Naturalist Born Thrillers

In the rooftop greenhouse of the Houston Museum of Natural Science, John Watts is a happy man. The 36-year-old entomologist picks up the caterpillar of a zebra butterfly, so named for the distinctive yellow stripes that mark its black wings, turns it over and gently squeezes its rear end. A strong, musky, odor results, a dry, peculiar smell that seems a combination of bitter leaves and insect blood. Not many people would find it pleasant; most people, actually, would find it repugnant. But Watts thinks it's wonderful.

There's much about butterflies that Watts thinks is wonderful. He likes how their caterpillars "hang Js," a term derived from the shape they make when they spin a button of silk and attach themselves to a branch or a leaf or (in the case of the Museum greenhouse) the tops of their cages. He adores how they wiggle out of their skins and prepare to enter into the chrysalis stage, when all of the caterpillar's internal organs except the brain and central nerve cord melt into a protoplasmic soup and are transformed into the angular body and bright wings of a butterfly. He likes the requirements the different caterpillars that metamorphose into different butterflies have: that the monarchs must eat milkweed, and the peacocks must eat lemon verbena, and the julias will only lay their eggs on a certain kind of passionflower vine and how eating only those plants gives them a bitter taste to birds. He likes the way the caterpillars of the giant swallowtail resemble fresh bird droppings. He likes the names that butterfly watchers have given to their favored object -- red postman, lacewing, white peacock, pale cracker, clipper, gold rim, cattleheart, rice paper, southern belle, magnificent owl -- and he likes it that butterflies do not bite, scratch or sting. That last little fact means that butterflies, unlike some other insects, are people friendly. Which is something that John Watts particularly likes, because that means Watts can have an unusual job for an entomologist, one that's more involved with keeping insects alive than making them dead.

That simple truth about entomology, that what an entomologist is fascinated by is often what he kills, is reflected in a Far Side cartoon pinned on a bulletin board near where Watts is working. (Far Side creator Gary Larson, incidentally, studied entomology at Texas A&M). The cartoon shows two collectors in pith helmets in the field with butterfly nets, and one who has made a capture says to the other, "An excellent specimen, symbol of beauty, innocence and fragile life ... hand me the jar of ether."

At the Cockrell Butterfly Center, though, Watts doesn't deal much with ether. He deals more with birthing. Not that death is something he ignores. Since their average life span is only two weeks, the Cockrell butterflies are constantly dying. So as they walk the Butterfly Center's paths, Watts and other workers keep an eye peeled for corpses. Butterflies that are beaten up, crushed by the heels of visitors or eaten by ants are deposited in a designated plastic wastebasket, then sterilized in an autoclave to prevent disease. But the dead butterflies whose wings and bodies are in decent shape go into a large plastic box and are sold to the gift shop, which resells them in wax paper envelopes to people who want to mount them for display. And that is yet another reason that John Watts likes butterflies, and a big reason why the Houston Museum of Natural Science is so enamored of them. Butterflies make money. The Cockrell Butterfly Center is part of a growing business in nature's showoffs. Opened in 1994 and named for Houston oil man and museum board leader Ernie Cockrell, the center generates wads of cash for the Museum of Natural Science. Close to 400,000 visitors a year pass through the center; with ticket prices of $3.50 for adults and $2 for a child, it doesn't take much math to understand a part of the center's non-scientific appeal. Like the IMAX movie theater, the Butterfly Center makes more money than it spends, which helps support other aspects of the science museum. The realization of this is one reason why, across the nation, the building of butterfly centers has become a trend. Denver opened one recently, Durham, North Carolina, has one in the works and St. Louis is thinking about one. In New Orleans, plans for an insect zoo are well under way.

Of the nation's nine most prominent butterfly gardens, the Cockrell is the only one that's multilevel, allowing visitors to see butterflies high in the forest canopy as well as at ground level. Following a short introductory film, visitors enter into a concrete cave that holds a pool into which a 40-foot waterfall cascades. Only a few butterflies hang out at the entrance -- just as there's not much there for the visitor to see, there's not much there for them, either -- but as the visitor ascends a curving stairway to enter the main level, he encounters a huge artificial tree wrapped with strangler vines. Through the grace of tape recordings and stereo speakers, monkeys howl and tropical birds sing. Misting machines spray a fine, ground-level fog. The temperature is kept at a constant near-80 degrees.