[Mustang poop just twenty feet from the car port this morning. The mustangs were in my 'backyard' last night.]
So, we don't observe the brumbies as such; but your point is a valid one:
remember that we pretended to be emus on the old Oudman place? and we thought about what areas we know, and what areas we didn't, and where we might go?
Well, surely the brumbies use the same equation. They surely have memories of food sources and permanent water. And they surely make decisions about moving across their territory on that basis.
there are at least 8-10 emus here now. Limpy Chick and Offsider are defending their turf. Dad and the four cheeky chicks are just outside the house, enjoying some wheat I threw down.
But there is a female with a big boom just behind the fig tree. Offsider has been down independently -- unusual for a male to 'operate' on his own -- to drive them off; but I can here them now as I type.
This went on for fully a half an hour. The chicks have figured out that LC and Offsider just couldn't be bothered to chase them far, and there was enough wheat for everyone.