A factor that contributed to their extinction was the unfortunate flocking behavior that led them to return immediately to a location where some of the birds had just been killed. This led to even more being shot by hunters as they gathered about the wounded and dead members of the flock.
Among the key changes brought by the Hart-Celler Act: Quotas based on nation of origin were abolished. For the first time since the National Origins Quota system went into effect in 1921, the national origin was no longer a barrier to immigration.
