The most popular form of zoo photography is the animal portrait. Just as in human portraiture, an animal portrait must go beyond description and instead express the character of the subject. I found a moment when this pygmy chimpanzee, also known as a Bonobo, was seemingly lost in thought, and made a tight black and white facial portrait of it through the heavy plate of glass that lines its enclosure at the zoo. It is a strikingly human expression, underscoring the close biological relationship between primates and man.