Communication of Information Concerning Distant Diets in a Social, Central-Place Foraging Species: Rattus norvegicus1
Bennett G. Galef Jr. McMaster University Hamilton, Ontario
In environments characterized by an unpredictable and patchy distribution of foods, social birds or mammals that forage from a central site (e.g., a burrow, roost, or nesting site) can benefit from exchange of information with conspecifics about the availability and distribution of foods ( Bertram, 1978; DeGroot, 1980; Erwin, 1977; Waltz, 1982; Ward & Zahavi, 1973). Relatively unsuccessful foragers able to extract relevant information from their more successful fellows could learn both the identity of foods successful foragers are exploiting and the locations of those foods. Such socially-acquired information could enhance the foraging efficiency of relatively unsuccessful individuals.
Wild Norway rats are social, central-place foragers; in natural circumstances, each rat lives as a member of a colony inhabiting a fixed system of burrows; when foraging, colony members disperse from their burrow, feed, and then return to it ( Calhoun, 1962; Telle, 1966). Thus, Norway rats are an ecologically appropriate choice for laboratory experiments examining ways in which social interaction might facilitate food acquisition in a social, central-place foraging species.____________________