IF the primitive aliens were anything like us, you could point something like FIRMS at the planet and wait a few weeks. One of the first things I would qualify

IF the primitive aliens were anything like us, you could point something like FIRMS at the planet and wait a few weeks. One of the first things I would qualify as an anthropogenic (xenogenic??) signature, visible from space, would have been regularly setting semi-controlled brush fires to make hunting and foraging easier. Nice bonus it gives you some idea of tribal migration patterns! ed. - but it requires high-res direct imaging of the planet