I'd say more likely it was caused by a group of rambunctious and unruly
teen birds. The problem is that Mother and Father birds just don't
discipline their baby birds the way they used to. As a result, the baby
bird grows up feeling unloved and unwanted, and at the first
opportunity joins a bird gang to prove it's self worth and to join a
common culture where a form of self-identity can be nurtured.

HTH.