Nature’s Way of Mating Whoopee

The sweet young voice puts it this way: “Oh look, the monkeys are playing wheelbarrow.”

Monkey love, in one form or another, is a hazard of the job for Kent Yamaguchi, curator of education at the Santa Ana Zoo.

What do you tell two dozen inquisitive kindergartners gaping at two monkeys en flagrante?

“I just said, ‘Uh-huh, let’s move on,’ ” Yamaguchi says.

Still, on Saturday many of nature’s secrets will be revealed when the Santa Ana Zoo hosts its fourth annual Valentine’s Day Sex Tour for adults. The popular tour explains the to and fro of animal love--from sloth sex to monkey contraceptives.

The tour has grown every year, Yamaguchi says. “On the second year, we had calls from Canada to Australia. It was sort of like, ‘What are these crack-balls from California up to now?’ ”

Credit for the zoo sex tour concept goes to Jane Tollini, a penguin keeper at the San Francisco Zoo.

Tollini conceived the sex tour nine years ago while watching her penguins’ monthlong courtship ritual that culminates in bizarre sex.

“It doesn’t look like fun sex,” Tollini says. “It’s kind of awkward-looking. They’re both shaped like little torpedoes. There’s a lot of bill clacking and wing waving.”

Tollini started checking out the sex in other parts of the zoo.

“I feel like a voyeur, but the more I watched, the more interesting it got,” she says. “You name it, they do it. They just do it a little differently.”

The female praying mantis stimulates her mate by nibbling on his brain. “By the time they’re done, he’s almost completely eaten,” Tollini says. “It’s fun for her, but I doubt it is for him.”

Turtles “have some of the noisiest sex in the world,” she says, “they grunt and groan, and their shells clack together.”

Orangutans can do it hanging upside down. Lions can climax as many as 50 times in 24 hours. And male rhinos sometimes knock their mates into the air during rough foreplay.

But it’s millipedes that win Tollini’s Valentine’s Day award as the most romantic critters. “They do it belly to belly. He kind of embraces her with all 250 of his arms and legs. It’s kind of sweet.”

Tollini is gaining a national reputation for her steamy, irreverent sex tour--which she pitched to her bosses in 1987 by playing Johnny Mathis tunes for the courting penguins.

The Mathis tunes are now a tradition.

Next year, the San Francisco zoo hopes to lure Mathis himself to the zoo to perform for the penguins--and the ever-growing crowds of curious adults who fork over $35 for an afternoon of sex chat, champagne and chocolate-covered strawberries.

Although it lacks violent rhino foreplay, the Santa Ana Zoo does have champagne and chocolate and its share of intriguing tour twists.

There’s a hot romance in the aviary between two female double-striped thick-knees. The South American birds have banished their male counterpart to the bushes.

“They are living an ‘alternative lifestyle,’ ” Yamaguchi says. They’ve tried separating the couple, but nothing works. The male lives a monastic existence in the bushes while the females hang out by the pond on one leg, occasionally nesting on unfertilized eggs.

Zoo employees still hope one of the females will sneak off into the bushes for a midnight tryst with the banished male to make some thick-knee babies.

Each year, Santa Ana Zoo curator Connie Sweet highlights one animal with a surprising or intriguing reproductive feature. This year: the secrets of snake sex.

The tour costs $25. Reservations are required: (714) 953-8555. Participants must be 18 or older.

A final warning: Don’t buy into a tour in Santa Ana or San Francisco expecting to see an animal version of “Caligula.”

“We had one woman call and say, ‘I can’t believe you make those animals do it in front of people,’ ” Yamaguchi says, laughing.

Truth is, animals do it when they please or, in many cases, only when zoo curators allow it. Rarely do they get caught in the act on these sex tours.

“Today, we caught two walking sticks going at it in front of God and everyone,” Tollini says. “Insects love sex. They have a lot of sex.”

But, as with most things in nature, there’s a catch: “They’re at the bottom of the food chain so they have to reproduce a lot,” Tollini says. “They have to have a lot of sex.”