The croc came back

Natural History, Dec, 2007 by Brendan Borrell

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Saltwater crocodiles aren't known for their sentimentality, but they are prone to bouts of homesickness, according to a new study. Conducted with the help of the late Steve R. Irwin--the "crocodile hunter"--the study shows that displaced "salties" will travel as far as 250 miles to return to their home estuaries.

Craig E. Franklin of the University of Queensland and several colleagues, including Irwin, captured three large male crocodiles on the Cape York Peninsula in Australia's northeast tropics--no mean feat considering the beasts weigh more than 500 pounds apiece. After securing satellite transponders to the crocodiles' backs, the team helicoptered them thirty-five, sixty, or ninety miles away from their capture sites.

After lingering in their new environs for as long as three months, the crocodiles made a beeline along the coast for their old haunts. The endurance champ--a fifteen-footer who'd been airlifted across the peninsula--swam 250 miles clear around the coast. He covered as many as nineteen miles in a single day, belying the notion that crocodiles are burst swimmers and cannot exert themselves for extended periods.

The study also shows that salties are gifted navigators; Franklin speculates that they, like their closest relatives, birds, use clues from the sun and Earth's magnetic field, as well as their senses of sight and smell, to find their way. (PLoS ONE)