Animal Kingdom is also lacking in pin locations
In Orlando, each Disney World park has pin trading but you are not likely to find great locations at Animal Kingdom. Animal Kingdom is by far the lesser of the four parks when it comes to pin trading. On my last trip, I didn't even bother to look because when I do find them, there usually isn't much to choose from.
Most of the pin trading at Animal Kingdom will be found at concession carts outside of rides. For example, across from the entrance to Everest rollercoaster, a cart has a pin board. There are a few others as well but if the cart cast members lay the board down, you will have to ask.
This isn't a perfect set up because you have to wait for other guests to finish their transactions before you can ask to see the board and that can irritate a hot and frustrated guest behind you that simply wants an ice cold drink. I suggest looking over the cart before getting in line or simply asking a cast member while they pour a beer or fill a popcorn bucket. A simple excuse me could do the trick.
In addition to the carts, you can find pin boards in the two main gift shops to the left and right as you approach the courtyard with the Tree of Life directly in front of you. You might have to ask a cast member where the board is located.