Cassius may be the world’s largest living crocodile – but his keeper assures us he’s an absolute sweetheart with “dreamy” eyes.
The good boy, who lives at Marineland Melanesia wildlife zoo on Green Island in Australia, holds the record for largest crocodile in captivity (living).
Cassius was first awarded his record on 1 January 2011, when he was measured in at 5.48 m (17 ft 11.75 in). [Fun fact: that’s as big as the Statue of Liberty’s face!]
He’s an Australian saltwater crocodile, which is the largest and most fearsome of the species.
The crocs can live for more than 100 years and grow to be up to 7 m (23 ft) long and weigh more than 1 tonne (1.1 ton).
Toody Scott, who works at the Marineland Melanesia Crocodile Habitat for his grandfather George J Craig, is personally responsible for Cassius’s care, and they get on famously.
He told us: “His eyes are so big and dreamy you could get lost in them forever.
“He has a gentle nature unlike most but we have to remind ourselves he can be cunning as a croc and the best way to win his heart is through his stomach, after all we are in ‘croc country’ and it’s always best to stay ‘Crocwise’.”
Toody believes Cassius could be as old as 120, although there’s no way to know for sure.
Based on the growth of crocs they’ve had since birth – who at 4.5 m are nowhere near as big as him – it’s estimated Cassius was born in 1903.
Toody explained: “As crocodiles get larger than 5 m, growth rates seem to slow to as little as 1 cm per year and in many instances the crocodile may stop growing.
Using this data, we estimate Cassius’s birth year was 1903.
Cassius is the largest crocodile to ever be caught alive in Australia.
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He was originally captured from the Finniss river, south of Darwin in the Northern Territory of Australia in 1984.
He was transferred 3,200 km (1,988 miles) by truck to the zoo in 1987 – and it was all for his own safety.
Cassius had become a target due to attacks on small fishing boats and rumours he was eyeing up the cattle.
It’s possible he has grown even bigger since his record was awarded in 2011, but no one has dared get close enough with a measuring tape.
Toody said: “It’s very possible Cassius may have grown bigger since 2011, however we have not attempted to remeasure him.
“We may attempt this in the near future to provide some insight into growth rates of large crocodiles or of course if his record was being challenged.
“This would also be an opportunity to hypothesize how much of Cassius’s tail and snout is missing - common injuries in Estuarine [saltwater] crocodiles from territorial disputes with other crocodile from his days living in the wild.”
Cassius’s missing snout and tail were never factored into his record-breaking length, but it’s thought that if he was fully intact, he could be as much as 15-25 cm longer.
Since entering the record books, Cassius has been living the life of luxury as the zoo’s star attraction.
Toody said: “Becoming a Guinness World Record holder certainly shot Cassius to ‘Croc-Stardom’.
We often get people visiting from around the world to say ‘G’day’ and children from all over Australia that want to come back just to see Cassius the living dinosaur.
Cassius is one of 16 crocs living at Marineland Melanesia, a small habitat that takes in “problematic” crocodiles that have been deemed a threat to humans.
Some of the males are as big as 4.5 m, but still pose no competition for Cassius, who is around 1 m longer and 500 kg heavier than the rest.
Toody’s grandfather George established Marineland Melanesia in 1971 after spending 18 years perfecting the craft of safely capturing and relocating rogue crocodiles to help prevent attacks on villages.
Now 93, he’s spent the last 70 years searching for the largest crocodiles on the planet, and to this day, Cassius is the biggest he’s ever laid eyes on.
As crocodiles are cold blooded reptiles, they don’t require large amounts of food in captivity, and even though Cassius is huge, he only eats around 4-5 kg of food a week.
Cassius will be offered small pieces of fish and chicken every day for a bit of behavioural enrichment, and then once a week he’ll be served up a whole large fish, chicken or another big piece of meat.
His keepers carry out several tasks to make sure Cassius is comfortable in his environment, like checking the water temperature and quality.
His enclosure needs to be kept as quiet as possible so Cassius can get his beauty sleep between his turns in the spotlight.
