Join NHMLAC in the City Nature Challenge This Weekend!

City Nature Challenge — one of the world’s largest community science events — returns for its 10th year of connecting people through local nature and their communities this weekend.

From participating in organized biodiversity surveys (such as the Elephant Hill Habitat Survey on Saturday, April 26) to recording the wildlife in their own neighborhood, the City Nature Challenge encourages community scientists of all levels to explore their local environment—all while contributing to biodiversity science and conservation and using free mobile apps like iNaturalist. Kicking off April 25 at 12:01 am local time, the Challenge runs through April 28, 11:59 pm, followed by the online community’s identification of photographed species April 29 – May 4 and results announced on May 5.

After launching the City Nature Challenge in 2016 with just 1,000 observers across a pair of California cities, the Challenge — hosted by the Natural History Museums of Los Angeles County (NHMLAC) and San Francisco’s California Academy of Sciences (CAS) — broke numerous records in 2024, with more than 83,500 community scientists around the world amassing over 2.4 million observations from 690 cities in 51 countries. Since its inception, City Nature Challenge has collected over 7.13 million urban biodiversity observations of 94,000+ species and engaged over 364,000 people.

For both budding and veteran community scientists, participation is easy. Photos of wild plants, animals, or fungi taken during the Challenge can be uploaded to iNaturalist, where an online community of naturalists confirms species identifications.

WHERE: Roughly 700 cities globally

WHO: More than 80,000 community scientists

COST: Free

LINKS: citynaturechallenge.org or nhm.org/cnc