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Frequently Asked Questions

Why Squirrels?

Squirrels are useful organisms to study because they are active during the day and everyone has an opinion about them. Additionally, squirrels can be important indicators of local ecology because they are resident in small territories and active year round, they require a range of resources that are also important to many other urban animals, and their populations rise and fall with the same predators and environmental conditions that affect our neighborhood wildlife.

What do I need to know about squirrels to be a Squirrel Monitor?

You need to be able to tell the difference between fox and gray squirrels, whether or not they are present in your neighborhood, how many there are, the full zipcode of the observation site, and a little more basic information about the observation site. Take a look at the data sheet and you'll see how easy it is.

How do I tell the difference between Fox and Gray Squirrels?

Fox squirrels have a rusty belly and a black outline to their tail throughout most of the country. Gray Squirrels typically have a white belly and the tail looks frosted in white. In many places you may see Gray squirrels that are all black and in a few places you may see a white one. Grey squirrel adults are also smaller than Fox squirrels.

So you're saying Black Squirrels are Gray Squirrels?

Sciurus carolinensis is commonly known as the grey squirrel but, just like people, they can have different hair colors. Some are black, some are white, sometimes they even have a bit of rusty coloration. See the chart below for answers about Red Squirrels.

What if there are no squirrels in my neighborhood?

Absence of squirrels is also a data point. Please report a lack of squirrels. This is especially interesting if the surrounding communities have squirrels.

How often should I observe?

You can observe as many sites as often as you like. It's important to observe a given site at least four times per year (once a season) because the populations are likely to change around these times but many people like to observe a couple of times a week because it's fun and they get an even better picture of what's going on with the neighborhood ecology.  The more observations in the more places, the better.

How long does observation take?

Observation just takes a few moments--if you see squirrels, note the species, location, and other info on the datasheet--that's it.  Often I check the street as I leave for work, look around the building when I get to the office, and walk through the park at lunch.  This way I get three observations a day at three different observation sites. 

What is an observation site?

Essentially, a site is any place you make an observation. Squirrels have relatively small home ranges so the squirrels at one end of your block may be part of a different group than the squirrels at the other end of the block. If you make observations at both ends of the block, you have two sites. For this reason we would like you to report squirrel sightings according to the full ZIP code, i.e. 60614-2874

I would like to volunteer for Project Squirrel.

Great! Thank you. One of the challenges the Project faces is that in some places, monitors are widely scattered throughout the town. If we can increase the coverage of the town, all of the observations become more useful. The way to do this is to make systematic observations along a transect.

Pick a street and walk or ride a bike down the street, stopping to record data at set intervals. If you are working in an area with streets laid out in a grid, just make notes at every intersection. The average suburban block is about the size of one or two squirrel group's territories. Once you've picked your route, figure out the full ZIP code (i.e. 60614-2874) of your observation stops and note this on your observation form before you go out. This is the only information that you can't get just by looking around your observation stop. Use the Postal Service web site to figure out the zip codes.

Walk your transect once or twice, then make a new transect a few streets over and repeat the process. Walk each transect at least once a season (four times a year) to capture data on population fluctuations

If you really get into collecting data and would like to use excel to record your data, email me for the proper formats.

I would like to use the project for school service hours.

Great. Read the section about volunteering for the Project. If this sounds like fun to you and is acceptable to your service coordinator send me an email and cc your coordinator to let me know that you'll be submitting data from a transect, describe the transect, and list the ZIP codes it encompasses. I'll send you some electronic data forms to submit periodically. Once you've completed the amount of work that your service coordinator requires and I validate your data, I'll send a note to your school verifying your contribution.

What about Red Squirrels?

Common names can be confusing. In the Chicago region as well as most cities in the eastern half of the United States the squirrels you are most likely to see are gray squirrels ( Sciurus carolinensis ), and fox squirrels ( Sciurus niger ). Project Squirrel is currently only tracking these two species. However, some people call fox squirrels “red” squirrels. The problem is that there are two other species of tree squirrel that are also called “red squirrel” in the United states and one more “red” squirrel species that is found throughout Europe. The chart below summarizes the names and characteristics.

Common name (as used by the American Society of Mammalogists)

Other common names

Scientific name

Relative size of adults

Distinguishing Coloration


Behavioral notes

Fox Squirrel

Red Squirrel, Field Squirrel

Sciurus niger

Largest tree squirrel in the US

Most populations are a grizzled orange-tan with a rusty belly and black edged tail. Coloration may be different in some parts of the US.

East coast nearly to the Rocky Mountains, from the southern US to southern Canada, also introduced to California and other states

Calm, may tease dogs and cats, scatter nuts throughout their home range.

Pine Squirrel

(Eastern) Red Squirrel

Tamiasciurus hudsonicus

Very small

A crisp, chestnut red with white belly. During summer has a black “racing stripe” on the side

Evergreen and mixed forests throughout the eastern and northern US and southern Canada

Hyper, noisy, make big piles of pinecone scales.

Douglas' Squirrel

(Western) Red Squirrel, Chickaree

Tamiasciurus douglasi

Very small

Much like the pine squirrel but with an olive green cast to the red and a creamy yellowness to the belly

North western US and southern Canada

Hyper, noisy, make big piles of pinecone scales.

European Red Squirrel

(Common) Red Squirrel, Many names in European languages

Sciurus vulgaris


A clean, deep chestnut red with white belly and long ear tufts. Some variation throughout its range

Across northern Europe to Asia and Siberia

Hoards nuts and fungus in hollow trees and in the ground

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