Results of 2023 Denver-Boulder City Nature Challenge are in!

The City Nature Challenge is a yearly event for folks in cities all over the world to observe and document biodiversity in their own backyards. To participate, people make observations of any organism – plant, animal, insect and more – on iNaturalist for a few days in late April to early May. This is followed by a short identification phase—where a community of nerdy naturalists will work on identifying all species observed.

For this year’s global challenge, there were almost 1.9 million observations of over 57,000 species, with 2,570 species considered rare, endangered or threatened. These observations were made by more than 66,000 people from 482 cities in 46 countries around the world. The leading city for numbers of observations, species and observers was La Paz, Bolivia with 126,000+ observations of more than 4,600 species! Congrats to La Paz!

In the Denver-Boulder metro area, more than 3,500 observations were observed by 457 people of 666 species. The organisms observed were mostly plants, insects and birds. Fun species observed included black bear, bobcat, beaver and even northern spleenwort (Asplenium septentrionle), a vulnerable plant species in Colorado. 

Thank you to everyone who participated in this year’s City Nature Challenge. Here at Denver Botanic Gardens, we have been selecting our favorites, in categories such as most colorful to cutest! Who knows, your observation could even be selected for a prize in one of these categories.

We are looking forward to participating with you next year in the 2024 City Nature Challenge.