"I sit in a machan, a tree platform, alone, perched over a kill, waiting for the tiger to return...all is still, completely still. Until I feel, and then hear, footfalls crunching leaves. The sound is steady, deliberate, and direct to the kill. I hardly breathe, knowing the slightest movement will elicit a deep, terrifying growl before the tiger retreats into the night."

So goes the dream of John Seidensticker, curator of mammals at the National Zoological Park, chairman of the Save the Tiger Fund Council and a great friend of the tiger ever since he pioneered the use of radiotelemetry in tracking these spectacular beasts in the wild.

Thanks to him and others, the National Zoo now has a machan of its own, where even children can get a close-up view of some of the tigers and lions that live there. Or they can also walk the 278-foot wooden elevated trail called "Tiger Tracks," to work the interactive information devices designed with children in mind. Both the machan and "Tiger Tracks" are part of the new "Great Cats" exhibit, which also features educational facilities, natural history specimens and lookouts for kids.

"Tiger Tracks" is a trip. You walk along the hillside, nicely landscaped with pampas grass and bamboo, overlooking one of Washington's more unexpected rural scenes, complete with a sparkling creek, and you are invited to read cunningly placed placards containing educational tips. Question on wooden book cover: How powerful is a tiger's bite? You open the cover: It can bite through a two-by-four. How strong is a tiger? It can bring down a 2,000-pound animal. There is all the information here that you could ask for.

There is an exhibit of bronze tiger paws, one taken from a plaster cast made of a tiger at the Zoo, an operation I would like to have seen, I think. You can fit your spread hand nicely inside one. There is also a bronze tiger tongue that you can rub. It is as rough as sandpaper. And here is a scale on which you can compare your weight with a tiger's 500 pounds. That is a fairly large male. The female weighs from about one-half to two-thirds as much as her male counterpart.

Following the tracks (of a tiger mother and her cub) along the trail, you learn about the risks of being a tiger in the first place: about half the cubs die in their first year. Also, they need to eat — a lot. For instance: Taj, the 14-year-old white tiger, a mix of Siberian and Bengal subspecies, bolts down 65 pounds of horse meat and oxtails every week. But then, he weighs 340 pounds and has to keep his strength up. He can expect to live another five or six years at the zoo, though in the jungle he would be running out of time at 14. Rokan, a Sumatran male, the smallest of the five surviving subspecies, is considered overweight at 338 pounds, so he gets only 30 pounds of meat a week. Kerinci, a 13-year-old tigress from Sumatra, where she was found as an orphaned cub, weighs 178 pounds and gets 62 pounds a week (she has a terrific metabolism and tends not to gain weight). Her daughter, Soy, 5, is bigger than she is. At 186 pounds, Soy eats 32 pounds of meat a week.

These animals are something special. Although any individual lion can outweigh any individual tiger (we'll get to the lions a bit later), tigers in general are considered the largest carnivores on land.

Carnivores eat only meat, of course, which means they eat other mammals that live on plants. Which means they need a huge amount of space, because their habitat has to include not only plenty of water and vegetation cover but also enough territory to support the deer and pigs that they eat and the plants that the deer and pigs eat in turn.

That's why there aren't and never have been all that many tigers around.

Today there are only about 6,000 wild tigers on the planet, mostly in India and Southeast Asia. It sounds like a lot, but even after 30 years of efforts by conservationists the tiger is endangered.

"The early '90s were dark days for tigers," says John Seidensticker. An ecologist, he worked for the Smithsonian in Nepal, then for the World Wildlife Fund in Indonesia and Bangladesh, and eventually returned to work at the Zoo in 1983. "They're endangered for two basic reasons, one short-term and one long-term. The short-term problem is poaching," explains Seidensticker. "Tiger bones are a valued element in traditional Chinese medicine. Bone is used in wine or in pill form, often for rheumatism, just as we take aspirin. Tiger bone wine is great for what ails grandpa."

Efforts are under way to promote acceptable substitutes, says Seidensticker, but getting people to use them may prove challenging. "It's not like bear bile, which is very big in East Asian medicine and is used to treat such life-threatening diseases as stomach cancer. And about the aphrodisiac effect of tiger parts: that's myth."

The long-term problem for tigers is the steady fragmentation and degradation of habitat that occurs when forests are burned or cut down and when prey — such as the deer and pigs that are also hunted by man — begin to vanish.

Meanwhile, at the Zoo, the four tigers and three lions enjoy 30,000 square feet of space shaded by oaks and Himalayan pines (whose flanks are padded with extra bark for protection against claws), three grassy terraces with dens, and a moat of clear water. A path or walkway runs around the habitat, and it is there, or at the machan, that you can watch these lovely creatures living out their lives.

