City Nature Challenge 2024

March 22, 2024 Jennifer Ramp Neale, Ph.D. , Director of Research & Conservation

Join your community in documenting biodiversity during the City Nature Challenge! Having started as a friendly competition in California, the global challenge, now in its 9th year, has grown to include more than 500 cities in 2024. The City Nature Challenge is an event that consists of two phases – the Observation Phase – where community scientists use the iNaturalist smartphone app to record observations of nature in their city, and the Identification Phase where nature enthusiasts and experts work to link species identifications to the observations. 

The City Nature Challenge 2024 
Observations: April 26 – April 29
Upload and Identification Phase: April 30 – May 5

Person taking photo of plant with mobile phone

Denver Botanic Gardens is the lead organizing institution for the Denver-Boulder metro area which encompasses the greater seven-county metro area (Adams, Arapahoe, Boulder, Broomfield, Denver, Douglas and Jefferson). All iNaturalist observations of wild plants and animals made during the observation period and uploaded before the end of the Identification phase are automatically included in our 2024 City Nature Challenge iNaturalist project. They are also added to the Global Umbrella City Nature Challenge project, where you can see the >500 cities participating in 2024 under the Umbrella project. So even if you don’t live in the Denver metro area, you may be in a city that is participating. 

Globally the 2023 City Nature Challenge saw 1.8 million observations of more than 57,000 species and 66,000 participants. La Paz, Bolivia had amazing participation with 126,000+ observations of more than 4,600 species!

In 2023, the Denver-Boulder metro area saw more than 3,500 observations of 666 species made by 457 participants. We’re hoping to have more than 500 participants this year. We give out prizes to participants in a variety of categories from best plant photo, to most colorful, and most bizarre. So, join us in 2024 by adding your observations.

Learn more about the City Nature Challenge, how to use iNaturalist, and find details on local events on our web site. 


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