A lot of threads talk about what the best zoos are, but seem to ignore the many good under 20 acre zoos. What good zoos do you know under 20 acres. I have been to four very good collections- Central Park Zoo- 6 acres Zoo America- 10 acres Buttonwood Park Zoo-10 acres Capron Park Zoo- 8 acres
The Roger Williams Park Zoo in Rhode Island and the Santa Barbara Zoo are a bit bigger, but they are real connoisseur's pieces, well worth a visit if you're in the area. The Santa Ana Zoo is about twenty acres and seems to have markedly improved since I was there.
Perhaps the best 'small' zoo in Australia is Adelaide Zoo. A quick Google search gives its area as 20 acres (8 hectares), so it's right on the cusp of what you'd define as small. It's a perfect combination of interesting species, mostly good-to-fantastic exhibits, beautiful landscaping and location, and fascinating historic elements to appeal to zoo enthusiasts and the general public alike. I was also going to suggest Antwerp Zoo but at 26 acres, it's a little too big to fit the criteria.
Possibly one of the most important small zoos in the world (if not the most) is Bioparc Fuengirola (Spain), of only two hectares
I think the UK is full of great "small" collections - but the definition of a "small" zoo in the UK, is probably different to what someone in the states, or even mainland Europe would refer to as a small zoo. Some personal favourites include Shaldon Wildlife Trust, Lakeland Wildlife Oasis, Amazon World Zoo Park ... And many that I havent been to myself.
Shaldon Wildlife Trust and Ventura Wildlife Park, are both favourites of mine, both very small in size.
My home zoo, Seneca Park Zoo, is only 20 acres in size, and contains a lot of the charismatic zoo animals you’d expect to see.
The Birmingham Wildlife Conservation Park is one that is quite small but still houses a good variety of species with solid exhibits all around. Other great small ones include Servion Buttonwood Park Stone Zoo Valencia Bioparc
The Staten Island Zoo is very small. It has some old sections, but it’s modern areas are very nice and the place is famous for its comprehensive rattlesnake collection.
Erie Zoo- 15 acres- isn't exactly the best zoo, but it has its strength and seems to be getting better
ZooWorld in Panama City, Florida. It’s probably the smallest on this list at 5 acres, and has vastly improved since my first visit in 2014.
Lincoln Children's Zoo, St. Augustine Alligator Farm, National Aviary, and Tracy Aviary are my favorites under 10 acres.
I really like the exhibits and overall atmosphere of the WCS zoos. So for small zoos, I would recommend three of their four establishments: Queens, Prospect Park, and Central Park.