Ok, I'm probably giving this zoo an extra star just because it is the zoo of my childhood.
Though to be honest, they really deserve all 5 stars. First off, it is a free Zoo. That is right, no admission fee, and they still manage to have exhibits and habitats being updated on the regular.
They have several donation boxes around the zoo, so anyone visiting and wanting to support the zoo may make a donation (many state how much it costs to pay for the animals' feed each day). When you total those numbers up, it's actually pretty amazing to me that they have so many animals and can still manage after all these years (I am now 30) to remain free to the public.
They just recently had a new lion cub, and I'm a little sad that I was there a few weeks too early to see it.
One of my favorite things that was not there when I was young was the rainforest birds building. So many beautiful birds, and you are just walking through a huge room full of them, no cages to ruin your photos--just be careful not to hold the doors in and out open and let any of them out. My nieces were just enchanted by getting to be so close to the Macaws.