The team which included the late Steve Irwin ("The Crocodile Hunter") also re-analysed archival data from the few crocodiles that have been satellite tracked whilst undertaking ocean travel. By overlaying the crocodiles' movements with surface current estimates they found that ocean swimming crocodiles showed a similar behavioural strategy when at sea.
One satellite-tagged crocodile a 3.84 metre-long male left the Kennedy River and travelled 590 km over 25 days down the west coast of Cape York Peninsula timing its journey to coincide with a seasonal current system that develops in the Gulf of Carpentaria.
A second crocodile a 4.84 metre-long male travelled more than 411 km in only 20 days from the east coast of Cape York Peninsula through the Torres Straits to the Wenlock River on the west coast of Cape York. The Torres Straits are notorious for strong water currents, and when the crocodile arrived the currents were moving opposite to its direction of travel. It waited in a sheltered bay for four days and only passed through the Straits when the currents switched to favour its journey.
According to Dr Campbell: "The estuarine crocodile occurs as island populations throughout the Indian and Pacific ocean, and because they are the only species of salt-water living crocodile to exist across this vast area, regular mixing between the island populations probably occurs.
"Because these crocodiles are poor swimmers, it is unlikely that they swim across vast tracts of ocean. But they can survive for long periods in salt-water without eating or drinking, so by only travelling when surface currents are favourable, they would be able to move long distances by sea. This not only helps to e
|Contact: Dr. Hamish Campbell|