Gasoline.

[Boreas]

A few years ago there was a guy in the neighborhood who was making a little extra money by letting homeless people camp in his yard, selling drugs and raising ringneck doves for game ranches. When he inevitably got busted and then evicted he released his doves into the neighborhood.

The local hawks must have thought they'd died and gone to heaven and set about trying to chow down on the naive newly liberated doves. Well, the doves had other ideas. They turned out not to be such easy pickings and, any time a hawk cruised their nest sited, the doves would mob them furiously and raucously and drive them off. They were frequently joined by the mocking birds and jays in the neighborhood.

We still have plenty of ringnecks here, not so many hawks.

John