As part of Citizen Science Month 2023, we’re sharing excerpts from ‘Into the Zooniverse’, a series of books celebrating the projects and people of the Zooniverse.

You can find and download all editions of ‘Into the Zooniverse’ here.


SQUIRRELS OFFER A FASCINATING lens into the complex dynamics driving species survival in our dramatically changing landscapes. Only a tiny genetic difference (in the MC1R gene controlling the amount of dark pigment) separates black versus gray squirrels, but that difference has a significant impact on survival. Until 150 years ago, black squirrels were more abundant than gray squirrels across North America. Now, the black squirrel is rare, except in cities.

Through the Squirrel Mapper project, over 140,000 images of squirrels have been uploaded into the iNaturalist platform and thousands of people have contributed over a million classifications of these images on Zooniverse. The team, led by researchers at Hobart and William Smith Colleges and SUNY-ESF, recently published a paper using Squirrel Mapper data from 43 cities in the eastern U.S. and Canada. In the article, they note that cars are the primary driver of mortality for squirrels in cities, and consider whether the black squirrel is easier for drivers to see (and thus avoid) against the gray asphalt of cities. In contrast, gray squirrels have better camouflage from predators in forest and rural settings.

The landscape continues to change rapidly. Will the gray squirrel, and other mammals like it, be able to adapt quickly enough to better survive in urban centers? 

Image credit: SquirrelMapper Project

Summary by: Laura Trouille

Check out this project: here

View the full ‘Into the Zooniverse’ book: here