Ostrava Celebrates Success in Global City Nature Challenge
Ostrava has achieved outstanding results in the 10th annual City Nature Challenge, a global biodiversity monitoring project that this year brought together 669 cities from 62 countries across six continents. Ostrava ranked 4th in the world and emerged as the most successful city in both Europe and the Czech Republic.
Graphic design by the Ostrava Museum and the Statutory City of Ostrava for this year's competition edition. Photo: MMO
This remarkable achievement was made possible thanks to the efforts of hundreds of enthusiastic observers — members of the public and primary school students alike — who collectively submitted over 100,000 observations of local wildlife through the iNaturalist app during the four-day event.
The City Nature Challenge, held this year from April 25–28, aims to document urban biodiversity worldwide. For the first time in the event's history, more than 100,000 participants took part globally, recording an impressive 3,297,129 observations and identifying 79,877 species — including over 3,300 rare or endangered ones.
“In the Czech Republic alone, we recorded 141,575 observations with more than 2,200 participants. In Ostrava, 1,200 people took part — including schoolchildren, who went out into nature as part of their science lessons,” said project coordinator Tomáš Ocásek. Despite this being only Ostrava’s second year in the competition, the city logged 100,260 observations — a dramatic increase from last year — securing its position at the top in the Czech Republic and Europe, and placing it 4th globally.
The most commonly observed species across the Czech Republic included the common dandelion and the daisy, while among animals, the firebug and garden snail were frequently spotted. “The dandelion turned out to be the most observed species globally,” noted Aleš Boháč, Deputy Mayor for the Environment.
Following Ostrava, Prague ranked second in the Czech Republic with 27,480 observations, while the Uherské Hradiště region came third with 5,478, and Brno followed in fourth place with 4,402.
“Every single observation matters. Even seemingly ordinary species provide scientists with valuable data about biodiversity changes. The insights gathered are crucial for nature conservation worldwide,” added Ocásek.
The City Nature Challenge is a prime example of the power of citizen science. With the enthusiasm and collaboration of thousands of people across the globe, a unique database is created each year, helping researchers monitor biodiversity changes in real time, especially in urban environments. In the Czech Republic, more than half of the recorded species were plants, with insects making up a quarter of all observations, followed by fungi and birds.
“I would like to thank all the volunteers who contributed to Ostrava’s fantastic result. We outperformed major cities like Hong Kong, Rome, and São Paulo, and greatly exceeded last year’s achievements. I hope our observers enjoyed their time in nature, learned something new, and shared their knowledge with others through technology,” concluded Deputy Mayor Aleš Boháč, under whose patronage the event was held.
Next year’s City Nature Challenge will take place from April 24 to 27, 2026.