Reduction of aggressiveness toward familiar neighbors, when compared to aggressiveness toward unfamiliar strangers, can decrease the costs of territory defense. This phenomenon is known as the “dear enemy effect”. Individuals ...

Food access, territory or reproductive partner can generate conflicts between individuals in many species with occurrence of aggressive behaviors. However some species respond less aggressively to intrusion by neighbors ...

Territorial animals tend to respond more strongly to strangers than to territorial neighbors. They may learn the signals of each neighbor, which is defined as neighbor-stranger discrimination or "dear enemy" effect. The ...

Many territorial animals show differential responses against intruders based on the level of threat that they pose. The dear-enemy and the nasty-neighbor effects appear when territorial aggressions are more robust against ...