Money, money, money. Not that many zoos have the financial clout of the Bronx. That spiny desert habitat in the photo holds 2 lemur species, and probably cost hundreds of thousands to create.
But most of the zoos that have old buildings are some of the main zoos in North America (f.e. Lincoln Park zoo's lion house and National Zoo's ape house), so I'm sure they have some money.
You are perfectly correct on the animal species in the photo mstickmanp. I also agree with your point in terms of the ancient animal buildings...either renovate them or bulldoze them!
