That may work and there is a solution to crows getting into the garden.

Sing a song of sixpence pocket full of rye, four and twenty blackbirds baked in a pie.

Seriously, bird fertilizer can be just as useful as any other critters releasement can be used, I've heard of several backwoods people using what they call "humanure" to fertilize their soils and they haven't had any difficulties at all. At least that's what they've claimed.
Anyway, use the droppings and compost it all, along with all of your other vegetative matter, and you have some excellent soil treatment!
Plus the shooting practice along with food gathering getting blackbirds to bake into a pie!

That thought crossed my mind. I have visions of the sky turning black with birds like what happened in Kentucky a few years ago. Also, certain bird droppings like pidgeon will make your cucumbers and tomato's taste funny. People who raise homing pidgeons have easy access to prodigeous piles of pidgeon poop so it is convenient to use it as a fertilizer.

I'm not so sure I agree with this but a local rancher attracts crows and ravens to parts of his property where he grows things by depositing 'crow-pickins', bread etc. He says that the bird - rhymes with goop - fertilizes the ground for free. What bothers me about the concept is that birds are communal and have a communal language. When things begin growing I would think they communicate with their friends that there are plenty of free things for them to eat.