Are you ready for the City Nature Challenge?

Nature // April 28, 2021

Join Friends of the Wissahickon for the third annual Philadelphia City Nature Challenge! Between April 30 and May 3, 2021, Philadelphia and its adjacent counties will be competing against other cities in the world to see who can find the most species in their regions – and along with thousands of citizen scientists worldwide, FOW staff and volunteers will be working to document biodiversity in the Wissahickon using the free app iNaturalist.

Participating in citizen science events like the City Nature Challenge is hugely important for increasing our understanding of biodiversity in the park. The large amounts of data give scientists a good idea of what lives where, and whether different ecosystems are doing well or need some help – for example, citizen science data already helps inform FOW where to prioritize habitat restoration projects. Finally, popular citizen science events like the City Nature Challenge and the Audubon Christmas Bird Count have also been influential in getting a new generation of future naturalists involved in science, so these spaces can be conserved for generations to come.

Get started on iNaturalist!

Making an observation on iNaturalist is as easy as downloading the free app, taking a picture, and uploading it. Don’t worry if you don’t know what something is – the app offers helpful suggestions for you to choose from, and later on, skilled naturalists go through the data to verify observations. With time and practice, spotting common species will start to feel natural.

If you’re not sure where to start looking for what, we hope you’ll check out our species scavenger hunt for Andorra and Houston Meadows in the park – it’s filled with some common and less common flora and fauna in the park and is a great activity for kids.

Keep track of the challenge in the Wissahickon.

You can see up-to-the-minute species observations and locations in the Wissahickon on our 2021 City Nature Challenge page here. We’ll also be doing live videos with some local naturalists in the park during the challenge, and posting our favorite #observationoftheday on social media at @FOWissahickon.

Last year, volunteers made 2,470 observations of 514 species in the Wissahickon – this year, we’re hoping we can get above 3,000 observations with your help!

Go for a nature hike – and log some habitat monitoring hours!

Our partners at the Wissahickon Environmental Center are leading multiple in-person, socially distanced nature hikes to learn how to start observing during the challenge! There’s still time to sign up, so check them out here.

Also, you’re planning on spending time doing solo observations, don’t forget to log your hours spent observing for volunteer recognition! Get credit for your time and learn more about our year-round habitat monitoring program at

See you out in the Wissahickon!