Biological diversity does not come easily near the intersection of Olympic Boulevard and Hoover Street.
The neighborhood just west of downtown is one of the most crowded in Los Angeles County, with 25,352 people per square mile. It's chock-full of buildings and has lots of pavement, little landscaping and many economically disadvantaged families.
In that setting, Leo Politi Elementary School wanted only to make a dreary corner of campus more inviting to its 817 students. Workers ripped out 5,000 square feet of concrete and Bermuda grass three years ago and planted native flora.
What happened next was unforeseen. It was remarkable.
The plants attracted insects, which attracted birds, which attracted students, who, fascinated by the nature unfolding before them, learned so much that their test scores in science rose sixfold.
In the words of Leo Politi's delighted principal, Brad Rumble, "We've gone from the basement to the penthouse in science test scores."
As Rumble stood in the garden recently, 10-year-old Jacky Guevera fixed her eyes on an orb spider spinning a web near a pair of bushtits building a nest in the limbs of a crape myrtle tree.
"At our school, flycatchers drink the water in the vernal pool," said Jacky, who dreams of becoming an ornithologist. "Scrub jays hang out in the oaks. The snapdragon's red flowers attract Anna's and Allen's hummingbirds."
"I can identify each of these birds when I see them," she added confidently as she sketched images of the garden's wildlife.
Three years ago, the school's standardized test scores in science for fifth-graders showed that 9% were proficient and none were advanced. Last spring, 53% of fifth-graders tested as proficient or advanced.
Leo Politi's garden grows where a towering apartment complex once stood. The structure was torn down in 1991 to make room for the school, named in honor of Leo Politi, a children's book author and illustrator who earned the prestigious Caldecott Medal in 1950 for "The Song of the Swallows," his book about the swallows at Mission San Juan Capistrano.
In partnership with Los Angeles Audubon, Leo Politi in 2008 became one of the first elementary schools in the city to apply for and win "schoolyard habitat" and partner's grants from the U.S. Fish and Wildlife Service.
With $18,000 from the agency, and volunteer assistance from environmental students at Dorsey High School, Leo Politi removed the concrete and grass from the forlorn corner of campus. Dorsey students wielded rakes and shovels and helped select and plant bushes, flowers and trees, including six live oaks that now shade a slope Rumble calls "our oak highlands."
Nature responded quickly to the clumps of rye grass, owl's clover and waist-high thickets of white sage and wildflowers: California poppies, California wild roses, tidytips and island snapdragons.
"First to arrive were insects -- lady beetles, butterflies and dragonflies -- almost as if they were lying in wait," Rumble said. "They were followed by birds that feed on them."
At that point, students were hooked. "Questions about why some birds flocked to one plant and not another led to discussions about soil composition and water cycles, weather patterns and seasons, avian migration and the tilt of the Earth in its orbit around the sun," Rumble said.
Now, the children are studying the dynamics governing the behavior of birds and the ecological systems that support them. They are also compiling an online illustrated survey of every species documented in their urban bird sanctuary, calling it "A Field Guide to the Flora and Fauna of Leo Politi Elementary School."
To education experts, the concept of project-based learning is nothing new. "If students are actively engaged in a real-world project -- whether it be working on a car engine, designing a dress or cultivating a garden -- it's going to turbo-charge classroom curriculum," said Guilbert Hentschke, a professor of education at USC's Rossier School of Education.
"Most educators intuitively or professionally understand this," Hentschke added. "And most would love to do it, but they don't always have the time, money, staff or space."
Lourdes Ortiz, a director of instruction for the Los Angeles Unified School District, said Leo Politi's experience is one reason administrators are encouraging schools across the district to develop projects unique to their needs.
"They could be gardens or something else," Ortiz said. "More and more students are also going to be learning from projects linking them to life outside of class."
Fish and Wildlife dispenses about $60,000 a year in its Pacific Southwest Region to help teachers and students create wildlife habitats on school grounds, said Carolyn Kolstad, the agency's regional schoolyard habitat coordinator. About 50 schools in the area have been helped over the last four years.
The benefits are much greater than pure science, said Robert Jeffers, lead arts and humanities teacher at Dorsey and Los Angeles County teacher of the year in 2010.
At Leo Politi, the garden has "instilled a profound sense of responsibility and awareness of nature," Jeffers said. "Now these kids can tell the difference between a crow and a raven, which requires cognitive skills of understanding subtleties and nuances important throughout life."
Jeffers' point is evident in Mary Ellen Rhieman's twice-weekly Audubon class, where second- and third-graders learn about the distinguishing marks of bird species, flight patterns and the use of avian field guides.
On a recent weekday, talk turned to the use of metaphors and adjectives -- "formidable," "ungainly," "exquisite" -- in recent news articles about an albatross with a 7-foot wingspan found wandering in Los Angeles, and a bald eagle living outside the Orange County Zoo's bald eagle exhibit.
What's all that got to do with science test scores?
Everything, her students say. They see how the skills they use to describe downy woodpeckers and eagles in poetry or essays -- observation, concentration and attention to detail -- also help them in daily life.
"What is a pattern?" asked Rhieman, a retired principal teaching under a special contract funded by private donations.
"Something that repeats," several students said in unison.
"Like the roller-coaster flight of a lesser goldfinch," added another.
The garden and Rhieman's class are springboards for older students who receive weekly after-school workshop lessons in science illustration taught by Stacey Vigallon, director of interpretation for L.A. Audubon.
That five-week class concluded with students learning to mix up to 10 shades of green with colored pencils. Among them was Jesus Olvera, 11, who labored over a rendering of a burrowing owl. No sooner did he complete a meticulous sketch of the bird's eyes than he erased it and started over.
After four successive attempts at perfection, Vigallon intervened.
"At some point, Jesus, you have to commit -- so finish those eyes and move on," she advised with a smile. "Sometimes meeting a deadline is more important than achieving absolute perfection."
Since the garden was planted, students have documented and illustrated more than 25 species of birds, including the meadowlark that dropped in around Thanksgiving, an ash-throated flycatcher that visits each autumn and a white-crowned sparrow spotted last Sunday.
Rumble, who sits on L.A. Audubon's board of directors, recalled the day when he urged kids over the public-address system to step outside and "look up at the more than 60 turkey vultures circling overhead."
"Luckily, the vultures' arrival coincided with recess," Rumble said.
As he spoke, Jerry Molgado, 10, watched a small black-and-white bird on the branch of a Western redbud tree.
"It's a black phoebe," Jerry said. "It likes to fly off and swoop in the air, then hurry back to the same branch. It's chasing insects."