City Nature Challenge 2025
25 April 2025 - 28 April 2025
Region(s): Nationwide, Auckland, Wellington, Canterbury
Type(s): national Events, citizen Science
Become a community scientist by capturing observations of biodiversity using the iNaturalist app. Join the iNaturalist project for your city or area, and head outside to snap photos of plants, fungi and wildlife
Cities around the world collaborate to share observations of nature in the 2025 City Nature Challenge.
Started in 2016 as a competition between Los Angeles and San Francisco, the City Nature Challenge has grown into an international event. The City Nature Challenge is an annual four-day global bioblitz at the end of April, where cities are in a collaboration-meets-friendly-competition to see what can be accomplished when we all work toward a common goal.
The 2025 City Nature Challenge takes place in 2 parts:
25 April–28 April: Taking pictures of wild plants and animals
29 April–4 May: Identifying everything found
Results will be announced on Monday 5 May, 2025.
Download the iNaturalist app to your mobile device. Use the app to upload photos of organisms to iNaturalist NZ, and our friendly community will help you identify them. It's as simple as that! You can also add observations straight to iNaturalist.NZ on the web (www.inaturalist.nz) if you prefer.

iNaturalist NZ – Mātaki Taiao
This OCS project can identify plants and animals or act as a way of collating data about the diversity of plants and animals in your area.
Has your city registered? See below to find your place and what events are on. If we have missed any locations, please do email us enquiries@sciencelearn.org.nz:
Tāmaki Makaurau/Auckland on iNaturalist
Pōneke/Wellington Region and Te Upoko o te Ika (Wellington Region) on iNaturalist.
Ōtautahi/Christchurch and Ōtautahi/Christchurch on iNaturalist.
For more information and to register: https://www.citynaturechallenge.org/ or https://inaturalist.nz/projects/city-nature-challenge-2025-bend.
Related content
Find out more about the iNaturalist citizen science project.
The article The war on weeds, describes how school students helped scientists combat the spread of weeds using iNaturalist.
The Hub has extensive resources about New Zealand’s native flora, fauna and fungi and why conservation and restoration are important. Find out more about biodiversity, or check out our topic collections: estuaries, plants, birds, reptiles and amphibians, butterflies and moths, fungi and invertebrates.
Here are some planning tips for when you intend to use a citizen science project with your students.