Well Durham Tees Valley has a problem with birds, usually gulls and lapwings. Not sure if they still do but they did employ a falconer to scare off the birds. The falcon use to sit outside the tower on a perch by the taxi way. So it isn't as silly as it sounds and it works a treat. The falcon doesn't have to fly around it just has to sit there to frighten any birds away. Much like people who put plastic herons next to their pond to stop any other herons from approaching the pond.