they weren't shooting the birds in TX they were setting off big booming fire works and if you went outside could see them flash too. They were trying to scare them away from roosting on their buildings but don't think it really works.

The way I remember it explained about the crows wasn't so much they were over populated because they all disperse during the day but they choose to roost together in the man made city sanctuary and make a royal mess. Where as if the city wasn't there they would still do so but in smaller groups. But they are probably some over populated in those areas because of all the trash people make for them to feast on.