those wolves don't cross borders those because they already have what they need, and avoid upsetting their neighbors. not because the other wolf built a fance and has an army that will kill him, and is forced to live in his territory and pay taxes so his territory can be protected ny an army that will kill any wolves that enter without permission.

Nobody denies the existence of boundaries between things in general

I do, I refuse to admit the existence of rivers!

I feel like OP is trying to use science to justify the current militarized borders and state appointed violence against the people who cross them. It's a terrible comparison because natural territory boundaries are nothing like that. No creature in the animal kingdom has crap like I.C.E. and Border Patrol.