SATELLITE TRACKING

Introduction


How do you know if the animal you are looking at is the same one you saw last year, last month, last week or even yesterday? Well, you could mark the animal in some way with a bright, visual tag. This may work but often depends on getting close enough so you can read the tag or markings. The marking or tag may also make the animal more visual to predators, alter behaviour or even disrupt the social structure of a group.

Radio tracking is a good way of keeping tabs on a particular animal and is often used in short-term movement studies. These radio transmitters are small and discrete so they do not disrupt the activity of the animals. However, they still have a major drawback in that the person following the animal with the transmitter attached still has to remain close and this in itself may affect the normal behaviour of the animals being observed.

Satellite transmitters are not new to science or to animal managers. They have been successfully used on a number of terrestrial mammals, marine mammals such as Dugong and Elephant Seals, several species of marine turtle and even a Great White Shark. The advantage of satellite transmitters over other forms of tracking is that no one has to be anywhere near the animal being tracked. It's all done from space so the animal's normal behaviour is not affected.

Australia Zoo in partnership with the Queensland Environment Protection Agency and the University of Queensland have started on a long term project using satellite tracking technology to find out about the secret life of one of the worlds largest predators, the Estuarine or Saltwater Crocodile.

After over 60 million years being unchanged on this planet, you think that we would know all there is to know about crocodile's wouldn't you? After all, they all live in water, are carnivores and lay their eggs either in mounds or in vegetation nests. How little we actually know! As you will see in the descriptions below, the satellite tracking of the Saltwater Crocodile is revealing how complex an animal they really are and how little we actually know about them.



NESBIT RIVER CROCODILE TRACKING

 

Introduction

During 2 weeks of trapping crocodiles in the Nesbit River, Far North Queensland:

  • 10 crocs captured
  • 2 crocs recaptured

A total of 12 captures by:

  • Ground crew team leader - Bob Irwin
  • Australia Zoo team - Brian, Trevor, Frank, Wombat
  • Dr. Mark Read
  • Brazakka - Chopper Pilot
  • Steve Irwin
  • Film Crew - John, Justin, Craig

Crocodiles captured and Reports:


Synopsis by Steve
During the month of September 2003, me and my team from Australia Zoo and my friends from the Queensland Parks and Wildlife Service captured and released some huge Saltwater Crocodiles in Cape York Peninsula. The aim of this project is to determine the movement patterns and spatial utilisation by adult Saltwater Crocodiles, and we plan to do this by attaching satellite transmitters to these animals and then follow their movements by accessing the data from the computer. In 2003 we completed the trial phase of this world-first project and successfully attached six satellite transmitters to crocodiles ranging in size from 2.65m to over 5m. The information we have collected in this short time is already starting to redefine how we think about the movements of large crocodiles, and its got the crocodile world quite excited! A summary of this project and information on the movement patterns of these crocodiles can be viewed at www.epa.qld.gov.au and link to the 'croc wise' site and follow the prompt to the satellite tracking research.

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Transporting a floater to the very top waterhole


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Lowering the trap


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Steve securing the trap


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"Brazakka" captured in a floater, top hole, 19/10/03. 15' long, plus, tail missing. Both front legs bitten off.


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Very, very powerful croc. Hard to restrain.


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Both front legs bitten completely off. Old injuries.


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Only 7 single scutes left on his tail. Old injury.


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Best head and teeth of all the crocs captured


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Complicated release. Brazakka barrels Frank.


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His jaws open so powerfully that ropes go flying.
Notice the two airborne pieces of rope.


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Flick the last rope off


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Free


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Extremely athletic croc - obviously doesn't
need front legs to attack Steve


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Mark, Steve and "Brazakka",
the crocs namesake


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And away he goes. It was incredibly important to catch and release this big bloke as his waterhole had a couple of vantage points where criminals could shoot him. Steve and Trevor found a well used semi-permanent camp full of bullet shells and having an illegal Barra net. We taught"Brazakka" to avoid people at all costs - probably saving his life.

