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Citizen Science

A Coat of Many Colors

Explore Evolution in Action With Squirrel Mapper Citizen Science

The Science Teacher—January 2020 (Volume 87, Issue 5)

By Jill Nugent

A Coat of Many Colors

Squirrel Mapper is a National Science Foundation (NSF)–funded citizen science project associated with the State University of New York’s College of Environmental Science and Forestry (SUNY-ESF) and the Department of Biology at Hobart and William Smith Colleges. In 2019 the Squirrel Mapper project expanded and is now hosted on the iNaturalist platform with an additional project extension hosted on the Zooniverse platform. Squirrel Mapper invites students to help further what we know about gray squirrel (Sciurus carolinensis) color morphs observed in nature.

The gray squirrel is native to North America and is observed to have two color morphs, gray fur and black fur (See Figure 1). Over the past 200 years, the ratio of observed color morphs appears to have shifted. Historical records indicate that the black color morph was most commonly observed in 19th century North America, while the gray color morph is the most observed color morph in present-day North America. Squirrel Mapper engages the public in exploring scientific questions relating to the changing coloration of gray squirrels. Using Squirrel Mapper, students submit observational data and explore scientific questions related to the adaptation of gray squirrels to various environments, as well as investigate possible influences associated with the observed color change over time.

The gray squirrel is observed to have two color morphs, gray fur and black fur.

Project goal: To further understand gray squirrel coat color morphs and their change over time

Your task: Observe and report observations of gray squirrels

Science discipline: Life Science

Squirrels are fun animals to observe. They are relatively abundant, easy to identify, and active during the day. School campuses and neighborhoods provide a natural setting for squirrel observations. To get started, your gray squirrel observations can be submitted to the iNaturalist Project Page, or if you prefer, they can be submitted to iNaturalist through the SciStarter project platform (See “Helpful Project Links”).

Research-grade iNaturalist observations (observations that are confirmed by two separate reviewers and are associated with locational data) are shared with the Squirrel Mapper Zooniverse Project. In this project, images are classified by coat color and are then mapped to corresponding habitats. The large data set will help contribute to the understanding of gray squirrel adaptation across varying landscapes, making it less of a “gray area.”

Materials you will need:

  • a computer with internet access (or a mobile device)

Examining coat-color distribution across diverse landscapes may reveal patterns and insights into color morph change over time. Changes in the environment such as temperature, decreases in old-growth forests, increases in urbanization, hybridization with other squirrels, and predation pressure are some of the factors contributing to the coat color changes observed. In addition, genetics research continues to yield abundant information regarding coat color in gray squirrels, including the small genetic difference that separates the color morphs.

The gray squirrel is native to North America, but it is an introduced species in the United Kingdom. The introduction of the squirrel into non-native habitats provides another setting to explore color morph distribution across varying landscapes. Educators may be interested in having students explore scientific literature on coat color genetics, as this provides an extension to the Squirrel Mapper project (See “Additional Resources” for an example).

Because squirrels are so engaging to observe, your students may be interested in additional squirrel citizen science projects. Project Squirrel and White Squirrel Mapping are two additional citizen science projects that are also well-suited for classroom implementation (See “Helpful Links”).

The Squirrel Mapper citizen science project provides connections to key themes such as adaptation, genetics, evolution, urbanization, climate change, and more. Students will enjoy studying squirrels, learning about change over time, and contributing to real-world science. In the words of Squirrel Mapper, “Together we can crack this nut!”

Squirrel Mapper at a glance

When: Year-round, anytime.

How: Upload and share your squirrel images and observations on the project’s iNaturalist page (See “Project Home”). You may also submit your iNaturalist observations through the Squirrel Mapper page on SciStarter (See “Project Link on SciStarter”). An additional Squirrel Mapper activity is available on Zooniverse, where you can help classify research-grade squirrel images from the project’s iNaturalist observations (See “Project Extension on Zooniverse”).

Where: Any geographic location where gray squirrels are found

Time needed: Variable, as much or as little time as desired.

Special equipment needed: None

Cost: Free

Contact for more information: For more information, the project administrators can be contacted via the main website. The Project is also on Twitter, @squirellsevolve

Safety: As with any science lab, classroom, or field activity, always ensure that you are following recommended safety practices; for more information on safety in the science classroom visit

Helpful Project Links
Project Information:
Project Home iNaturalist:
Project Extension on Zooniverse:
Project link on SciStarter:

Additional Squirrel Projects on SciStarter:
Project Squirrel:
White Squirrel Mapping:

Additional Resources:
Research article on gray squirrel coat color genetics:

Biology Citizen Science Evolution High School

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