Which of the following is NOT an example of passive bird control?

• A. Grass height management
• B. Gas Cannons
• C. Fencing
• D. Managing drainage

Answer: (B)

Understanding passive versus active bird control is key. Passive methods change the environment so birds are less likely to stay or feed there, without ongoing disturbance. Grass height management reduces cover for roosting or perching, making the area less attractive. Fencing physically blocks access, cutting off entry to the area. Managing drainage eliminates standing water or damp habitats that birds may loaf around or nest near. These are all habitat-based, long-lasting adjustments that don't rely on continual deterrence.

Gas cannons, in contrast, are active deterrents. They emit loud blasts to scare birds away and require operation and timing. They don’t alter the habitat itself, but instead provoke an immediate, repeated response from birds. That’s why gas cannons are not considered passive methods.