BLAME IT on the postman. He delivered a travel brochure with the Pandas Ling-Ling and Hsing-Hsing hugging in the double "O," promising a 21-day wild life safari in the South Pacific. The Friends of the National Zoo, called "FONZ," were offering a "group tour" to Australia and New Zealand.

The tour would include stopovers in the Fiji Islands and Tahiti, and visits to zoos and sanctuaries. In Australia the group would see the marsupials (an Australian monopoly with only the opossum of America to compete) - koalas, kangaroos, wallabies and wombats; the fairy penguins parading; the platypus, the strange creature with a duck bill, webbed feet and fur coat, who lays eggs, yet suckles its young; the kookaburra, dingo and the black swan.

We also would visit New Zealand, the islands with no native mammals except two species of bats; no snakes, hoofed animals, primates, woodpeckers or vultures, yet home of the flightless but fleet-footed kiwi bird and the kauri, tallest hardwood trees in the world.

A group tour? We had traveled many years - over four continents, through 29 countries - but always as rugged individualists.

This package meant spending 21 days with the same people, doing the same sight-seeing, all-inclusive, Washington-to-Washington. But we couldn't resist the chance to travel "down under." So we signed on.

We found zoos down under struggling with the same problems faced by our National Zoo - space, funds, renovation and modernization, education for schools and public, research, propagation and preservation.

By buying such a specialized group package, the Friends of the National Zoo had the advantages of economy air fare, pre-selected hotels. American breakfasts and known expenses for fees, tips and transportation of people and baggage to and from airports and hotels. Guided tours in various cities were based on the group's mutual interest in zoos, sanctuaries, gardens and museums.

The interest peg that brings together a group is a good start. Zoos are one man's ticket; cathedrals or golf another's Personalities? Everyone has met the leaper and the laggard, the fearful and the cheerful, the talker and the listener. You get to know them all on a group tour.

The experience began with a meeting at the National Zoo of the tour group, 24 men and women and a FONZ official. Names were exchanged over crackers, cheese and wine.

Later we flew across the United States to begin our adventure. A widening sunrise marked the arrival at Nandi, Fiji. One of our tour members with a suspected heart attack was taken by ambulance to the hospital while the rest of us, sobered, took a bumpy bus ride to the hotel, where the tour was assigned to "villages" - separate buildings scattered in zigzag pattern along the beach.

As we walked past wet shrubs of plumeria, hibiscus and brilliant helaconia, tiny green finches skipped into the air as they were disturbed from their ground feeding. We looked up as the plane flew off on another leg of the South Pacific flight. We felt left behind. It had been 25 hours and a missing day because of the dateline since departure from Washington, D.C.

Even at the leisurely, pace of the happy and beautiful Fijians, the four days sped by as we swam, cruised to Castaway Island and toured the island of vitu-Levu sharing a mini-bus with a group of Japanese tourists.It was a time to note contrasts between luxurious tourist hotels and the simple villages where Fijians continue old ways of communal cooking in thatched-roof huts and washing clothes in the river. Modern times had arrived in Nandi with a new supermarket.

We didn't know it then but the most vivid sunset of the trip was the last night in the Fijis. A happy group assembled for early departure aboard Air Pacific. The group now called each other by name; some shared stories of the four days. We had been assured that our tour member left behind in the hospital was doing well.

We flew to Australia, the world's smallest continent and largest island, with Brisbane, capital of the state of Queensland, the first stop for our journey along the western coast.

The visit to a pineapple factory was an augur of things to come. All the meals in Australia would include the golden fruit, sliced or wedged.

Tropical Brisbane, build on seven hills, straddles the Brisbane River, upstream from Moreton Bay and sprawls in three directions, surpassed only by Los Angeles, Tokyo and Moscow in area.

The group had its first glimpse of the koala in a visit to the Lone Pine Sanctuary, and learned that the Koala is not a "bear" at all but a marsupial. The koala eats only eucalyptus (gum) leaves and never drinks water, and it turns out the little fellow can eat only about 15 species of the more than 600 eucalyptus species in Australia. Thus he cannot survive without his own brand of leaves. He never adapts to another variety.

Zoologist David Fleay has spent 26 years on his 65-acre Fauna Reserve in his personal effort at conservation of the wildlife of Australia, including emus, masked owls, bower birds, koalas, wombats, cassowary and wallabies. THere are 50 species of kangaroos in Australia.

For 30 years another dedicated man, Alex Griffiths, had hand-fed the beautiful rainbow lorkieets. When he no longer could manage, the Currumbin Bird Sanctuary became part of the National Trust. Its domain resembles a miniature race course with a paddock where peafowl strut. Twice a day thousands of red and green lorikeets fly from the bush to be hand-fed.

On the Ansett flight to Sydney, some of the irritations of packaged travel surfaced - demands for window seats, the latest magazines, boarding with too much hand luggage. The same thing had happened on a Washington-to-London flight, but this time we knew the offenders - they were part of our group.

The plane followed the coast with fiords and tiny islands, over scrub, gullies and gorges, over the land-locked harbor of Sydney where the Opera House hung on the water as if a child had stacked fortune cookies on a blue mat.

