Couple porcupine observations from very up close:
1. They are noisy. Spines click in my opinion to ward off predators.
2. They make noises-like porcupine talk sounds like.
3. They can climb trees.
Had a 'pine about the size of a grown beagle walk up on me in Colorado. they make a lot of noise ....I thought it was gonna be a cow. When he realized I was there he started yakking at me and edged off to a tree which he promptly climbed constantly yakking at me.
We were under landowner rules to shoot every 'pine because the sheep were getting injured. I let this one ride.