https://en.wikipedia.org/wiki/Bird_control
Bird Control Methods:
http://www.birdcontrolmethods.com/
Dead birds
The use of model or actual dead birds is used to signal danger to others.
Scarecrow
Bird scarer
A visual bird-scare balloon.
"Terroreyes". Licensed under CC BY 3.0 via Wikipedia - https://en.wikipedia.org/wiki/File:Terroreyes.JPG#/media/File:Terroreyes.JPG
Hawk kite
Propane cannon
"Gas gun bird scarer". Licensed under CC BY-SA 2.0 via Commons - https://commons.wikimedia.org/wiki/File:Gas_gun_bird_scarer.jpg#/media/File:Gas_gun_bird_scarer.jpg
Bird control spike
"Fuglepigger (bird spikes) (ubt)" by 2012 by Tomasz Sienicki [user: tsca, mail: tomasz.sienicki at gmail.com] - Photograph by Tomasz Sienicki (Own work). Licensed under CC BY-SA 3.0 via Commons - https://commons.wikimedia.org/wiki/File:Fuglepigger_(bird_spikes)_(ubt).JPG#/media/File:Fuglepigger_(bird_spikes)_(ubt).JPG