags to a trigger mechanism, is attached to the weight bag leaving a 2m (6ft) tail on the attaching knot.

Damo climbing the tree to attach a trap ring

Once the weight bag is handed up to the trap ring, the tail is tied off to the ring, tree or branch. This holds the suspended bag whilst a suitable trigger mechanism is constructed.

The boys hauling up the weight bags
while Damo is up the tree

To trigger the trap, a 6mm (1/4in) silver rope (bait rope) is attached to a bait then passed directly and tautly through the back of the trap to the trigger mechanism. A spliced loop on the end of this rope slides over the trigger rod. Any jerking or pulling of the bait will now dislodge the trigger rod, setting off the trap.

A trap should never be baited unless the trapper is totally prepared for a capture.

At the trap mouth, barricades of logs, sticks and branches should be placed so the crocodile cannot get down the side of the trap. This eliminates the common problem of a crocodile setting off the trap from the outside.

Always trigger the trap and re-set. This is critical to ensure the trap works effectively. If a crocodile escapes from an ineffective trap or triggers it from the outside, the crocodile may become TRAP WISE from a negative experience and NEVER be caught.

A lead-in bait should be placed approximately 1m (3ft) in front of the trap entrance/mouth. This is constructed of a strong nylon cord (2mm) attached to a stick or branch. A fist-sized morsel of food is secured to the cord so that the crocodile gets a taste for the bait and perhaps leaves a set of tracks at the trap site so the crocodile's size can be determined.

During the night the crocodile enters the trap, grabs the bait which dislodges the trigger, the bag is released pulling the trap mouth closed.

Once it realises it is trapped the crocodile tries to get out. The hemp strings break and the trap is loose around the croc. The sticks, which supported the trap, will be broken and knocked around without causing damage to the crocodile. No steel or damaging materials are used anywhere around the trap, sticks only.

The trap should be checked at first light. If a crocodile has been caught, a top jaw rope is secured and a blindfold is slid over the crocodile and trap. The head is then secured by tying ropes around the blindfold; this in turn secures the jaws together. Move the crocodile to an area where it is safe for it to be removed from the trap. Remove the crocodile from the trap and place it snugly into a crate ready for transport.

The beauty of soft mesh traps is utilizing the tools around you. A long skinny stick is perfect for securing top jaw ropes.  If the croc bites it he won’t hurt himself and I can quickly replace it.		I’ve been top jaw roping, restraining and transporting crocs on my own since the dawn of time.
It is always nice to have help. Dan helps me with this 15½-footer. Only the most experienced crocodile professionals are allowed anywhere near the croc. They can kill you through the trap, and constantly try to do so.

2. Gate traps

The gate trap is simply a modified version of the soft mesh trap. Instead of a weight bag and drawstring the trap utilizes a metal gate. The gate slides shut as soon as the croc attacks the bait at the back of the trap. It’s a soft mesh trap with a gate on it. The simplicity of the gate system means this trap is set up in half the time of setting up a traditional soft mesh trap. The downside is the clumsiness and bulkiness of the gate in the boat and through the mangrove mud. They work brilliantly on harder riverbanks and sandbars where there is no chance of the gate sinking into the grease-like mud.

The crocodile enters the open gate and moves towards the bait at the back of the trap. When the croc strikes the bait, the gate shuts behind it.

This 12½-footer was captured in the still of night, turned around inside the trap and was pressed hard up against the gate when I checked the trap at the first light.		Restraint and removal of the croc from the trap is exactly the same as a soft mesh trap.

3. Floating traps

I designed and engineered my first floating trap back in the year 2000. Over the years we continue to tweak and modify my design to ensure we’re constantly evolving with our increasing trap knowledge.

My current floating traps have been nicknamed ‘Floaters’ and they are unbelievably successful. They’ve never missed, never failed and constantly floor us with their record-breaking success.

They're constructed of aluminium for light weight and salt resistance, and stainless steel for durability. A sliding gate is propped up via a pin at the front of the trap. The crocodiles virtually swim straight to the bait at the back of the trap. As they strike the bait the gate slides shut.

Floaters have several benefits:

• No access to land is required;
• The trapper simply tows the trap to the location with a boat;
• The crocodiles swim straight in;
• The crocodiles can remain submerged in the trap for long periods without stressing and;
• Releasing an unwanted crocodile is as simple as opening the gate.
  
  

A trapped crocodile is towed to a workable bank.  The trap is dragged up so that the croc is exposed.		The gate is opened providing excellent access to a very, very angry crocodile just waiting to chomp.
A long stick is used to set one, two or three top jaw ropes.		I set the first one right behind those massive eye teeth, so there is no chance of it slipping off.
Safety, strength and maneuverability are essential so I set my second top jaw rope.		This crocodile is particularly aggressive so I set a third one enabling us to pull him out with total safety.
Crocodile extractions are deadly dangerous. As soon as we start to pull the big croc out he goes into a series of violent death roles.		The crocodile death roll is potentially the most powerful killing mechanism on earth.
Once he tires a bit from his death rolls, the team and I are ready to jump him.		JUMP! I jump straight onto the croc's head and hang on.
Then it’s up to the team to back me up immediately. They pile onto me and pin the big fella down. Piece of cake!		Once secured, Bindi and I quickly blindfold the croc so everyone can relax a little. Look at my girl - she’s such a chip off the old block.

