The males are fiercely territorial, only allowing females to enter their range.

The Plainfolk were fiercely territorial but they were not empire-builders.

Cohen suspected tyrannosaurs might be fiercely territorial, since each animal would require huge amounts of meat.

Shrews are fiercely territorial, driving off rivals, and only coming together to mate.

White damsel fish have their own allotments on the sandy floor and are fiercely territorial.

The breeding male is fiercely territorial, each defending its turf against invasion by other males.

Peregrines are fiercely territorial and protective of their chicks.

Black carpenter ants are fiercely territorial with regard to other ants.

D. leucomelas frogs are diurnal by nature, and are known to be fiercely territorial.

Jacky makes note of a fiercely territorial banty rooster that she may have use for someday.