City Nature Challenge 2026

The City Nature Challenge (CNC) is a four-day bioblitz where cities around the world record as much wildlife as possible.

Wildlife is measured by the total number of observations, the number of species and the number of people making observations. CNC is also a great way to engage in community science and help document the biodiversity of our urban areas.

The event takes place using the iNaturalist website and app. Any observation photo, geotagged from anywhere in the seven-county Philadelphia area (Philadelphia, Delaware, Montgomery and Bucks counties in Pennsylvania, and Camden, Gloucester and Burlington counties in New Jersey) and time-stamped during the four days of the event, will count toward Philadelphia’s tally. Follow the Philly area’s progress on the CNC Philly iNaturalist page: City Nature Challenge 2026: Greater Philadelphia Area · iNaturalist

Explore along with the Academy community through our home on iNaturalist, the Academy Naturalists project group!

Visit the CNC Philly home page for detailed instructions on how to participate. This annual event is organized by Natural History Museum of Los Angeles County and California Academy of Sciences.

How to Get Involved
Download iNaturalist – Create a free account in the app or at iNaturalist.org.
Make Observations – Take photos of your findings anywhere in the Challenge Area between April 24 and April 27 and add to iNaturalist.
Join an Event or Explore on Your Own– Attend an in-person event led by naturalists and community scientists or photograph wild species in your neighborhood, local park or backyard and upload them to iNaturalist.
Spread the Word – Invite friends, family, classrooms, and community groups to join the challenge.
Identify – Continue to upload and identify your photos on iNaturalist until the results are tallied on May 9.

The Conservatory at Laurel Hill Cemetery West
Saturday, May 9, 2026
10 a.m. – 1 p.m.
225 Belmont Ave., Bala Cynwyd

Join Laurel Hill and ANS staff along with naturalists, hobbyists and professionals as we learn how to identify species in the cemetery and arboretum. Bring the whole family for iNaturalist tutorials, interactive games, basic exploration of taxonomy and classification, with snacks and conversation about the importance of biodiversity and environmental literacy.

The City Nature Challenge allows all to explore local ecosystems, build observation skills and contribute to real scientific research. The Academy partners with community organizations and public agencies to encourage schools, educators, families and neighborhood groups to participate and make City Nature Challenge 2026 one of Philadelphia’s most inspiring and successful community science events yet.

As Philadelphia celebrates the 250th anniversary of the United States, the City Nature Challenge offers a powerful reminder that the story of this city is still being written — not only in its historic landmarks and neighborhoods, but also in its rivers, forests, meadows and the countless species that call it home.