Started in 2016 as a competition between SanFrancisco and Los Angeles, the City Nature
Challenge (CNC) has grown into an internationalevent, motivating people around the world to find
and document wildlife in their cities. Run by theCitizen/Community Science teams at the
California Academy of Sciences and the NaturalHistory Museum of Los Angeles, the CNC is an
annual four-day bioblitz-style competition at theend of April, where cities are in a friendly contestagainst each other to see which one can gatherthe most observations of nature, find the most
species, and engage the most people in the event.In 2019 more than 150 cities participated, withover 35,000 people making almost one millionobservations of nature in the four days of the
challenge. The 2020 City Nature Challenge (April24-27) is gearing up to be the biggest one yet, with
over 250 cities signed up in more than 40countries.
"One of the best global experiences of people participating in a commongoal around the whole world!"
- City Nature Challenge organizer from Barcelona
About the City Nature Challenge
Goals of theCity Nature Challenge
Connect people in urban/metroareas to their local natureConnect people to each other: buildcommunity in person & onlinearound local natureCollect urban biodiversity dataavailable to use for science,management, and conservationGrow volunteer biodiversitydocumentation globallyHave fun through some friendlycompetition!
California Academy of Sciences
California Academy of Sciences
Growth of the City Nature Challenge
Cities
Countries
Observations
Species
Observers
2016
2
1
19,800
2,500
1,000
2017
16
1
125,000
8,600
4,000
2018
68
17
441,000
18,000
17,000
2019
159
28
963,000
31,000
32,000
2020
250+
40+
For more information, visit www.citynaturechallenge.org
"The City Nature Challenge unites theworld with biodiversity engagement in a
manner that is meaningful, simple and fun.It gives communities the opportunity to
explore their surroundings and contributeto the monitoring of biodiversity with anease that wouldn't have been deemed
possible years ago. The world needs moreevents like this."
- City Nature Challenge organizer fromHong Kong
Impact of the City NatureChallenge
Since 2017, the CNC has been thelargest annual observation recording
event in iNaturalist, and resets the"baseline" of observations coming into
iNaturalist after each CNC. Not onlydoes the CNC inspire new people to
observe nature during the event itself, ithighlights the value of this work and
inspires some participants to becomebiodiversity observers year-round.
CNC 2019
CNC 2018
CNC 2017
Smriti Safaya
Tan Kai Ren