I think this logo is very well designed. The subject, a wild cat and leaves, is very appropriate for a zoo. Also, the logo looks professional enough to attract adults, but since it uses the image of an animal, it will also appeal to children. The concept of the cat peering through the leaves gives a sense of discovery, which is what a zoo is all about. Overall, I think this is a great design.
Specifically referring to color, the muted earth tones really call to mind the natural world associated with a zoo.