They ceaselessly change location and can continue their deterrence work over the course of their lifetime, well over ten years. They also cannot scare away larger birds such as geese or cranes, which are far more dangerous to aircraft at impact than smaller species. The cost and complexity of using raptors makes a program difficult to maintain, including the training, licensing, and full-time employment of experienced falconers. A steady supply of trained raptors is rarely available. Falconry is of limited use in bad weather conditions such as fog, heavy rain, or high winds.
Raptors are also unavailable to work while in stages of their yearly molts.
Raptors cannot be recalled once they have begun their flight. They cannot be stopped upon the approach of a plane. Solution Border Collies have been bred to run a hundred miles a day and will work for hours on end. They can work daily for long periods of time and rarely tire. Not only can they deter the largest of birds, particularly Canadian geese, but are also highly effective against larger wildlife like deer and rabbits.