Having spent his entire life in the forest, Hope knows what belongs there and what does not. Grass, dead leaves and twigs crunching underneath feet? Probably one of his fellows, or someone else, walking about close to his territory. Not uncommon at all, so no cause for concern.

A flash of light followed by a strange clicking noise however, that is new.

That is unnatural.

That means there's someone within his forest, someone new.

Hope propels himself from tree to tree, searching for whoever is unfamiliar to him in this forest and discern if they're friendly or dangerous to his home. He is tengu after all-- this is his sanctuary to guard. And when he spies a figure he does not recognize, he announces himself with a mighty flap of feathers and drops heavily onto the ground, opting to intimidate.