By Susan Milius
Many males of an Australian crayfish species consistently fake their way through macho confrontations, a new analysis of rivalries indicates, even though evolutionary theory says that such bluffing should be rare.
When two male slender crayfish (Cherax dispar) encounter each other, the one waving bigger claws typically sends the smaller-clawed creature fleeing, say Robbie Wilson of the University of Queensland in St. Lucia, Australia, and his colleagues. Yet the researchers’ measurements show that the biggest claws don’t necessarily deliver the strongest pinch.