That's not even the worst of it, either. Viruses evolve faster than birds; allowing the disease to spread unchecked is likely to result in more virulent strains emerging. This could potentially include strains which can infect other species, including humans.
Yeah, that's what I thought as well. Isn't that the reason we need a new flu vaccine every year? Because viruses can mutate and adapt faster than animals can?
I don't know anything about biology so admittedly I'm speaking out of my ass here, but that's certainly what it seemed like to me.
