City Nature Challenge

City Nature Challenge 2021 logoCity Nature Challenge 2021
Friday, April 30–
Monday, May 3

The 2021 City Nature Challenge is almost here!

As community science initiatives increase in popularity, this year’s sixth annual City Nature Challenge is set to take place in cities throughout the world.

The global event, co-organized by San Francisco’s California Academy of Sciences and the Natural History Museum of Los Angeles County, calls on current and aspiring citizen scientists, nature and science fans, and people of all ages and backgrounds to observe and submit pictures of wild plants, animals, and fungi using the free mobile app iNaturalist.

From Friday, April 30 to Monday, May 3, participants can upload their observations to the app, with identifications happening from Tuesday, May 4 to Sunday, May 9. Final results will be announced on Monday, May 10.

Here's how to participate:

  1. Download the FREE iNaturalist app. Find instructions for downloading the app on the iNaturalist website or go directly to the app store.
  2. Take photos of plants, animals, insects, and other life forms. You can do this anywhere across the bi-state* region.
  3. Upload your images on the greater St. Louis region's iNaturalist page.

* Counties representing the greater St. Louis region in the 2021 City Nature Challenge: Missouri - Crawford, Franklin, Jefferson, Lincoln, St. Charles, St. Francois, St. Louis City, St. Louis County, Warren; Illinois – Bond, Calhoun, Clinton, Jersey, Macoupin, Madison, Marion, Monroe, St. Clair.

This year’s City Nature Challenge is not a competition. We want to embrace the collaborative aspect of sharing observations online with a digital community, and celebrate the healing power of nature as people document their local biodiversity to the best of their ability. We want people around the world to have the opportunity to participate, while still following all federal and local recommendations to keep communities safe.

In light of the ongoing pandemic, there will be no organized gatherings for groups of participants to make observations together. However, we have created a map of nearby nature sites for you to explore independently, with members of your household, or with friends while respecting public health guidelines!

Find a nearby nature site to explore using this map!

As a participant, it is up to you where to go to take your observation photos! Do only what feels safe for you and your family. Remember to follow all government health-safeguarding regulations. If you can’t get out to one of our region’s unique nature sites, you can still participate in your backyard! Being outdoors can help to lower stress levels and increase overall feelings of well-being, so take care of yourself by being in nature if you're able.

Stay connected by following our St. Louis City Nature Challenge Facebook page and St. Louis City Nature Challenge 2021 Facebook Event.

Here are some suggestions on how to explore no matter where you are:


  • Did you know that there are on average 93 species of arthropods living in houses? What can you find in your house? What can you see through your windows?
  • Once the City Nature Challenge starts, help us identify what's being found in the St. Louis Region! 
  • Can we go through ALL the observations (not just CNC!) that have already been made in the St. Louis Area but aren't Research Grade yet? 
  • During April 30–May 3, hold virtual ID parties with your friends!

In Backyards: 

  • Put up bird feeders or moth lights, or put down cover boards to bring nature to you! 
  • What are the wild plants growing in your backyard?
  • What insects or other creatures are using the cultivated plants in your backyard as habitat or a food source?

At a Nearby Nature Site:

  • Is there a park or historical site on the map you didn’t know was in your neighborhood? This is a great opportunity to check it out!
  • Can you find a surrogate species? Check out this publication from the City of St. Louis to learn about indicator species in the region.
  • Challenge: find a woody plant, herbaceous plant, an invertebrate, a herp, a bird, and a mammal.

For more information visit:

Stay safe, hang in there. We can't wait to see what you find in your houses, in your backyards, along sidewalks, in parks. Know that people all around the world are joining you in documenting nature in whatever way they can, even during these uncertain times.


A Community Initiative to Promote, Protect and Plan for Biodiversity Throughout the Greater St. Louis Region

Supported by Ameren Missouri

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Nearby Nature

Nearby Nature map

Spend more of your time exploring and stewarding St. Louis' great outdoors. Download our map featuring more than 50 places to visit!