Final answer:
The part of an animal's home range that is defended against intruders is its territory.
Step-by-step explanation:
The part of an animal's home range that is defended against intruders is its territory. Many animal species, such as birds, fish, reptiles, and mammals, exhibit territorial behavior. They defend their territory to protect their nest, food sources, and offspring.
Territorial behavior can be displayed through various means, including warning displays, vocalizations, and physical aggressions. For example, male gorillas pound on their chests and thump the ground to warn other males to stay away from their area.