Not at all. You just have to learn when to go, though. Most people don't like getting up early, for example, so if you go right when the doors open, there are hardly any crowds. Also, don't go on a holiday or "significant" day. Mothers' Day here, for example, is not a holiday, per se, but is a significant day when zoos are frequently overly-busy. Usually the zoo staff will tell you what their least-busy times are if you call.
Where is MacGruder?