Avitrol is a pesticide used to poison birds that cause a nuisance, such as pigeons nesting on building structures, or flocks of some bird species in farmers’ fields for example. The goal here is not to actually kill the bird but make it sick enough that it emits distress calls, thus making other birds fly away from it. The chemical triggers various reactions up to convulsions, and if properly applied, the birds are supposed to recover within a certain time frame, but sometimes the bird dies instead.
However, since the outcome of the use of this pesticide relies on the proper training of qualified exterminators, and the proper procedure for dosage, placement, and timing of baits, incidents have happened where bird species not targeted were injured or killed. There is also the concern of ‘off-label’ use, and intentional misuse.
It is also known that even though the pesticide will not directly kill a bird of prey if they eat poisoned birds, it can have an impact on their sense of orientation, which can be fatal due to the high speeds they reach when hunting prey.
This unintended consequence can be a concern when these non-targeted species are already endangered, such as the Peregrine Falcon. These birds of prey have been successfully introduced in many cities with the specific goal of controlling pigeons, one of their favorite preys.
If a pesticide is used to poison their prey, it can be challenging for the peregrine falcon to feed on healthy pigeons in cities where the pesticide is used, and successfully survive in that environment.