SCIENCE LAB SPECIAL : SEE SAYING?

 

YOU See What I'm Saying? Dictionary could offer so much to chew on : A male saltwater crocodile approached a female saltie - as they're known in Australia - in the same enclosure at Australia Zoo. He snapped at her aggressively.

But then in a change of heart that wasn't what you'd expect from one of Australia's most fearsome predators, he appeared to think better of it.

''He went down under the water and started blowing bubbles at her,'' said Sonnie Flores, a crocodile researcher at the University of the Sunshine Coast who observed the interaction. '' It was kind of sweet. It was almost like he was blowing her a kiss.''

Trying to decipher what crocodiles are saying is the center of ongoing research by Ms. Flores and her colleagues to create the world's first crocodile dictionary.

Such a glossary would catalog different forms of crocodilian communication and unlock their meanings. If successful, it could even help prevent conflict between humans and crocodiles.

Like all reptiles, crocodiles and alligators don't possess a larynx and their vocal cords are rudimentary. And unlike those of most mammals, crocodilian lung muscles can't regulate the vibrations of those vocal cords.

But crocodiles and alligators have overcome their physical limitations to become the most vocal of all reptile species.

After studying recordings and video footage from captive crocodiles at Australia Zoo, and from wild crocodiles on a Daintree River and Cape York Peninsula in the northern state of Queensland, Ms. Flores has identified 13 categories of crocodile sounds.

These include growls, bellows, coughs, hisses and roars. But there are also nonvocal forms of ''speaking,'' like head slaps on the water, narial geysering [ when a crocodile dips its nose beneath the water and spouts water into the air], narial toots, and, yes, blowing bubbles.

A crocodile can even vibrate its back so that its scale-like scutes move up and down like pistons, spraying water. [ Anthony Ham ]