Fighting and the mechanical design of horns and antlers

Horn-like organs have evolved independently in five extant families of mammals (Alvarez, 1992; Geist, 1966; Goss, 1983; Kitchener, 1991; Savage and Long, 1986). A variety of functions have been proposed for horn-like organs, but behavioural observations in recent years have confirmed their use mostly in defence against predators and intraspecific fighting between males to gain access to females in oestrus (Clutton-Brock, 1982; Clutton-Brock et al., 1979; Geist, 1966; Kitchener, 1991). Horns and antlers are most likely to experience the greatest forces during intraspecific fighting, when they often clash directly against each other. Therefore, in this paper I will review the interrelationship between intraspecific fighting and the mechanical design of the horns of bovids and the antlers of cervids, for which published data are available.