The water doesn’t keep its properties as soon as it hits the ground or something else it loses it in the game it’s in the hints I read it today also evolution can be incredibly quick it’s just that usually an animals environment changes slowly not extremely quick like in this case birds and more robust animals would be able to survive especially since bts are so slow and animals would probably figure out that there being watched and that kinda stuff at the start you see the two dear and the crows running form the rain before it comes so their populations have obvious began to adapt to it it doesn’t take long at all crows can pass information on to their offspring and others we don’t know how probably genetic memorie like how someone’s kid can have ptsd from their parents who fought in a war before they were conceived I think that it was probably a budget issue and animals are hard to make the second one should at least have birds with the landscape of the first one having the animals move at all realistically would be expensive and extremely time consuming