It has been dubbed the most deadly avian on the planet. In fact, its lengthy, dagger-like digits caused the death of a man in Florida last year.
The cassowary, a big, emu-like, flightless bird, attracts biologists because of its unusual appearance. Its black iridescent feathery body, blue, turquoise, magenta neck, and horned crown or casque has been dubbed a “high-fashion dinosaur.”
“It stands a little more than a meter tall.” It’s rather hefty. Their bones are pretty thick. “They can definitely cause some damage,” said Chad Eliason, a staff scientist and postdoctoral scholar at Chicago’s Field Museum and author of a new report on the big bird published Wednesday in Science Advances.
“There are many stories about how their claws can be used to give dangerous kicks. They help you see that birds and dinosaurs are related.”
According to the San Diego Zoo, each of its three-toed feet contains a claw that may grow to be 4 inches or 10 cm long. This enables it to dispatch an attacker with a single kick. It can also sprint at up to 31 mph through dense jungle and leap up to 7 feet (2 meters).
High sheen
Researchers have now found out from studying the feathers of a dead bird what makes cassowary feathers so shiny and black.
High shinePaleontologist Julia Clarke, a professor at the Jackson School of Geosciences at the University of Texas at Austin and the paper’s lead author, said, “In living animals, we often take it for granted that we understand basic traits, like how colors are made.”
“We think we must know everything, don’t we? But in this case, we started out just being interested. Why do cassowaries have such a shiny coat?”
Unlike hummingbirds and crows, whose feathers are glossy due to barbules, the cassowary’s feathers are shiny due to the rachis, which is the spine of the feather, rather than the barbules.
Since the barbules on cassowary feathers are not particularly dense, the rachis receives more light than in “thick-feathered” animals, allowing it to truly shine.
“Compared to other birds, the shine is in a whole different part. “If you think of a feather as a tree, the shine is in the trunk, not the branches,” said Eliason.
The three types of cassowary are native to parts of northern Queensland, Australia, and New Guinea. They eat fruit for food.
The study showed that the cassowary’s unique way of making its feathers shine would have developed slowly over time, with an ancestor bird losing its barbules and the cassowary getting a bigger feather shaft in the middle.
Eliason hypothesized that flightlessness may have provided cassowaries with more evolutionary space to develop their peculiar feather shapes.
“The need to fly is a very powerful stabilizing force on wing shape,” said Eliason.
“Losing this constraint, the need to fly, could result in new feather morphologies that produce gloss in a way that flying birds might not.”