Toody said: “He is often featured in our public presentations, demonstrating a crocodile’s ability to track prey under water using sensors located on their snout.
“Submerged and honing in on slight movement made with a piece of food, he will snap into action in a demonstration that recreates natural instinctual hunting and feeding behaviour.”
But don’t be fooled by this, as Cassius is a big softy at heart.
He once became a surrogate dad to a baby croc named Zina who hatched out of her egg and made her way into Cassius’s enclosure.
The keepers thought they had removed all the fertile eggs from the enclosure next to Cassius’s and were terrified that he’d eat the baby after it wandered into his pen in 1993 – something that his species does at times in the wild.
But to everyone’s surprise, Cassius took Zina in as his own and raised her to adulthood over the next 15 years, often giving his own large pieces of food to her instead of taking them for himself and swimming around with her sitting on his head.
As she grew older, it was clear Zina was the boss as she’d often ferociously head slap him in a display of dominance.
“Needless to say, Cassius was relieved when Zina was relocated and paired with our second largest crocodile of 4.5 m,” Toody said.
“Cassius now prefers to spend his days self-partnered.”
The saltwater crocodile went from being almost extinct in the 1970s to growing back to large and widespread numbers, but Toody says it’s still important for us to protect them.
He explained: “Crocodiles once hunted dinosaurs and are an apex predator. They’re crucial in maintaining biodiversity and have provided a balance to ecosystems for millions of years and have earned their place in nature.
Threats that now face all crocodilians include destruction of habitats, urban development, revenge killings, and drownings in fishing nets.
“And with global temperatures generally on the rise, species like sea turtles and crocodiles - whose gender is determined by embryo temperature - this may create an imbalance between males and females of the species.”
Cassius recently celebrated his birthday – a day chosen for him by the zoo – and was treated to his annual health check by Professor Sally Isberg, Managing Director of the Centre for Crocodile Research… as well as a large tuna head for lunch.
Assessments like this are done with a very hands-off approach, as putting a croc in restraints can cause trauma and stress.
Cassius is such a beautiful, big, magnificent boy and he’s obviously got such a vivid history to tell. - Sally Isberg
“He’s been here now for over 35 years, but he was taken from a situation in the wild where, I feel, that he obviously wasn’t very happy.
“He was attacking boat engines and when you talk to the crew here at Marineland Melanesia, whenever there’s machinery at work around here he also exhibits funny behaviour, so it makes me think that he just really reacts badly to having machinery around him.
“Now, in the wild, that [resulted in] him attacking boat motors whereas here he’s fitted in really well. He’s a happy, healthy boy, he has such a personality, he gets called over from one side of the pen and he happily wanders over.
"He’s got an amazing relationship with George Craig and the rest of the crew here and he’s just an absolutely fascinating character."
As part of her annual health check on Cassius, Sally measured the stress levels in his poo (he’s super chilled out), checked the quality of his water and the type and quantity of food he’s being fed.
Sally carries out health checks on all the crocs at the zoo, but she does admit Cassius is her favourite.
“He is the star of the show,” she said.
“To me, crocodiles are just one of the most remarkable species on the planet.
“They are just amazing animals, they are perfectly suited to their environment but they do get a bad rap. They are apex predators and when people put themselves in the wrong position, [crocodiles] are often the ones that are blamed for the outcome, which could be fatalities or injuries.”
She said humans are the biggest threat to crocodilians, with people taking over their natural habitats to make homes of their own.
Sally added: “This is why having places like [Marineland Melanesia] are so important to be able to educate people on crocodiles.
“People get to interact with them face-to-face, up close, and be educated on their true magnificent beauty.”
Cassius reclaimed his record from Lolong, who took it when he was was captured in 2011 in Agusan del Sur, Mindano, Philippines.
But Lolong remains the largest crocodile in captivity ever.
Also a saltwater crocodile, he was 6.17m (20 ft 2.91 in) long and weighed 1,075 kg (2,370 lb). He died on 10 February 2013.
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