Monkey Business: Can A Monkey License Its Copyrights To A News Agency?

A year and a half ago, we wrote about a movie that was entirely filmed by chimpanzees, and wondered about who held the copyright on it. Technically, in most cases, whoever makes the actual work gets the copyright. That is, if you hand your camera to a stranger to take your photo, technically that stranger holds the copyright on the photo, though no one ever enforces this. There were some different theories made in the comments about who actually holds the copyrights, but no clear agreement. Of course, the whole discussion was purely theoretical, because it wasn't like anyone was concerned about the copyright.

However, now we have a similar, but different, story where I think it's a very valid question. Mr. LemurBoy points us to a story involving an award winning nature photographer, David Slater, who was in Indonesia in a national park. At some point, he left the camera unattended, and apparently a macaque monkey wandered over and took this hilarious self-portrait:
Now that's the best photo of the bunch, and appears to have no copyright notice on it (though that doesn't mean it's not covered by copyright), but two of the other photos, which the article also claims were taken by the monkeys, do have copyright notices, with the claim being that the copyright is held by the Caters News Agency.

So here's the legal question: how did the copyright get assigned to Caters? I can't see how there's been a legal transfer. The monkeys were unlikely to have sold or licensed the work. I'm assuming that it's likely that the photographer, Slater, probably submitted the photos to the agency, and from a common sense view of things, that would make perfect sense. But from a letter-of-the-law view of things, Slater almost certainly does not hold the copyrights on those images, and has no legal right to then sell, license or assign them to Caters.