Two Hypotheses Supporting the Social Function of Odorous Secretions of Some Old World Rodents

Abstract

The functions of odorous secretions produced by mammals are largely unknown though their involvement in social signalling is often regarded as a foregone conclusion. In only a few instances have their effects on reproduction, territoriality and social life been unequivocally demonstrated; in even fewer have their chemical compositions been investigated (Mykytowycz 1972; Ralls 1971; Stoddart 1976). As far as the rodents are concerned most research into the role of odorous secretions has been directed towards Mus musculus L.with Rattus norvegicus (Berkenhout), Peromyscus maniculatus (Wagner), Mesocricetus auratus (Waterhouse) and Meriones maniculatus (Milne-Edwards) receiving less, but still significant attention (Beach and Jaynes 1956; Bowers and Alexander 1967; Bronson 1971; Lisk, Zeiss and Ciaccio 1972 and Thiessen 1968). Almost all studies have been carried out under laboratory conditions. Most rodent species have escaped attention possibly because laboratory stocks are not available. Yet it is from naturally structured and freeliving populations that fundamental observations can be made on secretion complexity and quality in relation to sex, sexual condition, age, season of the year, etc., from which reasoned interpretation of the influences of such factors are possible. Observations of this nature are free from the constraints imposed by laboratory conditions. This study was conducted on seven species in three genera of Old World rodents to examine two hypotheses of fundamental importance to the formulation of future controlled condition experimental investigations.