2025  3,310,131 Observations 73,765 Species 102,945 People   CNC 2025 Map  

Past Results

Invented by community science staff, Lila Higgins at the Natural History Museum of Los Angeles County (NHM) and Alison Young and Rebecca Johnson at the California Academy of Sciences (CAS), the City Nature Challenge is an international effort for people to find and document plants and wildlife in cities across the globe. It’s a bioblitz-style competition where cities are in a friendly contest with each other to see who can make the most observations of nature, who can find the most species, and who can engage the most people.   How it all got started  Started in 2016 for the first-ever Citizen Science Day, the community science teams at NHM and California Academy of Sciences dreamed up the City Nature Challenge as a fun way to capitalize on their home cities’ friendly rivalry and hold an event around urban biodiversity. The first City Nature Challenge was an eight-day competition between Los Angeles and San Francisco, engaging residents and visitors in documenting nature to better understand urban biodiversity.     In its first year, over 20,000 observations were made by more than 1,000 people in a one-week period, cataloging approximately 1,600 species in each location, including new records for both areas. During the 2016 CNC, there was so much excitement and interest from people in other cities that the organizers knew they couldn’t keep the fun just to themselves. In 2017 the City Nature Challenge went national, and in 2018, the CNC became an international event!     City Nature Challenge Leadership     Lila Higgins (they/them)  Co-Senior Manager, Community Science and City Nature Challenge co-founder Natural History Museums of Los Angeles County  Lila, who joined the Natural History Museum of Los Angeles County in 2008, is an informal educator with almost two decades of experience in museum education and community science programming. Their fascination with nature started early; they grew up on a farm in the U.K. where they spent their time chasing butterflies, playing in hollow trees, and pretending to be a badger. Lila was a lead educator on the Museum’s newest nature-themed exhibits—the Nature Lab and Nature Gardens. They also authored the book Wild L.A. and co-founded the global community science event called the City Nature Challenge. They hold a bachelor’s degree in entomology from UC Riverside and a master’s degree in environmental education from California State University, San Bernardino.     Rebecca Johnson (she/her)  Director, Center for Biodiversity and Community Science and City Nature Challenge co-founder California Academy of Sciences  Dr. Rebecca Johnson directs the Center for Biodiversity and Community Science and the Thriving California Initiative at the California Academy of Sciences. She and her team focus on designing equitable, inclusive, and meaningful events and campaigns to gather biodiversity data and mobilize those data to understand climate change and stem biodiversity loss in California. She is passionate about building partnerships and coalitions around place-based nature connection, biodiversity data use, and on-the-ground action for positive change. She co-founded the City Nature Challenge and Snapshot Cal Coast. Dr. Johnson is on the California Biodiversity Network Steering Committee and leads the Academy’s biodiversity work with the City of San Francisco. She is the board chair for Bay Nature Magazine and a TOGETHER Bay Area board member. Dr. Johnson earned her B.A. in Integrative Biology from the University of California, Berkeley, her M.A. in Systematics and Ecology from San Francisco State University, and her Ph.D. in Ecology and Evolutionary Biology from the University of California, Santa Cruz. She lives in San Francisco with her family.      Amy Jaecker-Jones (she/her)  Program Manager, Community Science Program and CNC Managing global organizers Natural History Museums of Los Angeles County  Amy joined the Community Science Program at the Natural History Museum of Los Angeles County in 2018. Her primary responsibility is coordinating the City Nature Challenge at the local and global levels. Other projects she has worked on include the Backyard Bat Survey, co-creating a bilingual pollinator guide with a local elementary school, and field-testing community science kits at several Los Angeles County parks. Amy is a California Naturalist, a Certified Interpretive Guide, and a graduate of Occidental College.     Sam Tayag (they/them)  Program Manager, Community Science Program and CNC Managing global organizers Natural History Museum of Los Angeles County    Sam joined the museum in 2021. Their roots in community science grow from field research with their Grandma as a child in the lahar fields of the Mt. Pinatubo volcanic eruption. There they saw the power of community knowledge and mutual aid with the land applied to scientific research. They work to support community relationships to the land and natural science as a California Naturalist, former nurse, community organizer, and . They center their family’s traditional Indigenous ways of learning and connecting, including their experience as a parent to an awesome young child.     