I don't understand why this is a problem.
The roof is surely occupied by birds, rats, and mice.
Is the roof designed to include the natural world or not?
Another possible interpretation is that the grounds are laid out such that rainfall doesn't cause the roof's soil to erode and wash off.
(This is without any positive or negative value judgement, just an observation that we don't have to reach for "it needs to look pretty" to explain why having foxes on the roof isn't ideal.)
I didn’t mean to cast aspersions on this project in particular, just to note that while we often expect nature to conform to our specifications, it may have other ideas…
Obviously the landscaping was designed to look pretty and win awards, not to host actual wildlife