City Nature Challenge 2023

A squirrel in a park, standing up and looking directly at camera

Photo by Austin Tate on Unsplash

Let’s show off how amazing our cities can be for wildlife this spring!

City Nature Challenge is an annual four-day global 'bioblitz' nature hunt, to assist in recording and protecting wildlife in urban areas. Every year, cities all over the world take part in friendly and fun competition to see who can gather the most observations of nature and find the most species.

City Nature Challenge 2023

City Nature Challenge is back! Continue to check back for more information closer to the date.

City Nature Challenge returns 28 April - 1 May 2023. In the meantime, you can use the iNaturalist app all year round to document the nature that thrives in your neighbourhood.

At a glance

Discover wildlife in your local area and help scientists understand more about urban nature.

Type of activity: Outdoors

Who can take part? Everyone

When? Friday 28 April - Monday 1 May 2023

Where? Towns and cities around the UK, and around the world!

How long will it take? About two minutes per observation

Cost: Free

A global event

In City Nature Challenge 2022 almost 1.7 million observations were made of over 50,000 species with over 67,000 people taking part across the world - an astonishing collective effort that we can eclipse in 2023 with your support.

This year, individuals, families, and community groups in over 400 cities globally are invited to look for nature in their gardens, parks, public spaces or homes and join this worldwide effort to record as much wildlife as possible between 28 April and 1 May 2023.

It’s simple, fun and anyone can join in

All you need is a smartphone and the iNaturalist mobile app. Share a photo with the app and it will assist you to identify and record the species you find. Each species record is known as an observation, and all observations made during the event in participating areas will count towards City Nature Challenge.

You can then join  other nature enthusiasts to work together to formally identify the records before they are shared for inclusion in local and national wildlife databases, which support nature conservation efforts.

hands with camera phones taking photos of a bright red toadstool

Photo by Nico Baum on Unsplash

How to take part

All you need to get started is a smartphone with the FREE iNaturalist app downloaded, or a camera to take photos of what you see and upload to their website later. Instructions: How to use iNaturalist doc (PDF 4.4MB)

  • See it
    Find nature: during the event, explore in and around your home, in local parks and road verges, on the way to school or work, gardens or courtyards - anywhere you might find living organisms.
  • Snap it
    Take a picture: of wild plants, animals, or fungi that you find. If they are not wild, for example domestic animals or planted flowers, be sure to mark them as captive/cultivated.
  • Share it
    Share your observations: record what you find by clicking ’observe’ or ‘+’ on the iNaturalist app or upload your photos to
  • Tallying the results
    In the week after the event everyone's observations are identified and counted. You can help to identify other people’s wildlife observations and learn more as others identify your wildlife observations.

The worldwide competition results will be revealed at on Monday 8 May 2023.

Activities in London

Organisations across London are running events as part of City Nature Challenge. Check back here closer to the date for a list of events.

If you are interested in organising an event in 2023 or future years, please email Jessica Wardlaw ( for more information and resources.

How will my observations help science?

The information collected will create a valuable snapshot of the variety of wildlife that lives in cities. Knowing what species live in cities, and where they are, helps us to study and protect them. Documenting nature on a city-wide scale allows us not only to learn about the variety of nature in cities, but also about the sustainability of valuable ecosystems that thrive in cities.

With the world's wildlife facing unprecedented declines, and as urban areas expand, it has never been more important to make our towns and cities healthy and sustainable places to live side-by-side with nature. The only way to do that is for people to team up - including you!

How we all did in 2022

Thank you to everyone that took part in City Nature Challenge 2022. In London over 300 community scientists recorded a grand total of 4,436 observations of 1,087 species.

You can read about the highlights and results from the UK on our blog post​, and on the City Nature Challenge website.

Resources for educators

We encourage schools to take part. The City Nature Challenge organising team has produced some resources to support teachers and educators.

City Nature Challenge around the UK

Cities and regions across the whole UK have signed up to take part in the Challenge. Check out the UK Leaderboard  to find out which cities are taking part. During the event, you’ll be able to watch live results from cities involved and see which city has recorded the highest number of species and number of people taking part.

Your city or region isn’t competing this year? No problem! Any iNaturalist wildlife sightings during the event will still count towards the UK records and help fill in the map of where nature is living in your region.