Olivia VanDamme (she/her)  Coordinator, Center for Biodiversity and Community Science and CNC Managing global organizers California Academy of Sciences    Olivia started at the California Academy of Sciences in 2019. She is a new member on the community science team, and excited to support City Nature Challenge! She previously supported Science Action Club, a community science based international STEM program providing out-of-school time programs with professional development and science kits. Olivia has been recognized by Justice Outside for her extraordinary leadership and commitment to diversity, equity and inclusion in nature, as an alumna of their Rising Leaders Fellowship program. She holds a BA in Geography and Latin American Studies from California State University, Chico. As a Latina surfer and dedicated ocean advocate, Olivia volunteers with Brown Girl Surf, was the previous Program Director for City Surf Project, and has worked on several environmental justice initiatives at government agencies such as the California Coastal Commission. She currently serves as an Advisory Board Member for the Explore the Coast grant program through the California State Coastal Conservancy.     Jessica Carver (She/Her)  Associate Manager, Center for Biodiversity and Community Science and City Nature Challenge Managing global organizers California Academy of Sciences    Jessica joined the Academy in 2025 as a Community Science Associate Manager. Jessica brings a background in environmental education, program management, and workforce development. Before joining the Academy, Jessica managed the SEI Climate Corps Fellow Program and coordinated the County of Marin's Zero Waste Schools Program. Earlier in her career, she worked at the San Lorenzo Museum of Natural History and the University of California, Santa Cruz Kenneth S. Norris Center for Natural History, where she led museum exhibit development, research projects, and educational initiatives to expand community engagement in natural sciences. With a degree in Environmental Studies focused on natural history and environmental and social justice, Jessica is passionate about connecting people with nature and fostering accessible science engagement.      Ciel Ramón-Cañas (they/them)  Administrative Assistant for Research & Collections and CNC Global Administrator Natural History Museum of Los Angeles County  Ciel joined the Research & Collections Department at the Natural History Museum of Los Angeles County in 2024, where they are assisting the R&C office and staff with a variety of tasks. Ciel has worked within the entertainment industry as a closed captions/subtitles editor for almost three years, where they oversaw a team of editors and ran quality control. They have also previously worked as an administrative assistant for the Honors Program at CSU Northridge, where they developed and refined their skills in grammar, clerical work, and product management. Ciel has a BA in Linguistics and is currently studying to get their Master’s in Speech Language Pathology.     Anabela Plos (she/her)  CNC Spanish Language Global Organizer Museo Argentino de Ciencias Naturales "Bernardino Rivadavia" MACN-CONICET  Dr. Anabela Plos has a PhD in Natural Sciences from the National University of La Plata, performs her duties at the "Bernardino Rivadavia" Argentine Museum of Natural Sciences as a member of the National Research Council Scientific and Technical (CONICET)  Since 2015, she has managed the Argentine node of the Global Biodiversity Information Facility (GBIF). Within the GBIF community, she served as Regional Representative of Latin American and Caribbean Nodes (2016-2021) and as a committee member of the Biodiversity Information for Development program for the Caribbean (BID), financed by the European Union, coordinated by GBIF. Anabela also coordinates and promotes activities related to open and participatory science, such as the City Nature Challenge, the Great Southern BioBlitz and various activities in the Wikimedia community in Argentina and the Latin American and Caribbean region.     Alison Young (she/her)  City Nature Challenge co-founder  Alison served as the Co-Director of the Center for Biodiversity and Community Science at the California Academy of Sciences, where she builds community and partnerships around nature and sharing knowledge about biodiversity, creates events and campaigns focused on documenting species, and brings this community-collected data to answer scientific questions and help inform decision-making. Alison also co-directed the Academy’s Thriving California strategic initiative, focused on scaling biodiversity science and education and collaborating with communities, other organizations, and the State to build a healthy, resilient future for people and nature in California. Alison’s background is in marine biology, she holds a Masters in Biology from Humboldt State University for research focused on the potential effects of climate change on California’s rocky intertidal communities, and a B.A. in Biology from Swarthmore College. When she’s not in the tidepools for work, she can often be found in the tidepools for fun – usually photographing nudibranchs, or in her local ceramics studio, happily bent over a pottery wheel, covered in clay.

