Today’s factismal: There are (or were) flightless birds on every continent.
Diogenes and Plato once got into an argument about how to define man – what set him apart from the other animals? Was it his brain? No, because other animals have them (and the Greeks didn’t think that the brain was important). Was it his buildings? No, because other animals make nests and other constructions. Was it his fidelity? No, because other animals mated for life. Finally, Plato decided that the way to define man was as a “featherless biped”. The next day, Diogenes strode up to Plato, threw a plucked chicken at him, and said “Behold! A man!”
Something like this happens when you ask people about what sets birds apart. They’ll point first to the feathers and beaks; then you point out that dinosaurs had feathers and that platypodes have beaks, they’ll say that a bird is a feathered animal that can fly. The only trouble is that, like Plato’s definition of man, it doesn’t work all the time. That’s because there are more than 40 species of flightless birds living today and there were even more in the past. As a matter of fact, flightless birds have lived on every continent and are now found on every continent except Europe!
But why would a bird give up the ability to fly? In some cases, such as the penguins, it is because it made them better at hunting their food. The penguin’s wings evolved into flippers that help speed it through the water and allow it to make razor-sharp turns as it speeds after krill and small fish. In other cases, such as the Cretan owl, it is because the bird lived on an island with no other major predators, so the energy used for flying was better put to use in making baby birds. And in some cases, such as the cassowary, it is because the bird grew so big that it didn’t need to fear the predators any more.
And boy is the cassowary big. An adult cassowary stands as tall as an adult human, but weighs just 130 lbs. Adding to its imposing presence is the brightly colored crest atop its head that may help them communicate or perhaps it is a battering ram that they use as they run through the dense rainforest that they call home; we still aren’t sure what the casques’ function is. What we are sure of is that they are mostly frugiverous but will cheerfully gobble down a snake or bug if it comes their way. Despite their size, they are fast; they can run up to 50 mph through the rainforest, and can kick their enemies with blinding speed.
Of course, this just scratches the surface of what is known about cassowaries and flightless birds in general. If you’d like to learn more or to report sighting a bird (flightless or not), then head on over to the WorldBird website and help them as they try to discover where every bird in the world lives: