I think it depends on where you draw the line for the word "natural". If you include human behaviour, it is natural, but yes, otherwise it is typically known as "artificial selection" in this context.
I would draw the line differently, with artificial selection meaning intentional breeding activities.
Anything that's incidental to changes in the animal's environment, including increased predation or habitat destruction, would still count as natural selection. That includes cases where the predator is a particularly vicious species of great ape.
Anything that's incidental to changes in the animal's environment, including increased predation or habitat destruction, would still count as natural selection. That includes cases where the predator is a particularly vicious species of great ape.