About

NOTE  Any question or answer that refers to iNaturalist also applies to any of the iNaturalist network platforms: ArgentiNat, BioDiversity4All, iNaturalist.ca, iNaturalist.LU, iNaturalist.Se, iNaturalistAU, iNaturalistCL, iNaturalistCR, iNaturalistEc, iNaturalistFi, iNaturalistGR, iNaturalistGT, iNaturalistil, iNaturalistNZ, iNaturalistPa, iNaturalistTW, iNaturalistUK, naturalista.mx, NaturalistaCO, NaturalistaUY, Natusfera   Key Dates   Q: City Nature Challenge 2026 important dates:   Q: When can I start making observations that will count for the City Nature Challenge? When should I stop?   Q: Can I upload photos during the CNC that I took prior to the CNC?   Q: I took so many photos during the CNC that there’s no way I can get them all uploaded before the end of the day on April 27 – what should I do?   Making Observations   Q: Do I need to join my city’s project and add my observations to it for them to be included?   Q: How can I make sure my observations are in my city’s CNC project?   Q: What if my city isn’t within the boundary of the project? Can I still participate?   Q: What kinds of observations should I make during the CNC?   Q: What if I make an observation of something I know isn’t wild? Will it still count for the CNC?   Q: What if I don’t know what the organism is that I took a picture of? How do my observations get identified?   Q: Do I have to make observations using the app? What if I want to use a real camera?   Q: In order to participate, do I need to make observations and help identify others' observations?   Q: What about if I see something but didn’t get a photo of it – can I still make an observation?   Q: Can I use the Seek app to make observations?   Q: Tips for Taking Photos During the City Nature Challenge   iNaturalist   Q: Someone added an ID to my observation – should I agree with it? What if I don’t agree with it?   Q: How do observations in iNaturalist become Research Grade? Do my observations have to get to Research Grade to count for the CNC?   Q: Can I help identify what people found during the CNC? What if I’m not an expert in anything?

Take Part Yourself  Our list of participating cities and a link to our global project will be posted in February 2026.   Why participate?  There is nature all around us! Knowing what species are in our city and where they are helps us study and protect them, but the ONLY way to do that is by all of us – scientists, land managers, and the community – working together to find and document the nature in our area.  By participating in the City Nature Challenge, not only do you learn more about your local nature, but you can also make your city a better place – for you and other species!   Taking Part is Easy   It can be any WILD plant, animal, fungi, slime mold, or any other evidence of life found in your city. Take a picture or record the sound of what you find. Be sure to note the location of the critter or plant. Share your observations through iNaturalist or your city’s chosen platform. If it’s planted or taken care of by people it is not WILD. Mark it captive/cultivated!

