Osmetrichia: specialized scent hair in black-tailed deer

Abstract

Black-tailed deer ( Odocoileus hemionus columbianus ) possess a conspicuous tarsal hair tuft covering the tarsal gland which is located on the inside of the hock. The central hairs of that tuft carry a strong smelling mixture of sebaceous and urinary components. These central hairs are short and stiff in comparison to the outer hair of the tuft and the deer's other body hair. These “scent hairs” have large chambers between the cuticular scales, and the scales have comb-like group of ridges. Lipids, in which volatiles are trapped, are held on the hair by these two features. The term “osmetrichia” is proposed for the specialized scent hair. No comparable features were found on hair covering the metatarsal gland of black-tailed deer, the tarsal gland of white-tailed deer ( O. virginianus borealis ); the subauricular gland of pronghorn ( Antilocapra americana ); on scalp, axillary, and pubic hair of Homo sapiens ; or the ventral gland hair of Mongolian gerbils ( Meriones unguiculatus ). SEM pictures of the trough-like osmetrichia of the Mongolian gerbil are presented.