The significance of pheromones in olfactory communication in mammals, and the possibility of using synthetic pheromones to influence the behaviour of problem animals, are briefly discussed. The isolation, identification and synthesis of the principal volatile component contained in the pedal gland exudate of the bontebok, Damaliscus dorcas dorcas, viz. (Z)-5-undecen-2-one, are reported. Some of the other major constituents of the secretion have been identified as 2-heptanone, 2 -nonanone, 2 -undecanone and 2,5-undecanedione.