in the City

bench Tree Tree Tree Tree Tree Tree Tree squirrel

How many squirrels live in Central Park?


But how did we know that?

What is the Squirrel Census?

The Squirrel Census took place in October 2018, when 323 volunteers collected data on all the squirrels in Central Park. To organize the project, the census team divided Central Park into 350 hectares. Each census taker roamed a single hectare for 20 minutes, and they took notes on the squirrels they saw, including:

  • Fur Color
  • Sounds
  • Tail Twitches
  • Activities
  • Interactions with Humans
  • Age
  • Time of Sighting
  • Fun Stories About the Squirrels

...and much more.

Central Park

Manhattan's Central Park

For our project, we wanted to tackle a light-hearted topic that would re-inspire delight in nature, particularly due to the mundane routine of pandemic life.
Thus, we chose to analyze the Squirrel Census.

Join us in learning more about the census takers' delightful experiences and the rambunctious squirrels of Central Park.

squirrel sleeping

Explore the census takers' experiences

When hovering over a story, look at the map to see where it took place.

Story Topics:

Filter the squirrel sightings on the map

You can click on the dots!

Squirrel's Primary Fur Color

Squirrel's Reaction to Humans

Time of Sighting

Squirrel Location

Story Category:

Over half of the census takers' stories were positive

Use the drop down to view the effect various categories on sentiment

Where are we getting this data from?
We used a sentiment analysis package to better understand the emotions behind the census takers' stories. As you can see, the stories are majorly positive!

We split the data by categories that might affect census taker’s moods, such as observing squirrels vs. other animals. Overall, Accidental Poems are the only class with a noticeable difference, with non-poem stories having 15% more of the total proportion being positive than the Accidental Poems. All the other classes range from 51-58% positive stories, which is a majority. Squirrel stories have 8% more positive proportions than non-squirrel stories.

The census takers used certain words more frequently than others

Instructions: Click on the different words to read a random story. P.S. Some of them are quite amusing!

Take a look through the words and you’ll notice lots of action words, like chasing, running, and playing, and some unique words like “foraging” and “hectare”. Out of the 50 most frequent words, 22 are nouns, 10 are verbs and 7 are adjectives.

Trivia Time!

Now that we've analyzed the census takers' stories, we'll turn to the squirrels themselves - see if you can answer these squirrel trivia questions!

Eastern gray squirrels are the most common squirrels in Central Park.

True! As shown before, gray squirrels heavily populate Central Park.

Dogs were ranked first as America’s favorite pet in the 1700s.

False! In fact, Americans used to keep squirrels as pets due to their friendly, playful personalities and easy upkeep.

The most common sounds that Eastern gray squirrels make are "quaas".

False! “Kuks”, a generic sound alarm, is the most common squirrel sound. You’ll see this below.

squirrel pouncing

Squirrels moan to warn other squirrels about aerial predators (i.e. hawks!).

True! In fact, moans hide the squirrel’s location - a key difference from “kuks” and “quaas”.

When used together, tail movement affect the meaning of squirrel sounds.

True! Squirrel tail movements help specify the type of threat the squirrel is concerned about.

The number one activity that squirrels spend the most time on is eating nuts.

False! Squirrels spend more time foraging food like nuts!


Squirrels show personality through their behavior

Squirrels who approach or ignore humans have certain patterns of activities, sounds, or tail movements.

Click the dropdown to filter a sample of 90 squirrels by various attributes.


Pay special attention to the approaching squirrels! They were spotted running and climbing, and tend to Kuk.

“Kuks” are the most common sound as they are a generic squirrel alarm. “Quaas” warn about terrestrial threats (dogs, cats) while “moans” signal aerial threats (hawks). Tail flags affect the meaning of squirrel sounds while tail twitches are more generic. Learn more in this Wired article.

The bar vis below shows frequencies on the entire dataset, not just the sample. Note that some squirrels may have been spotted doing multiple activities or no activities at all.

For the census-takers, squirrel-watching was a highly enjoyable experience.

“Being part of the project is about more than counting squirrels. ...It tunes the person to the environment, and makes you notice things that you otherwise wouldn’t. Listen closely enough, and you can hear [the squirrels] rustling in the bushes, making the “kukking” noise, or crunching on a nut.”
- Jamie Allen, Squirrel Census Founder

“Today was a fine day for a squirrel census and I very much appreciated the opportunity -- it was a very peaceful experience. Counting squirrels makes your troubles disappear into nature. Thanks!”
- Census Taker

"The friendships that were quickly made. This experience of active meditation. It was like fishing[,] only on land. The notion of watching squirrels while people were inquisitively watching us was fun, like having a secret in an open public forum."
- Census Taker

For the census takers, squirrel-watching was peaceful, meditative, and calming. On the next page, you'll get to step into their shoes and learn about what walking through Central Park would be like!

Learn about the wildlife you'd see on a walk in Central Park!


  • Using the tool bar on the left, draw line segments (a walk) on the map.
  • Stay within the bounds of Central Park.
  • The shorter your line segments, the more accurate your walk information will be.
  • Click "Finish" on the tool bar when you are ready to learn about your walk!
Your Walk

Max # of Squirrels You May See:

Would a Squirrel Approach You?

Walking Distance:

Other Animals You Might See:

Click "Heat Map" to see which hectares have the most squirrels. Then, try clicking on the heat map!

Squirrel Count Legend:

Squirrel 1

Wherever you are, take a walk and pay attention to the wildlife around you. It just might make your day!

Jada Lee

Jada Lee

Jada is a senior at Harvard studying Anthropology and CS. More importantly, she is an avid squirrel enthusiast. Hailing from MN, she grew up seeing countless squirrels in her yard!

Elizabeth Ling

Lizzy Ling

Lizzy is a sophomore at Harvard studying CS and Statistics. She always enjoys visiting Central Park when in New York City and has gained a new appreciation for squirrels.

Iris Su

Iris Su

Iris is a sophomore at Harvard studying Economics and CS. She is passionate about playing frisbee in parks with her friends while watching squirrels scramble around!


  • Data Set #1: https://data.cityofnewyork.us/Environment/2018-Central-Park-Squirrel-Census-Squirrel-Data/vfnx-vebw
  • Data Set #2: https://data.cityofnewyork.us/Environment/2018-Central-Park-Squirrel-Census-Hectare-Data/ej9h-v6g2
  • Data Set #3: https://data.cityofnewyork.us/Environment/2018-Central-Park-Squirrel-Census-Stories/gfqj-f768
  • Squirrel Images: https://www.freepik.com/free-vector/cute-red-furry-squirrel-set_8609088.htm
  • https://www.thesquirrelcensus.com/
  • https://www.bloomberg.com/news/articles/2019-06-24/how-many-squirrels-are-in-nyc-s-central-park
  • https://www.washingtonpost.com/local/learn-to-speak-squirrel-in-four-easy-lessons/2012/04/09/gIQAV8Jr6S_story.html
  • http://robertgrantstats.co.uk/drawmydata.html
  • http://nymag.com/news/features/squirrels-2014-2/