The Influence of Demonstrator Quality on The Social Transmission of Food Preference in the Norway Rat (Rattus norvegicus)

Abstract

An observer rat that interacts with a conspecific, a demonstrator that has eaten a flavoured food, is subsequently more likely to eat that food than an alternative, novel food (Galef & Wigmore, 1983). In the first part of this thesis, four experiments were undertaken to determine the influence of unreliable demonstrators on observer food preference. In the first three experiments, observers were poisoned after interaction with demonstrators; a demonstrator that demonstrated a food that led to poisoning was considered an unreliable demonstrator. The first experiment compared the influence of an unreliable demonstrator and an unfamiliar demonstrator on observers' food preferences. Experiment 2 compared the influence of demonstration from an unreliable conspecific and a familiar conspecific that had only provided irrelevant information. The third experiment compared the influence of an unreliable and a reliable demonstrator. Experiment 4 compared the influence for protein-deficient observers of a demonstrator that had previously demonstrated a protein-deficient diet and a demonstrator that was unfamiliar. None of the first four experiments showed a significant difference in effectiveness of social transmission due to demonstrator quality. In the second part of the thesis I investigated the influence of familiarity on demonstrator effectiveness. In Experiment 5, the influence of local sisters was compared with that of unfamiliar non-relatives as demonstrators. Sisters were not better demonstrators than unfamiliar non-relatives.