Participate

Are you interested in being a local organizer for the 2026 City Nature Challenge (CNC)? Anyone can be a CNC organizer! We’ve had local organizers that are from all walks of life—from high school students and retired people to staff from nature centers, museums, non-profit organizations, and local government officials.   Organizer Responsibilities  Organizers are responsible for:   Attending virtual and asynchronous meetingsWorking with other organizers in your area (if multiple people express interest and/or your city has returning organizers)Setting up a project in iNaturalist or your city’s preferred platformPromoting the CNC in your community     Getting Started As a Local Organizer  The following information is provided as an example to prospective new organizers who may be considering joining in 2026.  Whether you are a NEW or RETURNING Organizer, here are some easy steps to get started:  New Organizers   1. to our email list to be notified about CNC 2026 (planning will begin in     October 2025). Please note that subscribing to the email list does not     commit you to organizing for the CNC, you can unsubscribe at any point. We     will share our official Commitment Form to fill out after the informational     and kickoff meetings (mandatory for all new organizers).  2. Attend one virtual New Organizer Informational Meeting or watch a recording     after sessions have concluded. Links to recordings will be sent to those who     have subscribed above.  3. Attend one virtual CNC Kickoff Meeting or watch a recording after meetings     have concluded.   4. Fill out the Commitment to Organize form (available in our Kickoff Meeting).  5. Register your city by filling out the City Information form in December     2025.  6. Attend all future meetings (see timeline below). All meetings are mandatory     for new organizers. Watching the recording counts as attending a meeting.  Returning Organizers   1. Attend one virtual Kickoff Meeting (mandatory for all returning organizers).     Watching the recording counts as attending a meeting. Check your email inbox     and spam folders for registration details.  2. Attend the December and March Asynchronous Meetings and the June Debrief     Meeting (mandatory for all returning organizers). The January and April     Planning Meetings are optional for returning organizers.   3. Fill out the Commitment to Organize form (link to form will be shared during     the November Kickoff meeting).  4. Register your city by filling out the City Information form (link to form     will be shared during the November Kickoff meeting).  *Note about virtual (a.k.a Zoom) meetings: We have organizers all over the globe. To accommodate all the different time zones, we hold each meeting at four different times (three in English and one will be in Spanish). Organizers only need to attend one of the three meetings. All meeting times are shown in UTC (Coordinated Universal Time), and will be recorded so you can catch up if you miss them.   City Nature Challenge 2026 Timeline  The following timeline is provided as an example to prospective new organizers who may be considering joining in 2026.  Subscribe to our to receive information about upcoming information and planning meetings.    October 2025  New Organizer Informational Meetings (on Zoom in English and Spanish). Mandatory attendance to one of four meetings for new organizers.CNC 2026 Kickoff Meetings (on Zoom in English and Spanish). Mandatory attendance to one of four meetings for new and returning organizers.  December 2025  Attend the December All Organizer Asynchronous Planning Meeting (on Google Docs). Attend iNaturalist How-to Training (on Zoom in English and Spanish). This training is for those organizers who are unfamiliar with making a City Nature Challenge project on iNaturalist or how to use the platform. Individual deadline for all organizers: fill out the CNC 2026 Commitment to Organize form to remain on our mailing list for 2026.  We’ll share the link to the Commitment to Organize form during the October kickoff meeting, and via an organizer email.Early Bird registration for cities: one person from each city should fill out the City Information form to receive perks associated with Early Bird registration. (The regular registration deadline will be in January for all cities to participate in CNC 2026). We’ll share the link to the City Information form during the October kickoff meeting, and via an organizer email.  January 2026  Attend Makeup iNaturalist How-to Training (on Zoom in English and Spanish). This training is for those organizers who are unfamiliar with making a City Nature Challenge project on iNaturalist or how to use the platform. Note this is the EXACT SAME training as the December training.Attend the January Organizer Planning Meetings (on Zoom in English and Spanish). Mandatory for new organizers. Optional for returning organizers.City deadline: make your city’s project on iNaturalist or your city’s chosen platform.  February 2026  Official CNC 2026 City List posted on CNC website by end of month.  March 2026  Attend the March ALL Organizer Asynchronous Planning Meeting (on Google Docs March 3-19).  April 2026  Attend the April Organizer Planning Meetings (on Zoom in English and Spanish). Mandatory for new organizers. Optional for returning organizers.CNC observation period: April 24 - 27CNC uploading & identification period (April 28 - May 3)  May 2026  Results announced (May 4)Dates for CNC 2027 announcedFill out All Organizer Debrief Survey  June 2026  All Organizer Debrief Meeting (on Zoom in English only).   Organizer FAQ   How will we stay in touch?   How can I access the resources and information I will need as an organizer?   How many cities can I organize as a CNC local organizer?   What if I live in a rural area? / What counts as a “city?”   How can I tell if my city is already a CNC participant?   Do I have to use iNaturalist?  We’re always happy to answer more questions. Contact us .

CNC Local Organizer Information

2024 Infographic

The City Nature Challenge is a collaboration-meets-friendly-competition to see what can be accomplished when we all work toward a common goal of observing nature in urban settings. The big three results, highlighted here, are for the total number of observations, species, and people who participated, all around the world. Below, you will find the contributions of each city to these total numbers.   The displayed number of species is higher than the actual count. The correct number will be displayed with our final results.  Loading...

