Final answer:
Territorial behavior, which includes advertisement, threat, and combat, is indeed true. Display behaviors are commonly used by animals like gorillas and robins to avoid actual fighting, which is safer and more energy-efficient.
Step-by-step explanation:
It is true that territorial behavior includes forms of advertisement, threat, and combat. Animals are territorial and often defend their areas through various behaviors. Those behaviors include advertising their presence, threatening potential rivals, and, if necessary, engaging in combat. However, display behavior that avoids actual combat is more common as it tells other animals to stay away while being safer and using less energy. Examples of this include male gorillas that defend their territories by pounding on their chests and robins showing their red breast to deter others.