I wasn't attacking the park in any way, simply pointing out a fact. I'm not sure I entirely understand the point of your post in reply to mine, but I'll try to answer it:
"Is it really?" -- assuming you mean the year-and-a-half time frame being a long time, then yes it is when you're talking about the reproduction of easily-bred animal species.
"Is it that easy to put together a collection of rare and important breeding animals out of nowhere? " -- no it isn't easy to put together a collection of rare and important breeding animals, but you're not talking about rare and important breeding animals, you're talking about meerkats, wallabies etc - you even made a point of mentioning goats and giant rabbits!
"They seem to spend quite a bit of time waiting for suitable animals to become available, then they don't, taking not-so-hot animals in the hope that prime breeding specimens might come along when they've had them for a while. Completely new enclosures have to be built with money that has to come from somewhere when a species does become available." -- honestly this bit doesn't seem to match the context of your preceding two sentences, which is why I'm confused about the point you were trying to make in your post