Will Ostrava Build on Its Success in the City Nature Challenge?
Anyone can join this worldwide challenge—families with children, students, and seniors alike. A supporting public program will also be available.
The City Nature Challenge (CNC) is a global citizen science initiative aimed at mapping urban biodiversity. It was founded in 2016 in the United States and now involves hundreds of cities across six continents.
“The main goal of the City Nature Challenge is to show that nature in cities is unique and rich. Thanks to the initiative of the Ostrava Museum, Ostrava will participate for the third time and aims to build on last year’s success. With strong engagement from residents, the city ranked fourth globally and became the most successful city in Europe and the Czech Republic in the 10th edition of the project. A total of 669 cities from 62 countries across six continents took part. For the first time, more than 100,000 observers worldwide documented biodiversity in their surroundings using the iNaturalist app. Ostrava residents were among them, including active participation from local primary schools. I believe participants enjoyed their time in nature and will continue observing it beyond the project period,” said Aleš Boháč, Deputy Mayor of the City of Ostrava.
According to project coordinator Tomáš Ocásek from the Ostrava Museum, no special expertise or skills are required to participate:
“All you need to do is download the free iNaturalist app on your phone and take photos of plants, wild animals, insects, or fungi within Ostrava—perhaps during a walk in a forest or park. There is no limit to the number of photos, but they must be taken and uploaded between April 24 and 27.”
The iNaturalist app helps identify recorded species. To ensure observations count toward the final results, participants should upload clear, detailed photos that allow accurate identification.
“Photos of people, pets, zoo animals, aquarium species, or potted plants are not included. Only species living freely in the urban environment should be documented. The data collected by the public is also used for scientific purposes,” Ocásek adds.
Participants can explore individually in their free time or join organized public events. Experts from the Ostrava Museum, Zoo Ostrava, the Faculty of Science of the University of Ostrava, and the Silesian Ornithological Society will lead guided outings and assist with documenting nature.
“The public program begins on Friday, April 24, with a walk around the ponds below Bedřiška. On Saturday, April 25, visitors can join a guided tour at the zoo or a walk to Landek. Sunday’s program includes early morning birdwatching in the Rezavka nature reserve and a walk to the Michálka spoil heap. All events are free of charge except for the Zoo Ostrava program, where standard admission applies,” the coordinator adds.
A full overview of the accompanying program and all relevant information is available at Ostravian project web.
After the observation phase ends, data verification and species identification will take place in the app from April 28 to May 10. The global results—including the total number of observations and the most interesting photos from around the world—will be announced on May 13.
Practical Information
The City Nature Challenge 2026 takes place worldwide from Friday, April 24 to Monday, April 27, 2026. The event is supported by the City of Ostrava and held under the patronage of Deputy Mayor Aleš Boháč.
Main organizer in Ostrava: Ostrava Museum
Project partners and participating institutions: Library of the City of Ostrava – Zálom branch, Faculty of Science of the University of Ostrava, Silesian Ornithological Society, Korunka Leisure Centre Ostrava, VSB – Technical University of Ostrava, Zoo Ostrava
Global website
City Nature Challenge Ostrava website
Facebook event