Connecting with Nature Through Your Phone

During this year’s international City Nature Challenge, tens of thousands of people across the world went outside to take photos, document, and identify animal and plant species in their communities.

1 minute read

June 27, 2023, 5:00 AM PDT

By Clement Lau


Close-up of hands holding mobile phone up to a plant to take a photo

K.Decha / Adobe Stock

The City Nature Challenge is an international effort for people to find and document plants and wildlife in cities across the globe. It is 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. The first City Nature Challenge in 2016 was an eight-day competition between Los Angeles and San Francisco, engaging residents and visitors in documenting nature to better understand urban biodiversity. 

As reported by Bella Isaacs-Thomas, over 66,000 participants worldwide contributed to a total of almost two million observations of plants, animals, fungi and any other living things between April 28 and May 1, 2023. Observers documented more than 57,000 species, including over 2,570 species that are rare, threatened, or endangered. 

During the four-day challenge, many participants snapped photos on their smartphones and uploaded them to iNaturalist, an app designed to document and identify wildlife. The city of La Paz in Bolivia took the gold for most participants this year. Those observers also made both the highest number of observations and spotted the most species. Over 3,000 people in that city spotted 5,344 species and made more than 126,000 observations collectively.

Wednesday, May 10, 2023 in PBS News Hour

portrait of professional woman

I love the variety of courses, many practical, and all richly illustrated. They have inspired many ideas that I've applied in practice, and in my own teaching. Mary G., Urban Planner

I love the variety of courses, many practical, and all richly illustrated. They have inspired many ideas that I've applied in practice, and in my own teaching.

Mary G., Urban Planner

Use Code 25for25 at checkout for 25% off an annual plan!

Interior of Place Versailles mall in Montreal, Canada.

Montreal Mall to Become 6,000 Housing Units

Place Versailles will be transformed into a mixed-use complex over the next 25 years.

May 22, 2025 - CBC

Logo for Planetizen Federal Action Tracker with black and white image of U.S. Capitol with water ripple overlay.

Planetizen Federal Action Tracker

A weekly monitor of how Trump’s orders and actions are impacting planners and planning in America.

June 4, 2025 - Diana Ionescu

White and yellow DART light rail train in Dallas, Texas with brick building in background.

DARTSpace Platform Streamlines Dallas TOD Application Process

The Dallas transit agency hopes a shorter permitting timeline will boost transit-oriented development around rail stations.

May 28, 2025 - Mass Transit

Line of multi-colored big rig trucks drivign down highway with other traffic including a yellow school bus.

Study: 4% of Truckers Lack a Valid Commercial License

Over 56% of inspected trucks had other violations.

June 4 - FreightWaves

Pedestrian holding visual impairment cane pressing crosswalk button.

Chicago Judge Orders Thousands of Accessible Ped Signals

Only 3% of the city's crossing signals are currently accessible to blind pedestrians.

June 4 - DRA Legal

People on bike wearing helmets stopped at intersection waiting for passing cars in Philadelphia, Pennsylvania.

Philadelphia Swaps Car Lanes for Bikeways in Unanimous Vote

The project will transform one of the handful of streets responsible for 80% of the city’s major crashes.

June 4 - Philly Voice

Urban Design for Planners 1: Software Tools

This six-course series explores essential urban design concepts using open source software and equips planners with the tools they need to participate fully in the urban design process.

Planning for Universal Design

Learn the tools for implementing Universal Design in planning regulations.