i agree...i think the monkey could be sharper, but it looks like your focal point got stuck on the tree.
the background is also very blown out. do you have a flash? maybe meter for the sky, and then fill subject with flash? im still new at lighting, so im sure someone more knowledgable will chime to confirm or correct my advice.
cool monkey though!
i can't be sure, but i'm thinking he was probably using a telephoto lens to take this, so flash is pretty much useless here. unless he was setting up the shot? he could have some off-cameras but i don't think that's the case