With as many as 482 cities in 46 countries around the world, this 2023 edition of City Nature Challenge was the most participatory ever.

During April 28-May 1, 2023, City Nature Challenge produced a total of 1,870,763 observations made by 66,394 citizens. The observations covered 57,227 species of animal plants and fungi recognized with the help of 15,308 identifiers.

Participating were 11 cities from Oceania almost evenly divided between Australia and New Zealand, 42 from Asia, 97 from Europe, 24 from Africa, 308 from the American continent including 128 from the USA, 43 from Canada, 77 from Mexico and 60 from various South American states, with La Paz in Bolivia once again the overall winner of the competition.

The participation of Roman citizens, thanks in part to an effective promotional campaign, was higher than expected, despite the fact that weather conditions in the Rome Capital Metropolitan City area were not favorable especially on the last day of competition. More than 40 events were organized in the area, campaigns of observations open to the public, or reserved for schools and specific groups (such as the divers of the Secche di Tor Paterno).

By total number of observations Rome is fourth in Europe and 26th in the world, with 15,318 observations, of which 14,316 can be verified and 4,275 have already been validated at the research level. Rome is surpassed by two Austrian cities Graz and Salzburg and, in Italy, only by Milazzo, which already in the two previous editions had achieved positions of absolute world prestige. This proactive and exuberant Sicilian reality is to be warmly congratulated.

A total of 2089 largely verifiable (i.e., accompanied by photographs or audio) ‘species’ were observed in Rome, of which as many as 944 were already usable for research purposes. Rome ranked 27th in the world and 5th in Europe for number of species identified.

By number of participants, Rome ranked 20th in the world and first in Europe, with 657 citizens making and sharing observations over the four days of competition. A nod to the ‘quality’ of participation: at least 100 citizens made 30 observations with 15 different species. This is a very significant figure as it testifies to the efforts made to involve citizens, with a view to scientific dissemination and environmental awareness.


Locandina CNC2023 Roma


The participation of the Metropolitan City of Rome Capital in the international competition was promoted by the National Academy of Sciences known as Accademia Nazionale delle Scienze detta dei XL, and supported by the Castelporziano Presidential Estate Service, Carabinieri Biodiversity Regiment, National Biodiversity Network, CREA, Lazio Region, Metropolitan City of Rome, Roma Capitale – Department of Agriculture, Environment and Waste Cycle, Roma Natura, LifeWatch Italia, Legambiente, WWF, Federparchi, Lipu, CURSA, Sapienza University of Rome, Botanical Garden, Department of Biology of Tor Vergata University, University of Roma Tre, Citizen Science Association Italy, Italian Society of Biogeography, Italian Lepidopterological Association, Italian Entomological Society, Roman Association of Entomology, Roman Natural Science Society, Circolo Speleologico Romano, National Association of Natural Science Teachers (ANISN), Bioparco Foundation of Rome, Museo Civico di Zoologia, Parco dell’Appia Antica, Parco di Veio, Riserva Naturale Tevere Farfa, Museo del Fiume di Nazzano, Parco dei Castelli Romani, Parco naturale regionale Bracciano Martignano, Riserva Naturale Regionale di Monterano, Parco dei Monti Simbruini, Riserva Naturale Regionale Monti Lucretili, Mediterraid Cammina.

CNC is a friendly competition held annually among more than 450 cities around the world that compete with each other through the participation of scientists and volunteers, who on competition days, are asked to collect and report the most data on urban and peri-urban biodiversity. CNC is one of the most important global Citizen Science events conceived in 2016 by the California Academy of Sciences and the Los Angeles Museum of Natural History.

Citizen Science initiatives such as this one are particularly important both because of the contribution they can make to the advancement of scientific knowledge through the collection, analysis, and interpretation of data in a shared way; and because they propose the involvement of the citizenry, families, and young people with relevant spin-offs in terms of environmental awareness of the value of biodiversity in urban ecosystems.

Follow Facebook e Instagram City Nature Challenge 2023 Roma

Intervista Radio 1 Rai prof. Valerio Sbordoni (min. 13.30)

Intervista Radio 1 Rai dott.ssa Giulia Bonella, direttore del Servizio Tenuta Presidenziale di Castelporziano (min. 5.15)

Rassegna stampa CNC Roma 2023

I Bioblitz organizzati dai partners CNC Roma 2023

Mappa dei Bioblitz

Il calendario dei bioblitz Roma 2023