This may be more of a question, but if it's not going to be in the game then a wish list item!
If it's not a thing, I would LOVE if visitors had a favorite animal like they did in Zoo Tycoon. If the zoo has the favorite animal they would take more pics of it than anything else and their happiness would increase as well as the length of time they stay at the park. They would be able to buy merchandise with their favorite animal on it as well.
If the park doesn't have their favorite animal they will not be 100% happy and not stay at the park as long.
If it's not a thing, I would LOVE if visitors had a favorite animal like they did in Zoo Tycoon. If the zoo has the favorite animal they would take more pics of it than anything else and their happiness would increase as well as the length of time they stay at the park. They would be able to buy merchandise with their favorite animal on it as well.
If the park doesn't have their favorite animal they will not be 100% happy and not stay at the park as long.