How Important Are Bird Colonies as Information Centers?

Abstract

Proponents of the Information Center hypothesis suggest that colonially breeding birds learn the location of good feeding sites by following successful birds from a colony, that such information exchange was critical to the evolution of coloniality, and that colonies acting as Information Centers are important for birds in all colonial taxa. The evidence supporting this hypothesis, however, is indirect and could result from behaviors other than information exchange. Further, information exchange may not be as important as other mechanisms whereby birds may more effectively exploit their food resources by nesting colonially. Received 20 March 1981, accepted 31 August 1981. NOTINC that some Quelea (Quelea quelea) followed more purposeful birds from a com- munal roost, Ward (1965) hypothesized that followers had foraged unsuccessfully and that they now followed successful (i.e. the more purposeful) birds from a roost to good feed- ing sites. Subsequently, Ward and Zahavi (1973) expanded this Information Center hy- pothesis to include colonies of breeding birds and considered such information exchangeto be important in the evolution of coloniality. The purpose of this paper is not to disprove the Information Center hypothesis, but to question its supportive evidence and universal importance among colonial birds. Therefore, I first discuss several methods by which birds may locate good feeding sites and then analyze the evidence for intraspecific information ex- change, intra- and intercolony variability in intraspecific information exchange, and inter- specific information exchange. Finally, I ex- amine the possibility that information ex- change was important in the evolution of coloniality, and consider the restricted situa- tions where information exchange could be useful.