My work as a wildlife writer often takes me to the Amazon and the African grasslands. I tell friends back home they don't really need to travel to see wildlife: the insects and other weird little creatures in our own backyards are at least as interesting as any elephant. But I can tell they don't much believe me. So I was curious to see what would turn up one weekend last summer at a BioBlitz in Hartford, Connecticut, a nearby city not generally known for unusual life-forms.

A BioBlitz is an event in which dozens of scientists fan out across some unlikely habitat, hell-bent on recording every species they can find, dead or alive, in a 24-hour period. The scientists launching themselves into Hartford's 695-acre Keney Park at 3 p.m. that Friday were armed with spotting scopes, sweep nets, pit traps, scalpels and fish stunners. They were prepared to dance like butterflies, sing like chickadees or do almost anything else this scavenger hunt required. One collector was seeking someone to donate bait for his dung beetle trap. Another was erecting what looked like a device for extracting sunbeams from cucumbers.

It consisted of a big galvanized-steel funnel mounted on a tripod, and it was actually meant to extract animals from soil samples. With a coffee can, a slight, white-bearded man named Carl Rettenmeyer cut out a disk of grassy soil and leaf litter "about the size of a quarter-pounder, with lettuce." This sample would sit overnight on a screen in mid-funnel, with an electric light overhead to make things uncomfortable, and a killing jar below to collect whatever came creeping out.

 By Saturday afternoon, the "quarter-pounder" of lawn alone would yield 23 separate species, and 89 individual animals, including mites, thrips and an awful lot of springtails, "little bitty things smaller than the head of a pin." The springtails run around with their tails tucked under their abdomens, spring-loaded so that, in case of danger, they can execute a "we-outta-here" backflip, six inches into the air. It is a skill two-legged city-dwellers can only envy.

"The area of the sample is 11.044639 square inches," Rettenmeyer said. "Now multiply that by..." Then he came up with his best estimate: that there are 50 million individuals in just the top inch of soil in an ordinary acre here, and 35 billion animals in Keney Park — nearly six for every man, woman and child on earth.

"People are hearing that word ‘biodiversity,' but they think it's in the rain forest," said Ellen Censky, director of the Connecticut State Museum of Natural History at the University of Connecticut. "The BioBlitz is a way of letting them know there's a lot of biodiversity right here."

It's also a lark, the closest most scientists will ever get to a varsity sport. Censky is a wry, enterprising sort who once proposed a museum exhibit that consisted of a dead elephant in a room full of flesh-eating dermestid beetles. It didn't happen (some nitpicky problem with ventilation), but it showed a certain flair for ecological entertainment.

BioBlitzes have become regular events around the country since the first one took place four years ago in Washington, D.C. Censky's team was hoping to top the record of 1,905 species found in a 1998 biodiversity survey around Walden Pond, outside Boston. She had assembled her roster with a coach's eye for covering all positions, from fish-squeezers to bat-grabbers. She was piling on entomologists with a knack for quickly identifying obscure insects. She had specialty teams, too, including an algae expert and a parasitologist.

Out in a wooded section of the park, a herpetologist named Hank Gruner had just caught a garter snake, which promptly regurgitated a wood frog. Two species for the price of one. Gruner started flipping over old furniture someone had dumped. "Herpetologists love debris," he said, snatching up a writhing, glossy-purplish creature in his palm, his 25th red-backed salamander in the past hour. "By biomass, they actually outweigh the birds, and they're equal to the small mammals," he said, letting it go again. "All that with no lungs. They breathe by diffusion through their skin and through their throat."

 Elsewhere in this depressed neighborhood in Hartford's north end, the algae expert found a green alga closely related to the one from which all land plants on earth appear to have evolved. Coleochaete grows on cattails and rushes, she said, and it's probably 500 million years old. Keney Park was also discovered to be home to freshwater sponges, as well as to symbiotic algae, which live on the sponges and spoon-feed them the by-products of photosynthesis. The larvae of two species of spongilla fly feed, in turn, on the sponges, sucking up a soup of algae and cellular fluids. One species moves away from the sponge just about the time of year the other arrives to make its home there, like vacationers time-sharing a condo.

At 10 p.m. two biologists had rigged 30-foot-long mist nets across a shallow stream, and bats in the thrall of the hunt promptly got their leaflike wings tangled in the netting. One of the bat experts delicately extricated them, protecting himself with — what else? — a batting glove. He tucked one big brown bat into a cardboard toilet-paper roll, and the roostlike snugness calmed the creature down long enough for it to be weighed in at 13 grams before it fluttered free.

Around midnight out in the woods, a black light set up by the entomologists cast a faint purple glow among the dark tree trunks. Nearby, a host of light-dazzled wolf spiders, water bugs, beetles and slug moths assembled on a reflective bedsheet. The BioBlitz crew set to work, and the air was filled with the sound of killing jars opening and the smell of ethyl alcohol. A beetle expert got on his knees and sucked up specimens, pfft-pfft, into an aspirator jar. Someone told a story about a scientist who didn't realize he was working with an inefficient aspirator. "He wound up with 70 insects in his sinus cavity. An entire ecosystem. Alive. They published an article about it." The beetle guy went pfft-pfft, undaunted.

Things quieted down till just before dawn. Then the birders came out and stood around, heads cocked, hands in pockets, at odd angles to one another, listening. "It sounds like a worm-eating warbler," said Frank Gallo, who clearly wasn't expecting to find the species here. "Before I write this down I want to hear it better." He bashed in through the undergrowth and called out pish-pish-pish, engaging the bird in a short dialogue. "Pine warbler," he pronounced, satisfied now. Next Gallo did an admirable imitation of a chickadee, bursting out in a high nasal deee-deee-deee. Other species flock around when they hear a chickadee call, he explained.

Good sightings began to pile up as the morning grew long: a bald eagle, a 12-inch-long pileated woodpecker, a coyote. At a table back at headquarters, a parasitologist picking through the guts of a grasshopper came up with two parasites practicing syzygy, which means that they were mating head to tail. One scientist triumphantly picked a tick off someone's leg, and when a cat-mauled short-tailed shrew showed up just outside the door, the maggots got counted, too.

As the witching hour drew near, lepidopterist Dave Wagner had 295 species of moths and butterflies. "I wish I could get 5 more," he lamented. "How much time do I have? Twenty minutes?" He started to pick through the insect refuse piles where others had been working. "Twenty-seven ants!" someone yelled.

"No more insects," said the woman who was keeping the insect tally, 60 seconds from the 3 p.m. deadline. "No more nothin'."

"I'm up to 305," said Wagner.

"That's it, Dave. We're not counting any more."

"...306...307."

It was the lepidopteran equivalent of a long-distance runner in his final unstoppable sprint.

"Wait! I haven't given you my dung beetles yet," another entomologist yelled, fondly cradling his entire collection in a jar lid.

A small crowd had gathered outside to hear the final count for this BioBlitz. It came to 1,369 species. Less than the record at Walden Pond. "Wait'll next year," someone muttered. (Censky's crew will try again on June 2 in Meriden, Connecticut. The Massachusetts survey will take place June 9-11.) "I know some of you won't be happy to hear this," the parasitologist was telling the crowd, "but we were delighted to find 35 species of parasites. So congratulations, Hartford." And from the enthusiasm in her voice, you could tell that the weird little creatures in our own backyards, even down to the lowliest flatworm, were as glorious to her as a pride of lions.

By Richard Conniff