Chapter 4 - Territorial Behaviour and Density Limitation

Abstract

This chapter focuses on the territorial behavior and limitation of population density in birds. Territorial behavior is one of the most obvious manifestations of dominance. It is so ubiquitous a mode of social organization, and in birds such a conspicuous activity, that it hardly needs a description. In its most extreme form, a territory is seen as a defended area of fixed location and exclusive use, with clear boundaries separating it from the territories of neighbors, and proclaimed with distinctive displays and vocalizations. In a less extreme form, territories may overlap between neighbors with a core area defended more vigorously than the rest. In an even less extreme form, the overlap between neighbors is almost complete and defense is barely noticeable. The term “home range” is often used for dispersion systems of this type. But whatever the extent of defense, exclusive use, or overlap, such dispersion systems lead to a fairly even distribution of individuals throughout a suitable habitat. The benefits of territorial behavior for an individual include the assurance of a resource, such as food, mate, or nest site, or some combination of these. The benefits also include any increased protection against predation and disease that spacing out or familiarity with the area confers.