INVESTIGATIONS OF THE NATURE OF LAMBS INDIVIDUAL ODOR SIGNATURES

In an attempt to gain further insight into the sources and characteris tics of lambs' olfactory signatures, we observed ewes' responses to fa miliar and alien young whose odours were experimentally manipulated. W hen tested several hours after parturition, ewes accepted their own la mbs that had been anointed with an artificial odorant at birth, but re jected alien lambs bearing either that same familiar scent or a novel odour. Ewes nonetheless appeared capable of discriminating between ali en lambs treated with the familiar versus novel odorants. Alien young anointed with amniotic fluid collected from the ewes' own offspring we re rejected to the same extent as aliens treated with their own (alien ) amniotic fluid. Thus, neither artificial odorants nor amniotic fluid masked the lambs' individual odours, nor did they preclude ewes' lear ning of those phenotypic traits. Ewes may be predisposed to learn a li mited range of biological odours associated with their newborn lamb, a nd such individually recognizable cues appear not to be carried in the amniotic fluid nor acquired postnatally from the mother.