The link has a video showing part of the battles, pretty cool.
http://news.bbc.co.uk/earth/hi/earth_ne ... 318182.stm
A BBC natural history crew has filmed the "humpback whale heat run", where 15m long, 40 tonne male whales fight it out to mate with even larger females.
During the first complete sequence of this behaviour ever captured, the male humpbacks swim at high speed behind the female, violently jostling for access.
The collisions between the males can be violent enough to kill.
The footage was recorded for the BBC natural history series Life.
"Even though this is one of the most common of the large whales, very little is known about its actual sexual behaviour," says Life producer Dr Ted Oakes.
"One of the most interesting things is that humpbacks have never been seen to mate."
But what has been filmed is the epic battle between males to get mating access to the female whales.
Up to 40 males swim behind a single female at speeds of up to ten knots, each jostling to obtain a dominant position.
"It's the closest we're ever going to get to dinosaurs fighting. It's the largest battle in the animal kingdom and it feels like something out of Jurassic Park," says Dr Oakes.
Cameraman Mr Roger Munns filmed most of the underwater footage of the heat run for the BBC.
Mr Munns had to freedive whilst holding his breath to get shots of the whales swimming past him at speed, as the use of scuba tanks would disturb the humpbacks.
"We had to find the whales when they are on the heat run, which is hard," says Dr Oakes.
"Then we had to position the diving team in front of the charging pack of whales for them to have any chance."
"At one point I think Roger had the female and seven or eight males go past him. He said it was the most incredible experience of his life. Like standing in the middle of a motorway."