大象传媒

Killer whales have learned that grey whales follow traditional migration routes along the North American coast. Falling silent, the killer whales hone in on their target with ease, as the female and young calf must travel slowly. The killer whales push the mother to keep her young calf on the move. It will only be safe if she can stay by its side, for a calf alone cannot defend itself. All too soon the calf will tire and it is then that the killer whales will seize the advantage, separating the calf from its mother. (Courtesy of WHOI)