If you're a multimillionbillionzillionaire, which is the only way that you could open a good zoo as a private individual then you would probably be buying hundreds or thousands of acres so neighboring property values likely wouldn't matter.
If you are a thousandaire (i.e., a regular person) and are determined to build a zoo then it will probably resemble the Capital of Texas Zoo (see photos in the gallery). In this case you will likely be building your zoo in an area where property values are so low that no one will care.
If a good zoo, aquarium, or theme park opens up and people love it then property values can skyrocket. When Walt Disney opened Disneyland he couldn't afford much acreage in the surrounding area, which subsequently turned out to be worth multiple millions of dollars. Disney World is huge so that the company would be able to avoid that problem and control and profit from the increased property value in the vicinity of their parks. Again, unless you are a multimillionbillionzillionaire or run a huge company that wants to build a zoo (like Disney) then this is not a real world concern.
