We are currently experiencing problems with our participating cities page and are working to resolve the problem.   In the meantime, if your city uses the iNaturalist platform, you can check their participation on our . (A few cities use other platforms, including Amsterdam, Barcelona, Copenhagen, Eindhoven, Guimarães, Salzburg, Sevilla, Sheffield, and Vorarlberg, which are all 2026 participants.)  If you do not find your city, we invite you to join our to participate in this year's City Nature Challenge.

Participating Cities

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. (Wild means that it wasn’t put there, and is not being taken care of by people.) 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

City registration is now closed for 2026.   Read on to learn about organizing your community in 2027.  Planning for City Nature Challenge 2026 is underway. The following information is provided as an example to prospective new organizers who may be considering joining in 2027.  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  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 2027 (planning will begin in Fall     2026). 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 by January 2027.  6. Attend one virtual Project Management Training or watch a recording after     meetings have concluded.  7. 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, March Project     Management Training, 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 Fall Kickoff meeting).  4. Register your city by filling out the City Information form (link to form     will be shared during the Fall 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 2027 Timeline  The following timeline is provided as an example to prospective new organizers who may be considering joining in 2027.  Subscribe to our to receive information about upcoming information and planning meetings.    September/October 2026  New Organizer Informational Meetings (on Zoom in English and Spanish). Mandatory attendance to one of four meetings for new organizers.CNC 2027 Kickoff Meetings (on Zoom in English and Spanish). Mandatory attendance to one of four meetings for new and returning organizers.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.   December 2026  Attend the December All Organizer Asynchronous Planning Meeting (on Google Docs). Individual deadline for all organizers: fill out the CNC 2027 Commitment to Organize form to remain on our mailing list for 2027.  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 2027). We’ll share the link to the City Information form during the October kickoff meeting, and via an organizer email.  January 2027  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.  February 2027  Official CNC 2027 City List posted on CNC website by end of month.  March 2027  Attend the March ALL Organizer Asynchronous Planning Meeting (on Google Docs).Attend the March Project Management Training (on Zoom in English and Spanish). Mandatory for all organizers.City deadline: make your city’s project on iNaturalist or your city’s chosen platform.  April 2027  Attend the April Organizer Planning Meetings (on Zoom in English and Spanish). Mandatory for new organizers. Optional for returning organizers.CNC observation period: TBDCNC uploading & identification period: TBD  May 2027  Results announced: TBDDates for CNC 2028 announcedFill out All Organizer Debrief Survey  June 2027  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

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. It's an annual four-day global bioblitz at the end of April, where cities collaborate to see what can be accomplished when we all work toward a common goal.   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            Rebecca Johnson (she/her)  Director, Center for Biodiversity and Community Science and City Nature Challenge co-founder California Academy of Sciences (iNaturalist username @rebeccafay)  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)  Associate Manager, Community Science and CNC Managing global organizers Natural History Museums of Los Angeles County (iNaturalist username @amyjaecker-jones)  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.        Jessica Carver (She/Her)  Associate Manager, Center for Biodiversity and Community Science and City Nature Challenge Managing global organizers California Academy of Sciences (iNaturalist username @jesscarvs9)  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 (iNaturalist username @cielramon)  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.        Liz Amador (she/her/ella)  Program Manager, Community Science and CNC Global Organizer Natural History Museums of Los Angeles County (iNaturalist username @lamador2)  Liz joined the Community Science Department at the Natural History Museum of Los Angeles County in 2026. Her primary roles include supporting CNC along with other community science programs. Liz is a Chicana and California Native from Garden Grove. Her research has taken her up north to study the central coastline in Monterey Bay and to Maine where she studied flowering across the U.S. She is interested in the integration of community science and long-term monitoring methods within coastal and terrestrial ecosystems. In her free time she enjoys crafts, hikes, and free diving.        Laura Schare (she/her)  Temporary Program Manager, Community Science Program and City Nature Challenge Supporting global organizers (iNaturalist username: scubabruin) Natural History Museum of Los Angeles County  Laura also currently volunteers with the National Park Service in the Santa Monica Mountains National Recreation Area at the King Gillette Ranch Visitor Center and other NPS events throughout the year. From 2023 - 2025, Laura dedicated time researching and writing a bi-weekly newsletter, It’s All Connected, covering topics related to nature, environment, sustainability, climate change, and more. She is a certified California Naturalist and Catalina Naturalist, serves as an iNaturalist Ambassador, and a former volunteer with the Heal the Bay education team.       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.        Ram Dayal Vaishnav (he/him)  CNC India Regional Organizer Head of Citizen Science & Engagement, The Naturalist School  Ram Dayal Vaishnav is an Environmental Researcher and a seasoned professional in the conservation space, and a well-known advocate for citizen science, including as a TEDx speaker. As the Head of Citizen Engagement at The Naturalist School, he leads citizen science programs and has been instrumental in expanding the City Nature Challenge to all corners of India and Asia. On an international scale, Ram Dayal serves as a Working Group Secretary for Citizen Science Global Partnership, where he collaborates with various UN agencies. He also holds the role of Education Director at CitizenScience.Asia, where he founded the Asia Nature Challenge. He is also a PhD Scholar at TransDisciplinary University, studying Citizen Science for Biodiversity Documentation. His comprehensive efforts to advance citizen science for species Red List assessments and other biodiversity documentation include past work with organizations like IUCN, iNaturalist, National Biodiversity Authority and WWF-India, along with his involvement in initiatives like Tiger Beetle Watch.        Lila Higgins (they/them)  City Nature Challenge co-founder  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.     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

