Cassowary calls as low as they go, according to a report in New Scientist, 15 Nov 2003, p17. Cassowaries are big birds that live in the rainforests of Papua New Guinea and Queensland, Australia. They make distinctive, booming low pitched calls. Two American biologists recorded cassowary calls and found they make sounds as low pitched as some whales, going down to 23Hz near the lowest end of human hearing range. Such low pitched sounds travel well through the forests enabling the birds to communicate over longer distances than higher pitched calls. The researchers suggested the bony crests on the birds’ heads enable them to receive the low pitched calls. The crests are covered with keratin and have many air pockets. One researcher, Josh Jones from Scripps Oceanographic Institute, San Diego, who also studies whale calls commented “It’s like a big microphone stuck on top of this animal’s head.”

Editorial Comment: Generating and receiving meaningful sounds requires intelligent design and engineering. Ask those who design and build sound systems for large outside venues. Some dinosaurs have been found with large bony crests on their heads. These are often portrayed as armour plating or weapons for dinosaur duels in the “struggle for existence” that is supposed to drive evolution. Maybe they had the same function as the cassowary’s head gear and we need a new TV series “Talking with Dinosaurs”? (Ref. cassowary, sound, communication)