There were already many anecdotal accounts of large crocodiles sighted far out at sea, but nothing confirmed. Now, for the first time, using sonar transmitters and satellite tracking, scientists now find that saltwater crocodiles actually do ride surface ocean currents for long-distance travel, enabling them to voyage from one oceanic island to another.

"Because these crocodiles are poor swimmers, it is unlikely that they swim across vast tracts of ocean," said researcher Hamish Campbell, a behavioral ecologist from University of Queensland in Australia. "But they can survive for long periods in saltwater without eating or drinking, so by only traveling when surface currents are favorable, they would be able to move long distances by sea."

Crocodile river travel

Working at the remote Kennedy River in northeastern Australia, the team of scientists Ñ which included the late Steve Irwin, "The Crocodile Hunter" Ñ tagged 27 adult seawater crocodiles with sonar transmitters, employing 20 underwater receivers deployed along a 39-mile-long stretch of the river (63 km) to track the reptiles' every move for more than 12 months. They found both male and female adult crocodiles undertook long-distance journeys, regularly traveling more than 30 miles (48 km) from their home area to the river mouth and beyond into open sea.

The scientists also discovered the "salties" always began long-distance travel within an hour of the tide changing, allowing them to go with the flow. They halted their journeys by hauling out onto the river bank or diving to the river bottom when the currents turned against them.

(LiveScience website)