Clip: Episode 2 | 3m 39s
Nature creates her own battles. In the waters around Hawaii, Humpback Whales complete a mass migration from northern feeding grounds; they are gathering to mate. But males outnumber receptive females, and a testosterone-fueled event known as the heat run sees a brawl of gargantuan proportions as the males clash for the right to mate.
Aired: 06/28/17Video has closed captioning.