He owns the rights to the pictures he takes. No purchase necessary. Especially in the context of wildlife, there are no human subjects to cloud the issue.
My guess was the same as the parent poster's -- the pictures of the monkey grabbing the phone, from the phone's point of view, belonged to the tourist, right? Because the phone belonged to the tourist? The photographer must have acquired those rights afterwards. (Although I don't recall the outcome of the copyright case of the monkey that took its own photograph back in 2014...)
And for me, part of a long list of reasons I will never be in favor of copyright (unless turned back on itself, as the GPL or other free licenses allow).
That concerned pictures taken by the monkey. This is pictures taken by a photographer, with his own camera, by his own will. Nothing remotely disputable.
There'd be no question of rights for any of the shots I saw in the article. My personal property being in your photo, taken in and of a public place, doesn't give me any ownership; if you take a picture of me then it can be more complicated, but an object (or a monkey!) has no likeness rights of which I'm aware.
The ownership/copyright to a picture always belongs to the creative person responsible for creating it, that usually is the photographer. Even if the photo shows persons, the photo is owned by the photographer. Depending on the circumstances of where and how the picture was taken, the depicted persons have to to agree to any publication of the photo - that is what model releases are for.
These aren't selfies, so the relevance is limited, even assuming (imo charitably) that the arguments against copyright in that case are other than specious.
I don't think the "lens inspection" picture was taken on an iPhone, not least of which the stolen/drowned one — partly due to its quality, partly due to its name, and partly due to the positioning of the monkey's hands.