All up this project was completed in two weeks and the Australia Zoo team and Dr Mark Read could not have achieved as much so quickly without the services of "Brazakka" the ace helicopter pilot. He enabled us to shift traps, crocs and people to areas that are virtually inaccessible.

"Brazakka" the crocodile being such an obvious target for criminals probably owes his life to the skill and commitment of the overall team and particularly his namesake.


 

NESBIT


This is the river system's namesake and what an extraordinary crocodile. All my life I've wondered about ocean going crocodiles and for the first time in my life, I caught a crocodile encrusted in Barnacles, which means he travels and spends a lot of time in the sea. His satellite transmitter has now given us humans a glimpse of the "True" life of ocean-going crocodiles. He actively hunts, basks, swims the Coral Sea within the Great Barrier Reef in the Pacific Ocean.

Absolutely cutting edge scientific information from Nesbit will be utilized to better understand and above all manage our magnificent crocodilians.


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'Nesbit' captured in Bob's Big Blue Trap 15/10/03.
15' plus, large amount of tail missing


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Huge pieces of his tail have been bitten off


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Nesbit fought so violently that he snapped a
12mm rope in a death roll. Stevo securing him
with more ropes prior to attaching the transmitter.


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Attaching the transmitter


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Transmitter attached


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The team readying for release


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All the ropes off, team ready to dismount and RUN


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Steve calls "GO" and everybody bolts!!!


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Very awkward/dangerous release. Steve swings
into the trees and snaps his finger on a rope
as Nesbit charges for the water. Yowch!


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Ritualised combat. Immediately after his
release another male (probably Bob) started
a fight. An excellent battle of two dinosaurs
right in front of us.


 
 

BANANA HEAD


This crocodile has provided us with the most impressive information we've collected for translocated crocodiles so far.

He's in the 10-12 foot male range, which is the majority of the problem, nuisance or rogue crocodiles here in Queensland. So we decided to transport him by chopper over 50 kilometers away from his home to explore the "Homing Instincts" of this amazing species.

Not only did Banana Head make it home, he traveled the last 3 kilometers over land. Yep!! He walked 3 kilometers across a very, very thickly vegetated strip of land to get home.

"Good work, Banana Head, we love you, mate!"


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'Banana Head' captured in Bob's Big Blue Trap
- 14/10/03.
11' odd long. Transmitter attached.


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Transmitter attached between nuchal scutes


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Hot Dog wrap and lifting net ready for transport


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Looking perfect for the lift


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Banana Head was taken 50kms south as a
trial of crocodile's homing instincts


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Steve keeping an eye on him during the flight


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Steve removing the Hot Dog Wrap


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Only the jaws and blindfold to go


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Free


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Straight into the sea. Banana Head was
perhaps the most important crocodile we tracked.
Being a young 10' - 12' male made him the
perfect choice for relocation. This size is the
majority of Fair Dinkum Nuisance crocodiles
around people, so we flew him 50km south
of his waterhole and released him.


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Nesbit River croc hole


 
 

BOB


This very naughty crocodile is my Dad's namesake. We first saw Bob the day before we caught him, immediately after the release of Nesbit. He obviously thought that after Nesbit was released that he may have been able to beat him in a fight. Once again, for the first time in all of our lives, (crikey, so many "firsts" during this mission), we witnessed a huge fight called "ritualized combat" between Bob, the aggressor, and poor old Nesbit, who was still a little confused after his capture and release. The funny thing is when you're a croc, "size does matter", as it was actually Nesbit who finally appeared to win the fight.

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Bob eyes off Nesbit after his release

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Nesbit triumphant over Bob despite
his capture and release


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'Bob' captured in Bob's Big Blue Trap - 16/10/03.
14' long and solid. Hits on his head and back
from fighting Nesbit yesterday (15/10/03)


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Top jaw roping


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Jumping him


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We had to blindfold him, get him in a boat and
take him to a safe area for transmitter attachment


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Out of the boat and dragged up to some shade.
Very heavy and solid for his length.


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Secured in the shade ready for
Mark to attach transmitter


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Bob's namesake and Steve


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Protect the transmitter at all costs.
Death rolls were the hardest thing to stop.


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Steve kisses Bob passionately.
This team really, really loves their CROCS.


