The 4 types of bird control devices:

• Full Barriers: Netting & Mesh

• Electrical Barriers: Spring Tension Wires and Tracks

• Perch Modification: Spikes, Wires, and Slippery Angled Ledges

• Scare Devices: Sound Machines, Motion Devices, Fogs, and Sprays
  

Only full barriers and electric barriers have a high probability of success longer term.  This is because birds adapt to any system that does not totally block them out or deter them with electricity. Slippery sloped ledges work well in some situations, yet application is very limited.   Sound machines and motion devices have a very low probability of success.  If you are looking for proactive long term bird control read on about what systems both work long term and last the longest.gest.