You're going to get three kinds of answers to this, based on the standard gamist/simulationist/narrativist player-opinions.
Gamist: If it's book legal he should get whatever he wants, just have it appear, explanations are not necessary, he wants an ape he gets an ape. His build depends on it!
Narrativist: Well, he sees having an ape as part of his story arc, so yes, you should find a way to allow him to get an ape. Perhaps with a story hook attached!
Simulationist: Tough nougat, if there's no apes around he gets whatever's around. If he's hellbent on it he should jump on a ship to the tropics. Reality uber alles!
Which you should do is about you and your group's personal values. How do you all approach the game?
I tend to run as simulationist with a side of narrativist. So what I'd do is to say "Well, no ape is just going to magically teleport in. You could pick a local animal. But you know, maybe there's non-wild apes that are close... You could go liberate a sad captive ape from the nobles' zoo in ..." And then if he and the group want to go through a little work, run an Animal Liberation Army session where he might get another ape.
That's not "the right" answer, it's the right answer for me based on my game's values. You'll need to go through the same thought process.