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Good release and dismount


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Steve and Mark admire the transmitter
and the glory of Bob


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After the release Bob is disorientated


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Steve show Bob the water


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Sexy transmitter Bob! He hits the
water and bolts


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Very happy team


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Bob was recaptured on 19/10/03
in floater at Deep Hole. Notice the foliage to
camouflage the trap.


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"Come on Bob out ya get"


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"Isn't he gorgeous"


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And away he goes. Bob was definitely the
"Ratbag" of the waterhole. He demonstrated to
us that recapturing wasn't going to be out of
the question. In one year the transmitter
batteries will fail and we'll return and remove
the transmitters - and catch up with our old mates.

This was the greatest crocodile learning curve of our lives. All the knowledge we learned here and in Lakefield National Park two months ago will be critical to the recapture of all these big blokes with transmitters.

We have only now witnessed two separate recaptures of very large male crocs within days of being first captured.

Although it is unlikely that the transmitters hinder these fellas at all - it's still going to be "JOB DONE" when we have the transmitters in our hot little hands and the crocs back in the drink.


 
 

GOLIATH


Here he is! Easily the largest crocodile any of us has ever seen. This crocodile was so massive, death rolled so violently, tried so hard to wipe me out with his tail, (which I've never seen a crocodile do before), and has so much raw power, energy and endurance all we could do was look at him in awe and take measurements.

Although he's probably a few inches shorter than Supercroc, Goliath by name and by structure. We caught him on a sandbank with absolutely no chance of being able to get him to our camp and the mechanical advantages of 4WDs and winches and swivels, so we taught him a very valuable lesson about the power of people, collected some DNA, measured him and released him. By capturing him he has learnt to never approach or hang around when people are present. This will undoubtedly ensure his life is not taken by a wildlife criminal with a gun.

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"Goliath" captured on sandbank in that
camouflaged floater behind Steve 22/10/03.
Whopping 16'1", plus, tail missing. Estimated
around 17' but massive. Easily the
largest croc captured


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Death roll on capture. Very aggressive,
never backed off from the trap gate


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We were able to drag him up the bank


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Trevor kept the A-frame via a pulley


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Measuring his head


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Steve measuring him in sections


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As well as his tail missing he had a back
foot ripped off. Old injury


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The HEAD


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Have a go at the size of him


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The ropes flicked off easily


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Steve turning him towards the water


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"Here's ya water mate!"


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He's off


 
 

Supercroc


The longest crocodile I've ever seen. Here is the crocodile that I set out to capture or at least see many years ago. This is one of the true giant crocodiles of our modern age. The importance of this crocodile is to highlight the death and destruction of these magnificent Kings of their domain. Since World War 2 there has been an outright war on large crocodiles. Sport Shooters, Trophy Hunters and downright wildlife perpetrators/criminals have always targeted the largest of all species from Elephants to Tigers to Sharks to Crocs. It has been the perpetual hunting and killing of the biggest trophy animal since guns were invented that has had a catastrophic effect on the world's wildlife.

Supercroc has granted me the opportunity to highlight to the ENTIRE WORLD the importance of respecting the biggest of a species, not killing it to stick it's head on a wall or mantle piece.

Here are the animals we need to protect the MOST. The grandest animals in the eco-system which have endured the tests of time and carry the genes of tenacity, cleverness, grandeur and above all the instincts to avoid people.

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"Supercroc" captured in floater at Deep Hole
21/10/03. 16'2", plus missing part of his tail.
Estimated to be well over 17 feet long,
the longest croc captured

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4 blokes pinning a 17 footer. Whew!


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Steve attaching a transmitter


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Very long slender Croc. He smashed
our trap so badly it was unusable


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Stevo's new bottom jaw release technique


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"RUN"


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The longest Croc Steve's ever caught SO FAR!


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Supercroc heads straight back to his deep hole
where he stayed until we left the area


Download: Determining the movement patterns of adult estuarine crocodiles using satellite telemetry - provided by Dr Mark Read (EPA).

Determining the movement patterns of adult estuarine crocodiles using satellite telemetry

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