Sepik croc a super surfer

THE salt water crocodile surfed waves across kilometres of ocean to “colonise” South Pacific islands, including Papua New Guinea, scientists have learned.
The discovery explains how the world’s largest living reptile came to be found on numerous islands. and river mouths like the Sepik and Fly rivers, separated by huge stretches of the Pacific Ocean.
It may also account for reports of large crocodiles being sighted far out to sea by many Sepik coastal villagers.
The formidable estuarine, or saltwater crocodile, whose habitat extends over more than 10,000 square kilomeres of the southeast Pacific, lives mainly in rivers, mangrove swamps and estuaries.
Scientists have long wondered how estuarine crocodiles manage to travel so far when they are poor swimmers.
The answer, according to new findings reported in the British science publication Journal of Animal Ecology, is that they surf.
Australian researchers in neighbouring north Queensland tagged 27 adult crocodiles with sonar transmitters and tracked their movements over the course of a year.
Satellite data on tracked crocodiles were also analysed.
The scientists found that both male and female crocodiles undertook long-distance journeys, often travelling more than 50km from their river homes to the open sea.
Among the team was the late Steve Irwin, the crocodile-hunting wildlife expert and TV personality who was killed by a stingray in 2006.
The evidence showed that, like surfers catching waves, the crocodiles rode the ocean currents to cross large areas of open sea.
One 4m male, travelled a distance of 410km in 25 days, timing its journey to coincide with seasonal currents.
A second, measuring over 16ft, covered more than 255 miles in just 20 days. Again, the crocodile utilised fast-moving ocean currents to reach its destination.
The researchers speculate that the crocodile used their ability to surf the ocean currents to fan out throughout the southeast Pacific. Populations of the giant reptiles are found in PNG, east India, Sri Lanka, southern China, Thailand, the Philippines and Sunda islands (Sumatra, Java, Borneo, Celebes, and Timor), to northern Australia, the Solomon Islands, Vanuatu and Fiji.
Dr Hamish Campbell, from the University of Queensland, wrote in the journal: “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.”