The notion that men are more variable than women has become embedded into scientific
thinking. For mental traits like personality, greater male variability has been partly attributed …

We propose a practical concept that distinguishes the particular kind of weaponry that has
evolved to be used in combat between individuals of the same species and sex, which we …

Highlights•Crustaceans produce large but weak claws as dishonest signals of their
strength.•Crayfish did not use large, weak claws as signals during territorial …

Animal weapons are diverse and often exaggerated structures associated with sexual
selection and male–male combat. Despite their diversity, our knowledge of these structures …

Much research on animal communication has addressed how costs such as social costs or
physiological costs favor the accuracy of signals. Previous work has largely considered …

Crustaceans are known for their ability to autotomize and regenerate their appendages. The
appendages that are most often autotomized are their chela, often specialized as claws …

Highlights•We studied traits used to escalate aggression in two species of invasive
crayfish.•Both species escalated and resolved disputes using their claws as signals.•Claw …

In many species, individuals contest resources using specialized morphologies to
overpower rivals, hereafter referred to as weapons. Despite their importance in fights, little is …

A major challenge in the study of animal communication is distinguishing whether signals
convey honest or dishonest information. Biologists infer the honesty of a signal from its …

Multiple causes can determine the disturbance of natural equilibrium in a population of a
species, with a common one being the presence of invasive competitors. Invasives can drive …