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MALE killer whales whistle to each other when they’re feeling playful,
according to Frank Thomsen of the University of Hamburg and John Ford at the
Marine Science Center in Vancouver. They recorded sounds from groups of male
killer whales off Vancouver Island. “You often get males from different families
playing in all-male groups for hours,” says Thomsen. “They do things like chase
each other, roll over each other and swim nose to nose.” The scientists heard
the frolicking males make complex, high-pitched whistling sounds, different from
the lower-pitched calls that other whales and dolphins use for long-distance
communication (The Journal of the Acoustical Society of America, vol
109, p 1240). “The whistling seems to be essential to help the males bond,” says
Thomsen.