Tiger sharks travel thousand miles to find dates

Tiger sharks journey thousands of miles to find their dates in exotic locations, a new research that documents the longest tiger shark track suggests.

One tiger shark, named Harry Lindo, travelled more than 44,000 km (27,000 miles), the longest track distance documented for a tiger shark, the study said.

"It is truly remarkable," said the study author Guy Harvey, a renowned fisheries ecologist.

The study was led by co-first authors James Lea and Brad Wetherbee and senior author Mahmood Shivji from the Nova Southeastern University's (NSU) Guy Harvey Research Institute in Florida.

Tiger sharks are among the largest and most recognisable sharks on the planet, yet many of their habits remain mysterious because they are long-distance travelers that are hard to track.

For this project, the tags the team attached to sharks near Bermuda lasted in many cases more than two years, and in some cases more than three years, sending satellite position data each time an animal surfaced.

Long believed to be mainly a coastal species, the tiger sharks, in fact, made more than 7,500 km, round-trip journeys every year between two vastly different ecosystems -- the coral reefs of the Caribbean and the open waters of the mid-North Atlantic, the study showed.

The researchers were able to show that adult male tiger sharks in the Atlantic repeatedly spend their winters in Caribbean island locales including the Bahamas, Turks and Caicos Islands and Anguilla.

Then, during summers, they travel far into the North Atlantic, often more than 3,500 km and as far north as Connecticut, though well offshore in nearly the middle of the ocean.

What makes the tiger sharks so committed to particular areas is still an open question. At the south end, the story may be fairly simple.

Female tiger sharks are common in the Caribbean in winters, so the Caribbean may just be the best place for male tiger sharks to find dates, although this is just an educated guess, the study said.

Why they go so far north is more complicated.

"There's got to be something really good up there to make the sharks undertake such massive, repeated swims, but exactly what is a puzzle," Shivji said.