In 16 U.S. cities, citizen scientists, including schoolchildren, spent a few days this month documenting plant and animal species and helping scientists understand their regions' diversity and the challenges many species face.
The City Nature Challenge, held April 14-18, is a competition that was started last year by the Natural History Museum of Los Angeles County and San Francisco's California Academy of Sciences. This year, it involved institutions across the United States. The challenge is to see which city can document the most species; results are to be announced Saturday, which is Earth Day.
"Last year, it was San Francisco against Los Angeles," said Lila Higgins, manager of citizen science at the Natural History Museum of Los Angeles County. "This year, it's L.A. versus San Francisco and New York and Chicago and Seattle and many, many other cities."
The young citizen scientists took photos and recorded observations on their cellphones, uploading the data through a phone app called iNaturalist.
Frank Az, 9, of Esperanza Elementary School in Los Angeles said he loves observing nature, "finding different species of birds and insects." He was outside the museum with binoculars and a cellphone camera, along with other students.
His friend, Andrea Garcia, was excited as she described finding "two mourning doves in their nest" as well as "ants, bees and a house finch."
The children worked with some adult scientists who monitor species in this region, including Greg Pauly, a specialist on amphibians and reptiles at the Natural History Museum. Pauly said that Los Angeles is one of the world's 35 top biodiversity hot spots, but that the sprawling urban complex also faces "a large threat to that biodiversity."
The children documented their sightings of insects, flowers and birds alongside their teachers. It is something they do regularly at school. Principal Brad Rumble of Esperanza Elementary said the migration of one bird species had captured the children's interest.
"Every year, we do a contest to predict when will the yellow-rumped warbler first arrive on campus," he said. The students vote, and those who correctly guess the date when the tiny visitor appears get a trip to the Natural History Museum.
"That little bird," said Rumble, "brings up so many wonderings about geography and range and weather, and why does it like this tree? These questions form in students' minds, and they're off and running."
The children are learning many lessons, said museum President Lori Bettison-Varga.
"We are part of this environment, and they are part of this environment — the plants, the animals, the critters that live here," she said, "so it's really helping us to understand how to increase the health of our environment."
And this annual competition, she said, gets people of all ages involved in science.