While they are billed as the world’s most dangerous bird, about the only thing cassowaries have in common with velociraptors is their age. They are thought to have evolved from animals that lived on the continent of Gondwana around 180 million years ago which loosely lines up with the Jurassic age.
Actually, they have other things in common with velociraptors such as they can leap around two metres off the ground and they have large dinosaur-like feet. It’s the feet you have to worry about, as that’s what they tend to attack with, but who wants to rile up a cassowary?
Oh wait, if you’re thinking two or three things in common with velociraptors is moving beyond a freaky coincidence of the natural world, you’d be right because there’s more.
One of the bird’s most distinctive features is the helmet-like ‘casque’ on its head and scientists from Victoria’s La Trobe University believe the casque on a cassowary shares many characteristics with dinosaurs.
In research earlier this year, they found the casque acts like a radiator or “thermal window” to help the large, flightless birds keep cool in hot weather.
And this “thermal window” explanation may provide a rare glimpse into the physiology of dinosaurs said Danielle Eastick, from La Trobe’s Department of Ecology, Environment and Evolution.
“Many dinosaurs also had casques, so it’s possible they too helped keep cool this way.”
Ms Eastick said the results “are quite compelling and it’s highly probable this is what the casque is actually used for.”
“It’s really exciting to think we may have solved a mystery that has baffled scientists for so long,” Ms Eastick said.
Using a handheld thermal imaging device, Ms Eastick obtained readings from 20 captive cassowaries, from Victoria through to northern Queensland and in different weather conditions.
The images showed that the birds released minimal heat from their casque when the weather was just five degrees and the greatest levels when the mercury reached 36 degrees.
“Just as humans sweat and dogs pant in hot weather or following exercise, cassowaries offload heat from their casque in order to survive. The hotter the ambient temperature, the more heat they release.”
“The casque has caused considerable curiosity and speculation for nearly two centuries and animal experts have proposed various theories, including that it’s a protective weapon used for fighting other animals or a means of attracting the opposite sex, but all are inconclusive.”
The upshot of this research, Cassowaries may just be velociraptors in disguise. Alternatively, they are a rather unique bird and with less than 4500 of the world’s second heaviest bird (after the ostrich) living in Queensland’s north-east, we should ensure they remain protected for generations to come.