The Congo section of the Bronx Zoo is so full of photo ops. Yesterdays and todays shots were taken there. This guy a mandrill is one of my favorites to photograph there.
It's a difficult situation to shoot in. They have of course thick glass between you and the great apes. It causes 2 problems. Reflections off the glass solved by a polarizer filter and scratches on the glass solved by careful focus with a shallow depth of field.