Which of the following are examples of active bird control measures?

Active bird control measures are methods that involve direct and intentional actions to deter birds from specific areas. The reasoning behind selecting pyrotechnics and falconry as examples stems from the nature of these techniques, which are proactive and dynamic in their approach to bird control.

Pyrotechnics, such as noise-making devices and alarms, are designed to frighten birds away through sudden, loud sounds that mimic threats in their environment. This method creates a sense of danger in the area, encouraging birds to relocate.

Falconry involves using trained raptors to deter other birds. By introducing a natural predator into the environment, falconry leverages the instinctual fear that prey species have, effectively scaring them away from critical areas.

In contrast, the other options do not embody the same active characteristic. Water sprinklers and fencing serve as passive deterrents, while barriers and warning lights rely on physical and visual deterrence without direct intervention. Habitat modification and chemical repellents, while still effective, also represent more indirect measures that do not actively engage with the birds themselves.