In places glass windows have been installed in the walkway wall for the use of wheelchair visitors (who have access to the machan and to "Tiger Tracks" as well). Along the way are special alcoves, including the Kid's Stop that provides glass-fronted lookouts for children.

The Predator's Alcove, a mini-museum, features fossils and examines the ecology of tigers, lions and other predators. It also displays a bronze casting of a Tyrannosaurus rex skull, to remind visitors who was the greatest terrestrial predator of all time. Now life-size tiger paws are all very well, but this skull is an arresting sight. It sports six-inch teeth and jaws that extend four feet in length. But then the T. rex could grow 20 feet tall and 40 feet long, every inch of it hungering to gobble you alive.

Unlike lions, a tiger hunts alone, roaming up to 20 miles a night in search of the 30 or 40 pounds of meat it must eat during the course of a week. It may take as many as 20 hunts to bring in a kill that provides enough food. Like many hunters, the tiger is territorial. Where the prey is plentiful, say in Nepal, a female may need about 8 square miles, but on the far eastern coast of Russia she can require up to 200 square miles. Male territories are even larger but overlap with those of females.

Every cat lover has an overpowering need to pat a tiger or lion and scratch it behind its furry ears. This is not a good idea. The keepers know. The keepers realize that to the tigers they are a potential dinner. At the Zoo one does not go into the enclosure even with the nicest tiger.

Keepers must go through a series of safety gates (sign: "Please Don't Feed Fingers to Animals") to reach a tiger's indoor enclosure. There, while the big cat is outside, they check out any untouched food, any abnormality in the feces. They get to know cats and the clues they leave. Some cats are light eaters anyway. Some are stoic about illness and have to be watched for small signs of pain. Between the enclosure and the yard are two steel doors with dead bolts that set off a runway. Keepers move the cats along this runway with the aid of sliding doors on pulleys, color-coded for safety. Thus, doors leading into the runway are blue with blue handles, and doors inside the runway, used when more than one tiger is being run through, are yellow. In the evenings tigers are brought back inside.

This is the fun part of the keeper's job. The other part includes mucking out the enclosures and defrosting and weighing the ground meat for dinner. Rokan gets about four pounds a day. He is fed indoors through a food chute. Just in case someone gets the idea that it might be interesting to feed a tiger by hand, a metal feed pan has been hung on the wall by the food preparation area. The pan is torn half to shreds by a tiger's long, sharp canines.

On Sundays the tigers get oxtails, something like bones for dogs — except they're two feet long.

Both lions and tigers sleep most of the day — 20 hours in fact — and the rest of the time the big cats prowl their territory, marking the boundaries with scent. They do have large 30-pound balls to play with, and on a hot day Rokan (but not the lions) will bat one into the moat and swim after it.

"Great Cats" has been a long time aborning. Seidensticker told me the idea arose in the early '80s as conservationists realized just how endangered tigers were. The plan was to replace the fading posters and run-down graphics in the Lion/Tiger House (built in 1976) with materials that would better educate the public about tigers and other big cats.

"We thought we could do it by 1986, the building's tenth anniversary," says Seidensticker. "Boy, was I wrong; I had no idea how much effort it would take. It was not until the Save the Tiger Fund came along, backed by the National Fish and Wildlife Foundation and Exxon Corporation, that things began to take shape. "This is a zoo," he added, "and it should be fun, but we need to convey the educational message, too — serious information about the importance of saving the tiger in the wild."

Part of the tiger conservation program is breeding. Soy, the 5-year-old, or Kerinci, her mother, is to be bred with Rokan to produce, with luck, more Sumatran tigers. Kerinci's previous litters consisted of two cubs each. (Gestation is about 106 days, by the way.) On my way out I visited the lions, who live on the other side of the hill. I saw Thandi, a 263-pound lioness, 14 years old, stretched out on the grassy slope, dead to the world. Nearby, but paying no attention to her, sat the twin brothers, Tsavo and Tana, 10 years old on November 15. They each weigh around 485 pounds. Tsavo is supposed to have a shorter mane than Tana, and a scar on his nose, but to me they looked identical.

There they lounged, on the top terrace, side by side — I read that male lions are very companionable — with their front paws hanging over the grassy edge while they stared in perfect unison at all these people who were being exhibited to them on the other side of the moat.

I was going to whisper "Kitty, kitty, kitty!" but they would have been mortified.

By Michael Kernan