Over 66,000 community scientists from 482 cities around the world document more than 2,570 rare, endangered, or threatened species in a four-day community science effort
Los Angeles, CA (May 8, 2023) — The City Nature Challenge (CNC) results are in! More than 66,000 people across 46 countries and six continents documented more than 1.87 million wildlife observations for the 8th annual community science initiative. More than 57,227 species were observed, with the Mallard Duck coming in as the most popular around the world and the Western Fence lizard as the most common in Los Angeles County.
The global event called on current and aspiring community scientists, nature and science fans, and people of all ages and backgrounds to observe and submit pictures of wild plants, animals, and fungi from April 28 to May 1. Participants submitted pictures of wild plants and animals using the free mobile app, iNaturalist. The competition underscores the power of community science to track real-time changes in our planet’s biodiversity.
After co-founding and organizing the first-ever City Nature Challenge in 2016 as a competition between the Los Angeles and San Francisco metro areas, the Natural History Museum of Los Angeles County (NHM) and the California Academy of Sciences expanded the initiative to 482 cities this year. This year’s 1.87 million observations included sightings of more than 2,570 rare, endangered, or threatened species. The Challenge engaged more than 66,000 observers around the world, including 1,671 in Los Angeles County alone.
Local support for the City Nature Challenge was generously provided by Boeing and the Los Angeles Department of Water and Power.
Los Angeles County by the Numbers
Species: 2,646 (including 72 rare/endangered/threatened species)
485 people created their iNaturalist account since the beginning of April and collectively made 3,190 observations and recorded 294 species
Average number of observations per person: 15.29
Los Angeles County Highlights
Slender-horned Spineflower (Dodecahema leptoceras), endemic to California and listed as federally endangered – observed by plantsoflacounty
Palos Verdes Blue (Glaucopsyche lygdamus ssp. palosverdesensis), critically imperiled in the U.S. – observed by asedillos
Coast Patchnose Snake (Salvadora hexalepis ssp. virgultea), imperiled in California – observed by amandacg
By-the-wind Sailor (Velella velella), floating on a bed of kelp – observed by sara_medina
Joshua Tree (Yucca brevifolia), in front of snow-capped mountains – observed by helenabowman
Least Bell’s Vireo (Vireo bellii ssp. pusillus) sound recording, endangered in the U.S. – observed by neontetraploid
California Common Scorpion (Paruroctonus silvestrii), fluorescing under a black light flashlight – observed by lhiggins
Water Fern (Azolla filiculoides), imperiled in the U.S. – observed by nshrodes
Sailfin Catfishes (Pterygoplichthys sp.), invasive in parts of the U.S. due to aquarium dumping and abundant in the Sepulveda Basin, these particular fish had probably moved away from the main pond when water levels were high due to our many atmospheric rivers and then got trapped and died as water levels dropped – observed by hsmiths
Fire Poppy (Papaver californicum), known to grow in recently burned areas – observed by lglevanik
Great Horned Owl (Bubo virginianus), on a cliff nest with older chicks – observed by fowlivia
Mojave Woodyaster (Xylorhiza tortifolia), can we call this observation of an endemic California flower with a crab spider and two flies a “four-fer?” – observed by jonathan27
World by the numbers
Species: 57,227+ (including more than 2,570 rare/endangered/threatened species)
Most-observed species globally: Mallard duck (Anas platyrhynchos)
Highlights from around the U.S. and the world include an inquisitive yellow-crowned night heron in Texas, a giant electric ray with albinism near Mexico’s Socorro Island, an Indo-Pacific humpback dolphin off the coast Hong Kong, a pair of red fox pups in England, a short-tailed weasel after a successful hunt in Utah, Asian weaver ants dismembering a queen from a rival colony in Thailand, a carefree southern sea otter in California’s Monterey Bay, a pointy, peach-colored sea slug in New Zealand, a coast patchnose snake in Orange County, a critically endangered buchu plant in South Africa, and a Pacific horned frog in Ecuador.
The current landscape of urban biodiversity is poorly understood. As global human populations grow increasingly concentrated in cities, documenting urban biodiversity—and our impact on it—is a crucial part of understanding our shared future. Large pools of data, including those built by iNaturalist and natural history museums, aid in scientific research and help land managers make informed conservation decisions for humans to sustainably coexist with regional plant and animal life.
In 2022, the Challenge tallied more than 1.69 million observations, including over 2,244 rare, endangered, or threatened species; engaged more than 67,000 observers; and recorded over 50,100 species worldwide.