Not exactly a tribe, but there is the case of the Lykovs: https://www.smithsonianmag.com/history/for-40-years-this-russian-family-was-cut-off-from-all-human-con

Not exactly a tribe, but there is the case of the Lykovs: https://www.smithsonianmag.com/history/for-40-years-this-russian-family-was-cut-off-from-all-human-contact-unaware-of-world-war-ii-7354256/ https://www.smithsonianmag.com/history/for-40-years-this-rus... They just figured that the other humans were probably up to some fancy shenanigans again, instead being impressed by things like cellophane (granted, they had the benefit of knowing of the existence of the outside world). I think it might be similar for many isolated tribes. By now they have probably seen enough signs to deduce that the things they're seeing are created by fellow humans, since satellites and planes have been a thing for a few generations now. Especially with satellites having predictable orbits.