why do birds fight
Birds get angry and fight for reasons other than simply protecting their nests. Sometimes birds fight to protect a general territory rather than a specific nest. When food is scarce, birds become more territorial and won't hesitate to fight other birds that threaten their food supply.
Birds also occasionally fight to prove their dominance over other birds or to win the affection of a potential mate. Male house sparrows, for example, have a reputation for fighting for dominance. Within flocks of house sparrows, there's a definite pecking order. Male house sparrows have black âbibs on their chests.