Interestingly enough I visited 65 zoos on my latest road trip and because there was a large number of small ones I only saw 11 zoos with giraffes. Of those zoos 9 of them had Reticulated Giraffes and 2 had Masai Giraffes (Racine and Timbavati) but Timbavati had zero signs on the exhibit and I have a feeling that the giraffes might be fairly new to the park. A baby was off in its own mini-enclosure and visitors were encouraged to get close and even pet it if they could.
