A new model system for studying behavioural traditions in animals

Laboratory paradigms currently available for study of behavioural traditions in animal populations do not provide sufficient information to permit extrapolation from laboratory findings to more natural situations. By focusing solely on the transmission process, such paradigms fail to provide an opportunity to explore fully the complex determinants of the longevity of behavioural traditions and the probability of diffusion of socially transmitted behaviour patterns through populations. The relability of a new model system is established that will permit exploration of the effects of (1) individual learning about the environment and (2) social relationships between bearers of tradition and recruits to a population, on maintenance and propagation of traditions of food preference in colonies of norway rats. ‘Founder’ colonies of four rats were taught an arbitrary food preference. Individual members of the founder colonies were then slowly replaced with naive subject. There generations of replacements after the last founder had been removed from a colony, the arbitrary food preference taught to a colony's founders was still evident. The behavioural mechanism supporting the observed traditional behaviour in rats was identified, as was a possibly important, previously unidentified parameter (the duration of opportunities to learn by sampling alternatives) influencing the stability of behavioural traditions in animals