HELP NEEDED - Invasion of the Egrets

Little did I know when I sculpted these bird-women last year that they would come to be  a reflection of things to come; invasion of these disgusting Egrets/Herons was just a season away...
Pardes Hanna, specifically the area known as the Wadi, has been taken over by a huge flock of these messy, nesting, noisy, smelly birds, which have moved into the pine trees just a stone throw from my life. Unfortunately, throwing stones at them endangers the passers by between my terrace and the trees and its a risk I am on the verge of taking!
The local authorities are at a loss as to how to solve this health hazard and environmental affliction, though from my research I know that cutting off the tree tops is a viable solution. Meantime passers by, parked cars me and everyone around the building I am in, are dealing with a mass of messy smelly droppings and I am about to go shopping for an air gun or a chain saw.
 Someone told me that they are a birdwatchers delight, right in the center of town. As photogenic as they might be, they are bringing my blood to boiling point and I am begging

for help to get rid of them. I know, there are helium balloons, ultrasonic sirens, nets, been to that website, read it and heard that these are ineffective.There is evidently no national organization that will deal with it - ANY IDEAS ANYONE????