Animals Defend Their Territory

Territoriality is least likely with insectivorous birds, where the food supply is plentiful but unpredictably distributed. Swifts rarely defend an area larger than the nest.
Conversely, large solitary (or paired) carnivores, such as bears and the bigger raptors require an extensive protected area to guarantee their food supply. This territoriality will only break down when there is a glut food, for example when Grizzly Bears are attracted to migrating salmon.