LOS ANGELES — Scores of second-grade students scrambled through the Discovery Science Center in Santa Ana, huddling inside simulators to feel the shaking of an earthquake, building mini-ski jumps to learn about speed and shaping wet sand into riverbanks to observe erosion. The hands-on experiences allowed them to test theories they had only read about in textbooks or heard about from teachers.

"A couple of kids have asked me, 'Is this really science?' " said Kathleen Carney, a teacher at Deerfield Elementary School in Irvine.

At a time of shrinking budgets and increased emphasis on standardized testing, such class visits to science centers, museums and zoos are increasingly rare, according to educators and site operators.

Across the nation, 60 percent of teachers surveyed reported decreased funding for field trips in recent years. In California, that could get worse as school districts grapple with Gov. Arnold Schwarzenegger's proposed budget, which would cut about $4.8 billion in education funding this year and next.

Field trip coordinators, school principals and teachers attribute the decline in student visitors to increased classroom hours devoted to the high-stakes English and math testing required by the federal No Child Left Behind Act, as well as budget cuts.

"Everything is geared toward that testing," said Linda Kahn, a vice president at the Bowers Museum of Cultural Art in Santa Ana. "And money. Money is a huge issue for each and every school."

Between the 2005-06 and the 2006-07 school years, student visits to Bowers' "First Californians" exhibit about mission life dropped nearly 50 percent to 880 students, she said.

FEWER STUDENTS VISIT

The Natural History Museum of Los Angeles County has seen a sharp decline every year since 2004-05, when 241,075 students visited. In 2007, the number dropped to 172,764, which museum officials attribute to increasingly crowded school days and concerns about money.

"It makes me terribly sad," said Carl Selkin, the museum's vice president for education, who grew up in New York. "I still remember when I was a kid in school how exciting field trips were. I just grew to love museums, the Metropolitan Museum of Art, also the American Museum of Natural History. Those are images I still carry with me."

Because it does not charge admission, the National Zoo in Washington does not keep track of student visitors. But teachers routinely speak about the obstacles in taking trips to the 163-acre zoo.

"We've heard from many teachers the same sorts of problems — it's cost-prohibitive, they have to test to the standards so there's not time for field trips, there are not enough chaperones. We hear that all the time," said Elise Bernardoni, an education specialist with Friends of the National Zoo. "A lot of schools just flat out can't pay $300 for a bus, and frankly, there's nothing we can do about that."

Schools that continue to take trips increasingly rely on parental fundraisers and grants.

TRIPS A PRIORITY

Myra Ruedal and two other fifth-grade teachers at Emperor Elementary in San Gabriel received a grant to take their students on field trips last year — a priority, not a luxury, the teacher said.

"Because of the low economic (level) of our students, they don't get to go anywhere," Ruedal said. "We're taking them beyond the borders of Temple City and San Gabriel. They get to see there's life outside of this community."

As part of a spending freeze, the Riverside Unified School District in January ordered its schools to re-evaluate the necessity of any field trip not funded by donations.

In Moreno Valley, one of Superintendent Rowena Lagrosa's first tasks when she took over in 2006 was to scale back field trips. Some were not educational, such as end-of-the-year excursions to amusement parks, she said. Others no longer fit in schools' crammed schedules, she said.

The district takes 40 percent to 60 percent fewer trips than it once did.

"Time is our most valuable asset," Lagrosa said. "Our school years are just not long enough, and our school days are just not long enough. We want to ensure that when parents send students to school, it's for instruction."

Some museums and other institutions are responding by aligning their programs with state and federal standards.

After the 1998 opening of the Discovery Science Center, 84,781 students visited on field trips during its first fiscal year. But the numbers began to dip, and within three years it had lost 23,000 field trip visitors annually. So center officials redesigned the exhibits to emphasize their link to California science standards, which dictate what concepts students must be taught at each grade level. The museum also focused on a specific grade level each month.

"We upgraded the field trip experience," said Leslie Perovich, vice president of the center. "We use large-scale exhibits to teach science concepts tied into the grade level."

It worked. The numbers began climbing, and in the fiscal year that ended in June, 83,949 students visited the center.

Kahn said Bowers held a workshop for elementary school teachers in April to show how the museum could tie into their lesson plans, and expects to hold more in the fall.