Sydney, capital of New South Wales, is an exciting city of theater, shopping and sightseeing - "sister to San Francisco," the driver proudly claimed - with a 45-year-old subway system recently extended to the suburbs. Its entrances are marked with fountains and plazas.

We noted the grilled ironwork balconies, manufactured from ship ballast by convicts, the parliament house paid for by rum; a yacht club in every bay, and some gold-and some white-sand beaches.

At Sydney the group visited its first zoo. Taronga Zoo Park, set along the harbor, with displays of 5,000 animals in the 70-acres of bushland and gardens. The guides, all volunteers, are particularly knowledgeable on Australi's wildlife, since each year the volunteer staff works with 60,000 children attending half-day classes.

De. Peter Crowcroft is in charge of both Taronga and the new Western Plains, an open range wildlife park - both state zoos. There is no national Australian zoo. Crowcroft, a native of New South Wales spent 10 years with the Brookfield, Ill., Zoo, returning to Taronga in 1975.

He said that zoos once functioned as entertainment with people coming to see animals. Today the animals act as ambassadors for wild relatives. He continued, "As with all zoos, we don't have sufficient money, and every 10 years it i necessary to re-build." He told us that the work of zoos is more than just displaying the well-known animals, it is preserving and propagating the little-known and threatened species. He said that all giraffes in Australia are descended from an original pair in Taronga. Almost as a prayer, he added, "I'd love some pandas."

Taronga has the largest collection of Australian birds - 2,000 of 30 varieties - exhibited in landscaped aviaries. The 1972 rain forest aviary has different levels for more than 100 birds, with treetops for the lorikeets and honey-eaters, pools for the kingfishers and a forest floor for the beautiful bower birds.

Dr. Crowcroft said that many birds have become extinct in the last 100 years and others are threatened. Therefore all zoos cooperate in trying to breed and exchange them. Since it is illegal to import birds, Dr. Crowcroft bemoans that the only flamingos Taronga has are all ancient spinsters and when they go, there goes the flamingo display.

Animals in the Night is one of the largest nocturnal houses where day is night in an underground building, recreating the world of the night feeding wildlife. The burramys, though to be extinct, was found in 1966 on Mt. Kosciusko at 7,000 feet, and Taronga is the first zoo to exhibit the rare marsupial.

After the Burramys, we visited the platypus, the duck-billed monotreme first added to the zoo in 1969. The aquatic platypus is found only in Australian and Tasmania. The echidna, the only other monotreme in modern animal life, but terrestial, is also displayed. Although the echidna has continued to lay its single egg, no young has survived in the zoo. Taronga is the first and only zoo to hold a pair of numbats, the rare species of marsupial that exists on a diet of termites.

It was time to fly south - "to get cooler" - as an Australian said. We flew over Canberra to Melbourne, capital of Victoria.

Melbourne is a city of arcades with clocks and mosaic floors, of 99-feet-wide streets and small parallel side streets bounding the "Golden Mile," where one can catch a tram for a 15-cent ride.

Melbourne, too, has its zoo. The 55-acre zoo was basking in the title of Royal Melbourne Zoological Gardens, approval by Queen Zlizabeth II just 120 years after the zoo had been established, the first in Australia.

Dr. James H. Sullivan is director, 11 years at Melbourne. He agreed with Dr. Crowcroft that it takes 10 years to re-structure a zoo and cited the difficulties in simulating environmental conditions for the animals. "We end with elephants among city trees and primates on artificial granite, but it is the only way to modernize, Zoos are set up not to protect animals from people but people from animals."

He told us of plans for a walk-through aviary that would show swamp-land to rain forest conditions - for birds from shores, heath, marsh and trees - an opposite exhibit from Taronga's rain forest.

We talked to the only woman keeper at the zoo. She reported it is "difficult for anyone to get into zoo work, even harder for a woman."

Melbourne Zoo has an education program for 65,000 children.

"Rug up," said the tour director. It was the night to drive south to Phillip Island to watch the parade of Fairy blue penguins.

The group did indeed bundle in extra jackets, gloves and scarves for the 60-mile trip to Western Port Bay and the sand dunes on the tiny island. We followed the Yarra River, said to "flow upside down," and watched koalas in tree along the road.

At dusk the small penguins swam out of the sea and rolled out of the surf, chugged around briefly, then marched up the beach to their burrows in the dunes, totally unmindful of the large group of visitors under floodlights watching the ancient rite. One bird on the beach charged back and forth greeting each new line of marchers. He acted as if he were seeking someone.

Later the naturalist told us "he's a young one - he's just letting them know he is ready to make the trip to sea with them!" The little penguins are found on the coasts of Southeast Australia and the flocks spend most of their life at sea.

We were leaving Australia. We had eaten barramundi, scallops, crayfish, beef and lamb; drunk the native wine and beer and sampled strange-named take-away foods; marveled at signs for "smash repairs," "panel beater," "furniture removal," "caravan parks." We had shopped for opals, sheepskins, woolens, aborigine artifacts and hoomerangs. We have fallen in love with the Aussie and his marsupials, monotremes, birds and flowers, but we were saying "Hooroo."

Kane is on the staff of The Washington Post's TV Channels magazine.

NEXT: New Zealand