Persistence in Love

On Maud Island, evolutionary biologists from the University of Toronto have been studying the mating habits of giant male Cook Strait weta. Not only do males travel more than twice as far as females but small, long-legged individuals walked further, acquired more mates, and transferred more spermatophores to females. Biologist Clint Kelly said the findings are a rare example of sexual selection favouring traits that promote greater mobility in one sex only. “This is exciting because it suggests that sexual selection for smaller, more mobile males could be responsible for some of the impressive sexual difference in body size in this species,” Kelly said. This phenomenon may also help to explain why males are smaller than females in some other animals. Male weta can walk over 90 m each night in search of a mate – roughly equivalent to a 7000 m outing by a human male.