Olfactory Guidance of Nipple-Search Behaviour in Newborn Rabbits

Abstract

As rabbits live in burrows and are most active above ground at dawn and dusk when lighting conditions are poor, they are very dependent on their sense of smell in processing the world around them. The ability to communicate with other rabbits, for example, is largely based on the transmission of subtle olfactory cues. Rabbits rely on odours contained in secretions from specialized skin glands and in the urine and feces for such important tasks as territorial marking and identifying the age, rank and sexual status of individuals (Goodrich and Mykytowycz 1972; Mykytowycz 1965, 1972; Schalken 1976; Bell 1980; Hesterman and Mykytowycz 1982a, b; Hesterman et al. 1984). Given their well-developed olfactory system and established position as laboratory animals, rabbits would therefore seem to be good subjects for developmental studies of olfaction. Not only are they notoriously easy to breed and grow rapidly but, as will be argued here, the newborn pups possess a number of behavioural specializations which make them particularly suitable for such investigations. Chief of these is their total dependence on olfactory cues to locate the mother’s nipples and to suckle (Schley 1977, 1981; Hudson and Distel 1983). The reason for this, and the research opportunities it provides, can be best understood in the context of the rabbit’s unusual maternal behaviour and the demands this places on the young.