"The term "authorship" implies that, for a work to be copyrightable, it must owe its origin to a human being. Materials produced solely by nature, by plants, or by animals are not copyrightable."
So the question remains: is there a copyright at all?
Was the photo really produced "solely" by the animal? No. You couldn't exactly say that a monkey with a camera lives in a natural environment.
The real talent here was preparing the camera for primate use, giving the camera to the monkey, somehow getting it back, and developing the photo. The work absolutely owes its origin to a human being. This is an unambiguous case: the man owns the copyright.
Huh. I'm thinking, the law actually could be pretty specific about who pushed the shutter button. IT wasn't the man.
Laws aren't generally written in some context-agnostic way, like a philosophy class works out after a bull session. Its lawyers writing about what's at issue at the time.
"The term "authorship" implies that, for a work to be copyrightable, it must owe its origin to a human being. Materials produced solely by nature, by plants, or by animals are not copyrightable."