Chris Calcino, The strange world of crocodile hairballs and the Queenslanders who collect them, ABC Far North, 10 March 2024
Anyone with a pet cat will have borne witness to the nauseating process of hairball expulsion.
They grunt, squeeze, dribble and snort until a repulsive mass of wet, undigested fur plops onto the carpet.
Now, imagine witnessing a crocodile in the same act.
It turns out crocs, like cats, also hock up hairballs – or bezoars as they’re known – and a handful of Queenslanders collect them.
The crocodile hock
Townsville man Marc McConnell first stumbled across a bezoar while conducting drought resilience field work with NQ Dry Tropics, a not-for-profit natural resource management group.
What he initially thought was a small mammal carcass turned out to be a tightly packed wad of hair about the size of a softball.
“The cogs start turning in your head and then you’re like, ‘OK, there’s a very large crocodile nearby that’s just had a feed’,” he said.
“That sort of memory sticks with you.”
Most people might baulk at the thought of touching something that had been festering in a reptile’s guts for several years.
Not Mr McConnell.
He took it home, gave it a rinse and made it the centrepiece of a growing collection of natural oddities.
“I don’t collect exclusively crocodile hairballs, but I certainly have a couple on my person at most times,” he says.
“You could throw it against the wall and catch it, and it would still hold together.”
Big lizard lunch lurch
Mr McConnell described his first bezoar as a “tight mat of feral pig and wallaby hair” — but there can be plenty of variation in their composition.
John Lever owns Queensland’s first commercial crocodile farm, has held positions with the CSIRO and wrote the National Crocodile Program for Papua New Guinea.
“Crocodiles, strangely, can’t digest hair,” he explained.
“They can digest feathers and they can digest meat and bone, but the acid they produce in their stomach doesn’t affect hair.
“So, the hair retains and eventually gets tangled up and starts to form a ball.”
During his time in PNG, Mr Lever found one large bezoar and sent it away for forensic testing at a university in Port Moresby.
“They found several species of flying fox, wild pig bristles and hair, Papuan wild dog, possums and cuscus … and human hair … both Caucasian and Melanesian,” he said.
“This crocodile had been around for a fair while … and being opportunistic feeders, he’d had his munch on a couple of people as well.”
The researchers were fascinated by the findings.
“It was like a diet list of what the crocodile had eaten for the last 40 years,” Mr Lever said.
“All the rats and rodents you could ever think of, they were inside the croc.”
The Central Queensland croc farmer said the biggest bezoar he ever found was about the size of a football inside the decaying corpse of a croc at Kakadu in the Northern Territory.
Fussy eaters
Bezoars aren’t a big issue at Mr Lever’s Koorana Crocodile Farm, since the inhabitants have short life spans and any wild pigs they eat are skinned.
“Our crocodiles only grow to three or four years of age before we harvest them, so there’s no time to accumulate a lot of hair,” Mr Lever said.
However, there have been real problems with rabbit fur.
Mr Lever thought he was onto a winner some years back when he brokered a deal to source waste product from New South Wales rabbit farms.
“We got all the rabbit heads and rabbit feet that are just thrown away or buried or whatever,” he said.
“We got them at a good price.”
Unfortunately, his reptiles were fussy.
“The crocodiles didn’t like the texture of the fine hair in their mouth, for a start, and spat it out most of the time,” Mr Lever said.
“The little bit that was left in the ponds blocked up every drainage pipe we had – so that fine rabbit hair became a complete nuisance to us.”
‘Fantastic souvenir’
It’s not just pig, possum and people pelt getting heaved up on the riverbank.
Mark Norman spent decades working as a crocodile safari guide on the Proserpine River but had only ever seen a bezoar in a display cabinet.
His dream of discovering one in the wild finally came true while pursuing a 4.5-metre dominant male in his usual haunt.
“I got up really close and he backed off into the water beside us and went under,” he said.
“That’s when I noticed four of these furry black balls that he’d just coughed up on the bank.
“What a fantastic souvenir – I’d been looking for one for years.”
Mr Norman scooped them up with a net, took the best one home and gave it a rinse.
He used it as an interpretive tool on tours and, in retirement, it now takes pride of place on his mantelpiece.
But hair wasn’t all he found.
“This particular croc had also coughed up two plastic iced coffee bottles that had been floating on the river,” he said.
“And when I had a proper look, the bottles were full of pig fur.”
Roots and all
The Queensland Museum has two of the hairy conversation starters on display – one of which is a smooth, whitish ball that looks rather like a loaf of sourdough bread.
Herpetology collection manager Andrew Amey speculated that the variation in consistency might be due to the length of time in the digestive tract.
“Perhaps the smoother object was in the stomach for longer and the fur has been abraded smooth,” Dr Amey said.
Visitors to the museum’s discovery centre can get a hands-on experience of this utterly bizarre natural phenomenon.
“As it’s not an official collection item, members of the public are able to interact with this particular object when it is in use,” Dr Amey said.
There might be scientific value in these objects, but budding collectors be warned.
Back in Townsville, Mr McConnell’s decision to keep bezoars around his home doesn’t appeal to as many potential visitors as one might think.
“Generally [the reaction is] … that sounds bloody disgusting, and your house sounds like something from a horror movie,” he said.