ABSTRACT
The word “colony” has several different definitions. Its use with respect to seabirds should not be confused with the meaning when applied to human society, where, from Roman times, it has indicated a group of people under the jurisdiction of a country some distance away. In a zoological sense, “colony” describes a group of individual organisms that live close together. It also carries an implication of communication and collaboration, resulting in positive (beneficial) interactions between individuals. In ornithology, the term is usually restricted to a group of individuals at a breeding site, while “flock” is applied to birds which are gregarious at other times of the year or when away from the breeding site. Several authors have considered practical definitions of a colony (Buckley and Buckley 1979, Kushlan 1986, Kharitonov and Siegel-Causey 1988), but others have not readily accepted these definitions, mainly because they do not apply to all species or they include implications that have not been fully researched. In mathematical terms, the individuals in
a colony are clumped or aggregated in space, with other apparently suitable areas remaining unoccupied more frequently than would be expected by chance. One of several methods of demonstrating this is to show that, on average, the nearest neighbor to each pair or nest is significantly closer than would be expected by chance. In sessile organisms such as corals and sponges, the colony is a permanent group, persisting for the lifetime of the individuals and often for longer. The characteristic of permanence is also applicable to many seabird colonies, but in this case it is because of the breeding-site tenacity of many adult birds, the stability of the nesting area, e.g., cliffs and islands, and also because successive generations are attracted to the same colony sites.