Live Results

Research Papers  BioScience The city nature challenge: A global citizen science phenomenon contributing to biodiversity knowledge and informing local government practices  PeerJ Life & Environment A citizen science approach to evaluating US cities for biotic homogenization  Biodiversity A case study from the City Nature Challenge 2018: international comparison of participants’ responses to citizen science in action  UCL Discovery Evaluating public engagement with biological recording events - Case study of City Nature Challenge 2018  Biological Conservation COVID-19 pandemic drives changes in participation in citizen science project “City Nature Challenge” in Tokyo  ArXiv iNaturalist citizen science community during City Nature Challenge: new computational approach for analysis of user activity    Press and Media  Loading Docs Here the Wild Things Are City Projects: Auckland/Tāmaki Makaurau, Ōtautahi/Christchurch, Taranaki, Te Upoko o te ika/Wellington The San Diego Union-Tribune San Diego Natural History Museum plans biodiversity blitz City Project of San Diego Atlántida Ecocampus aúna a colectivos con objeto de conocer su fórmula para participar en la conservación de la biodiversidad City Project Bahia de Cadiz El Guadarramista ¿Te apuntas al City Nature Challenge 2018? City Project Madrid, Barcelona, Sevilla, Bahia de Cadiz EFE: Verde Cuatro ciudades españolas en el biomaratón para la observación de la naturaleza City Project Madrid La Vanguardia Biomaratón busca impulsar observación de naturaleza en 4 ciudades españolas City Project Madrid, Barcelona, Sevilla, Bahia de Cadiz South China Morning Post Conservation in Hong Kong: citizen scientists enlisted to record and safeguard city’s amazing biodiversity City Project Hong Kong am New York Forest Hills’ QueensWay teaches biodiversity, human impact to high school students City Project New York City Utah Public Radio Nature is Calling: Satisfy Your Curiosity And Contribute To Scientific Research Using iNaturalist City Project Wasatch Front (Salt Lake City) Voice of America Youngsters Help Scientists Study Nature in 16 US Cities City Project Los Angeles / All Cities Marin Independent Journal City Nature Challenge a fun way to become a naturalist City Project San Francisco / Los Angeles KCET Why is Citizen Science Important? City Project Los Angeles / San Francisco Los Angeles Times L.A. takes on San Francisco in the first City Nature Challenge City Project Los Angeles / San Francisco

Press & Publications

2025 Infographic

Observations Species People   Participating Cities    The results below are sorted alphabetically by city, rather than by the highest number of observations. To sort by observations, species, or people, click on the column heading.

Current Results

Want to find out more about the City Nature Challenge? Fill out the form below to contact the event’s co-organizers.  Name: Email: Subject Message: Submit

Contact Us

&nbsp;<h2>Planning for City Nature Challenge 2026 has begun!&nbsp;</h2>If you're interested in becoming a local organizer, visit the <a href="https://www.citynaturechallenge.org/organizers">Organizer page</a> for information, and <a href="https://docs.google.com/forms/d/e/1FAIpQLSe8CXSfsDMXEAH5eEDRSw8KXTV0AEAwpeM14Y5Sqrg52oYEIQ/viewform">subscribe</a> to our email list to learn about upcoming meetings.

Started in 2016 as a competition between Los Angeles and San Francisco, the City Nature Challenge (CNC) has grown into an international event, motivating people around the world to find and document wildlife in their own cities. Run by the Community Science teams at the California Academy of Sciences and the Natural History Museum of Los Angeles County (NHM), the CNC 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.


Make observations of wildlife in your area for the City Nature Challenge.

Participants

For information about organizing for 2026, click below.

Cities

Join the City Nature Challenge!

Taking pictures of wild plants and animals.


April 24 – April 27, 2026

April 28 – May 10, 2026

It can be any plant, animal, or any evidence of life found in your city.

Find Wildlife

Take a picture of what you find. Be sure to note the location of the critter or plant.

Take picture

Share your observations through iNaturalist or your city's chosen platform.

Share!

Taking part is easy

Your participation makes an impact on understanding biodiversity and coexisting with nature. See the scientific research that has been made possible by City Nature Challenge participants like you!

City Nature Challenge Science

2025 Totals

Cities around the world collaborate to share observations of nature in the 2026 City Nature Challenge.
