- The third-annual City Nature Challenge takes place this weekend, April 27-30, 2018, giving nature lovers in cities around the globe a chance to compete against other cities to see who can make the most observations and find the most species of local plants and animals.
- Residents and visitors from nearly 70 cities will use their smartphones and the iNaturalist app to share photos of their findings over the 4-day period; experts will verify the identifications in early May.
- Organizers hope the event will connect more people to their local urban biodiversity and uncover threatened and invasive species in new locations, to assist local resource managers.
This coming weekend, nature lovers from cities around the globe will have a chance to test their species identification skills in a global competition. The third-annual City Nature Challenge takes place April 27-30, 2018.
Participants from over 65 cities on five continents will compete to see who can make the most observations of local plants and animals, find the most species, and engage the most people in the outdoor photo exploration.
The Challenge uses the iNaturalist app, which is managed by the California Academy of Sciences and National Geographic. It started two years ago as a nature-finding competition between the cities of San Francisco and Los Angeles. Despite its growth and international scope, organizers Alison Young and Rebecca Johnson of the California Academy of Sciences told Mongabay-Wildtech that their aim for the 2018 Challenge remains to connect people to their local nature and to each other and have fun while they’re at it.
![Having fun collecting and sharing data on the nature around us - identifying that plant, bird, or bug you see every day can make it more meaningful.](https://imgs.mongabay.com/wp-content/uploads/sites/20/2018/04/25172140/Yerba_Buena_Bioblitz-5588_small.jpg)
A second aim is to collect urban biodiversity data, during the annual Challenge and throughout the year, that can be valuable for science or management.
As one example, Young and Johnson wrote in an email, the many Challenge participants may document the presence of an invasive species that can trigger a rapid response from resource managers to keep the species from spreading.
“Many of our City Nature Challenge organizers work in partnership with their local land managers and policymakers (e.g., parks departments, city governments) to hold events in locations where more species data are needed and to make sure these groups know about the urban biodiversity data being collected and how to access it,” Young and Johnson said.
![A team member in a recent "bioblitz" on Yerba Buena Island in San Francisco Bay sharpens his focus to capture a new plant.](https://imgs.mongabay.com/wp-content/uploads/sites/20/2018/04/25172216/Yerba_Buena_Bioblitz-5629_small.jpg)
How to join the City Nature Challenge
Curious about what critters share your neighborhood or local park? You can join the event in one of these cities. You can select your target city from the list to learn where you can search for species and what institution is organizing the contribution in your area.
The organizers also created a kit for learning how to use the iNaturalist app, bringing classes of kids of different age groups outside to participate, and incorporating the event into a curriculum.
To participate, you need to find some wild animals and plants, take photos of what you and your friends discover, and upload them with some information on when and where you saw each critter to the iNaturalist app.
![A team member in the recent Yerba Buena Island "bioblitz" captures a worm along the shore.](https://imgs.mongabay.com/wp-content/uploads/sites/20/2018/04/25172232/Yerba_Buena_Bioblitz-5669_small.jpg)
You can download the app from the AppStore or Google Play, which allows you to see photos taken by other people. To upload your own observations, you must create an account and sign into the app or visit the iNaturalist.org website. You can then upload photos and/or descriptions of plants and animals you see, with a suggested identification if you have a good idea of what you saw.
The iNaturalist online network encourages people to share information about nature. More than 685,000 nature enthusiasts have registered on the app to record nearly 9 million observations of 159,000 species.
Others in the community, who are rated by their expertise, help to identify the critter or plant in your photo. Acknowledged experts and experienced naturalists will volunteer their time May 1-3 to identify the thousands of photos resulting from the Challenge, so on May 4th, you can learn what you and others in your city found during the four photo collection days.
![](https://imgs.mongabay.com/wp-content/uploads/sites/20/2018/04/25172102/orchid-with-label_SP.jpg)
The iNaturalist team has also begun applying computer vision to provide faster taxonomic identifications for user-submitted photos. Currently, computer vision suggestions represent only about 5% of identifications made on the iNaturalist site this year, co-director Scott Loarie told Mongabay-Wildtech. Computer pattern recognition algorithms need reference data—ideally, multiple images from various angles or seasons—of each species to compare to any new photo they encounter.
“The computer vision suggestions work best in places where we have a lot of data,” Loarie said. “So in U.S. cities, they should be very helpful. But the 2018 City Nature Challenge includes some cities in countries where there’s not a lot of iNaturalist activity so far, like Brazil and India. While this means the computer vision suggestions won’t be too helpful in these places this year, it also means that every observation from these cities will be a valuable contribution for training and improving the model.”
![](https://imgs.mongabay.com/wp-content/uploads/sites/20/2018/04/25172122/white-tailed-deer-in-urban-DC-park_SP.jpg)
A growing effort
After the two-city competition of 2016, the 2017 Challenge logged roughly 125,000 observations. The roughly 4,400 participants last year found more than 8,600 species during the 4-day event. This year, the event directors expect the greater number of participants and locations to uncover many more species.
“Last year during the City Nature Challenge, we documented over 300 rare/endangered/threatened species in the 16 participating U.S. cities,” Young and Johnson said. “Knowing where these species occur is vital for conservation, especially in metro areas where they’re often threatened by habitat loss. This year, with 69 cities around the globe taking part in the City Nature Challenge, many of which do not have extensive species occurrence data sets, we’re bound to find species in locations where they were not known to occur, rare species, and other surprises.”
![](https://imgs.mongabay.com/wp-content/uploads/sites/20/2018/04/25172042/Yerba_Buena_Bioblitz-5731_small.jpg)
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