The top jaw roping and restraint of crocodiles from floaters is extremely dangerous work, and only highly trained, certified personnel should participate. Unfortunately, we don’t always catch our target crocodile first; we’ll often capture the shy, smaller females and this trap design makes for very easy releases.

This is the third time we’ve caught this beautiful little sheila, so we’ve decided to drag her up on land rather then just let her swim out. Toby opens the gate but she won’t come out – she loves the trap.		We had to actually tilt the trap to make her leave.
Even then she casually strutted back down to her water, not all that phased.

Restraining

The simplest and quickest way to restrain a croc is to jump on it and hold it down. The amount of people power required is directly proportioned to the size, aggressiveness, fitness and stamina of the each croc. If you don’t, or can’t, control the head you will be maimed or killed. Once the croc has been jumped and successfully pinned down, no one gets off, or backs off. If a croc thrashes and someone backs off, a gap will turn into a weakness, and then the hold-down team could be in danger. If you give a croc an inch it will rapidly turn it into a mile.

In wet, greasy, muddy situations, all the people that can fit on the croc won’t hold it. Greasy crocs are unrestrainable with people power; these crocs I take on my own.

The mud is over waist-deep and extremely slippery. I’m better off working on my own; it’s less risky for everyone, except me. I’m easing myself towards this 13-footer's head, hoping he doesn’t death roll.		Once at his head I have to avoid any part of my body going forward around those teeth. From here I can secure his jaws without being chomped.
Have a go at this whopper! 15½ feet of sheer slippery power. Too risky for the team to jump on. Much safer for me to go it alone and call the shots.		Notice how I constantly keep my hands on the croc sensing for a buildup. I’m ready to move, I know that straight after the build-up comes the explosion of power and deadly chomps.
Using my body and hands I try to keep his eyes shut. This croc’s head weighs the same as my whole body.

Muddy crocs are slippery crocs and are dangerous crocs. I’ve spent half my life catching and restraining muddy crocs on my own. Although it looks hellishly dangerous (well, actually it is hellishly dangerous) it's safer because I don’t have the worry of someone slipping off or losing grip. On my own I can sense what the croc is going to do and therefore stay one step in front. If I sense a death roll coming, I’ll jump straight off a big croc, wait, then go in again. Crocs explode, tire, build up, and then explode, so I work in between explosions. However without a top jaw rope, any croc over 7 feet is gonna be impossible to work on my own. With one or more top jaw ropes attached to a tree, I’ve cut down the chance of the crocodile being able to reverse under me. Taking away one direction that the crocodile could go gives me the ability to come from that direction and work the croc.

Despite having good back-up this croc is way too slippery and I’ve got to go him on my own. I’m tugging on a small rope trying to get him to death roll. If he death rolls, that will be my queue to jump him. This croc is 12’ 3” but I’ve already got two good top jaw ropes on.		Beauty!  Death roll – now is my chance.
As he recovers from the death roll I jump him from behind.		My target is right at the base of his head. If I can’t control that head, I’m gonna be in trouble.
I pull his head hard up onto my chest and lock on.		Once the head is secured I stop him from death rolling by using my legs to hold up his.

The easiest place to restrain crocodiles is on nice dry sandy banks. When I’m trapping crocodiles I’m always on the lookout for dry, sandy, open areas close to the water. There’s little or no risk of a crocodile breaking free which makes it very safe for the hold-down team.

I can quite easily handle a 10-footer on my own on a nice sandy bank.		Note my back legs holding up his back legs so he can’t get pressure to death roll me off.
The whole time I’m mindful of head control. Their bottom jaws are the perfect shape for gripping.		Once the croc is ready for release I place a quick release rope around the jaws making it safer for me to jump off.
Have a go at Josh, he’s holding the release rope. This is a safety rope so I can dismount the croc without it swinging around and nailing me. Now that I’m clear, Josh will simply flick the rope off and the croc is free to leave.

Tackling a crocodile in the water is easily the most dangerous of all. Crocodiles can develop twice the power by utilizing leverage from the water; they also have twice the speed and are mostly invisible. Without a top jaw rope even a smallish crocodile would kill me easily. It’s virtually impossible to get away from a croc in the water – you’re in their territory, and they’re the masters. Once that huge, powerful, rudder-like tail hits the water the crocodile has doubled his strength and doubled the danger element. I only ever tackle crocs in the water if there is absolutely no alternative.

Have a go at those teeth.		Ideally I’d like to get at least one more top jaw rope on this croc before I jump him.
Strike! Luckily he bites the mangroves and not my legs.		I’m waiting, sensing when the croc is tired enough for me to make my move.
NOW! Two top jaw ropes and now I’m going for a blindfold.		Ropes and blindfold set.
“Hey Barry, get the boat over here!" Right now is when it’s good to have a very reliable mate.		While I control the head Barry launches himself onto the tail. This croc is 12 foot plus, and there’s no way we’ll lift his massive body into the boat.
Here’s a lucky break.  He death rolls, which enables us to get him in the boat. Have a look at the blood on Barry’s arms.  As the croc rolls, his teeth rip into Barry’s skin.		He’s so heavy he sinks the side of the boat.
GOTCHA! Once in the belly of the boat I should be able to hold him down. Job done!