how a flock of birds sucked into the engines of a usairways flight, forced sully sullenberger to ditch the plane in the hudson river. >> few people probably know about a program allowing programs to shoot birds like these out of the sky. to keep the birds from interfering from aircraft. it's a last resort measure, a privilege that's being granted to a growing number of california airports. when it comes to bird strikes, sacramento international airport has one of the highest counts in the nation. >> we have a lot of birds here, and the majority of them we do scare away. >> wildlife biologist julie carr says shooting is always the last option here. >> we try to make this area as unpleasant as possible, using horns, pyrotechnics, basically just to scare them away. when we do have to, it is a last resort. >> reporter: carr is one of four wildlife biologists here in san francisco trying to scare off the birds. >> you need to determine is it an imminent threat. you're aware of where aircraft are, are there any waiting to take off. >> reporter: despite the high number of strikes, carr says t