Overview
- The Biology Letters paper calculated a 98.67% likelihood that the imprint came from a squirrel, with classifications split between eastern gray (50.67%) and fox squirrel (48.00%).
- Because the slab had been removed, the team measured more than two dozen publicly available photos using coins for scale and compared anatomical landmarks to museum specimens of eight local rodent species.
- The authors say the absence of a bushy tail outline does not undermine a squirrel identification because hair rarely leaves clear impressions in concrete.
- Given daytime pouring of concrete, the lack of tracks, and accounts of a nearby former tree, the study posits a squirrel likely fell onto wet concrete rather than a rat being dropped.
- The slab is preserved at the Chicago City Hall-County Building, the authors propose renaming it the “Windy City Sidewalk Squirrel,” and they are developing outreach materials that underscore the limits of trace-based identification.