I wonder if, even without finding human cities or remains, you could infer our existence from the fossil record, from the layer where a boatload of plant and animal species went from being localized for millions of years to being all over the place all at once.

And the burnt plastic https://en.wikipedia.org/wiki/Plastiglomerate

Yeah, those hippos could all be killed in a week by a few sharpshooters and a helicopter.