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