A wall at IDEO Chicago that is an interactive system allowing the participant to view the size of the annual Monarch butterfly migration site in Mexico (the number maps to the amount of butterflies on the wall that have their wings open). This roughly maps to the population size of a given year.
Sources:
- Instagram post with video: https://www.instagram.com/p/C8ckPxkP8VK/
- Data from Monarch Watch