The City Nature Challenge is no longer a competition. Instead, we celebrate collaboration and what can be accomplished when we all work toward a common goal of observing nature in urban settings. For this reason, results are sorted alphabetically. If you wish to sort by the number of species, observations, observers, or identifiers, click on the column heading. In order to reduce the strain on pulling results from iNaturalist, individual project pages will be updated hourly.  Results are sorted alphabetically. If you wish to sort by the number of species, observations, observers, or identifiers, click on the column heading.   For the best experience using this page:  Mobile users: scroll to the right to see all columns. Use the drop-down arrow to expand results for each city. (As this is a new feature, the drop-down results may not be viewable for cities using platforms other than iNaturalist.   What does Research Grade mean?  Research grade observations are those that have reached a quality and identification level sufficient to be used in scientific research. They include photo or sound evidence of an organism, an accurate date and time, and are not of a captive animal or cultivated plant. Not all observations will achieve research grade status due to factors such as photo quality or because identification is only possible with a physical specimen.   Back to

Understanding City Nature Challenge 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

Past Results

2024 Infographic

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

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?

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

City Nature Challenge 2026 Virtual Events  SENA Centro de Gestión Industrial Coordinación plan de trabajo | Reto Naturalista Urbano 2026: Sabana de Bogotá Bogotá, Colombia Spanish Online City of Boise Parks & Recreation Ada County City Nature Challenge iNaturalist Training Ada County, Idaho, USA English Online Jardín Botánico de Bogotá | Forest in Motion Reto Naturalista en los Bosques Urbanos: Monitoreo con iNaturalist Sabana de Bogotá, Colombia Spanish Online South Dakota Discovery Center MacroBlitz Onboarding - Observing Aquatic MacroInvertebrates for the CNC North & South America English Online Macaulay Honors College City Nature Challenge: NYC - Getting Started on iNaturalist Webinar NYC, but applicable to other locations English Online San Diego State University Upping Your Game With Better iNaturalist Observations and Identifications for the City Nature Challenge Southern California; Global English Online Santa Monica Mountains Fund/ National Park Service City Nature Challenge: iNaturalist in NPS Wildlife Research Zoom English Online Macaulay Honors College City Nature Challenge: NYC - Virtual ID Party! New York City, but all are welcome English Online Oana Marin, ROOTS Grădini Urbane Identification Party | City Nature Challenge: București Bucharest, Ilfov and Global Project Romanian Online Natural History Museum of Los Angeles County ID Party | CNC: Los Angeles County Los Angeles County, but all are welcome English Online

Events

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 collaborate 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

City Organizers

Join the City Nature Challenge!

Taking pictures and recording sounds of WILD plants and animals. 

(Wild means that it wasn’t put there, and is not being taken care of by people.)


April 30 – May 3, 2027

Uploading observations and identifying what was found.

Dates To Be Decided

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

(Wild means that it wasn’t put there, and is not being taken care of by people.)

Find Wildlife

Take a picture or record a sound 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

2026 Totals

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