The census in Central Park clearly benefits from the team’s prior experience. Applying statistics, mapping tools, and common wildlife research methods, they divided the entirety of the park into hectares. The 100 meter by 100 meter plots, O’Connor says, are roughly the range of an individual squirrel. Each plot is set to be surveyed twice, once in the morning and again in the evening, to give some semblance of the day’s true ebb and flow. Each volunteer heads out with elaborate tally sheets, where they describe each of the squirrels they see. Age (adult or juvenile) and primary and secondary colors (cinnamon, white, gray, black) must be recorded. Just as important is the squirrel’s behavior under observation: do they run toward or away from you, or are they totally unbothered? Are they on the ground, foraging, or in the tree chasing something—or being chased?