But, if the birds derive a significant portion of their yearly calories from eating berries during the harvest, you will still do damage to bird populations. Also, an open berry field keeps birds nearby. If the birds can't eat the berries, then what incentive do they have to stick around and eat harmful insects?
I'm not necessarily against the bird-lasers, but it's worth considering their side effects.
I work on a system that strives for 100% efficiency, I think it makes the it extremely fragile. Loss is also tolerance for upset. It might be cheaper to produce more and not implement this system at all. Innovation comes from increase the size of the solution universe over micro optimizations.
I'm not necessarily against the bird-lasers, but it's worth considering their side effects.