Orientation response of newborn rabbits to odours of lactating females: relative effectiveness of surface and milk cues

To assess temporal and spatial variations in the emission of the odour guiding them to the nipples, we exposed newborn rabbits, Oryctolagus cuniculus, to lactating females in a series of simultaneous olfactory choice tests. They showed a clear preference for females in early, rather than late, lactation, and in the prenursing, rather than postnursing, phase. Furthermore, the female's abdominal, and specifically nipple, regions were more attractive to pups than the back and non-nipple abdominal areas. Finally, the surface odour. cues from the abdomen of lactating females were as attractive as the odour of rabbit milk itself. These data suggest that the source of the active compound eliciting preferential orientation is located on the nipple, a site allowing simultaneous evaporation in air and dissolution in milk. (C) 2001 The Association for the Study of Animal Behaviour.