The silent, enigmatic snow leopard is a species in danger, but Dublin Zoo now has two new cubs to call its own. Eileen Battersby visits them in their first few days of life

Anxiety has begun to replace restlessness. The young female knows something new is about to happen to her although there is no enemy, no obvious threat. A subtle expression of unease is beginning to flood her calm, small, creamy-grey features. This is refined distress, choreographed over the centuries. The bewildered dance must be danced and she must look to instinct to teach her the steps.

She scratches about in the bedding, fusses to the point of fretting.

Suddenly, her customary independence wavers and her pale green eyes widen. She needs support, companionship, and calls to the male. He is nearby, watching; fascinated, concerned and respectful. The seven-year-old snow leopard is about to give birth. It is her first litter.

This birth has been orchestrated. It is not happening in solitude high in the Himalayas at an altitude of 5,000 metres. Instead the snow leopard awaits her biological destiny in a den that has been carefully constructed for her by man, not God. A camera is recording the miracle. It is about 5.40pm on May 4th and the setting, far from the mountainous habitat of the snow leopard, is Dublin Zoo.

As her first cub is born, Ciara appears surprised by its arrival. She stands up and seems to ask: 'Who put this here?' There is a interlude of about 20 minutes before the next cub appears. By then, Ciara has become more practised, almost authoritative, and regards the third arrival 40 minutes later as expected. In just over an hour, her first family, a male and two females, weighing in at about 250g respectively, is complete.

She licks each one, the fretting forgotten. The maternal inspection continues, three cubs in a row, tended in turn as they would have been in the wild. The zoo staff are ecstatic.

Breeding snow leopards, Uncia uncia, in captivity is never easy. They are solitary, elusive, non-vocal, high- altitude natives of the mountains of Central Asia, from the Hindu Kush in Afghanistan eastward along the Himalayas to Tibet and southern China, and also northward to the mountains of eastern Russia and west China and on to the Sayan range on the Siberian border of Mongolia.

Little is known about snow leopards. They live in air so high and cold and thin that they have no need of an immune system. They are also at the top of their ecosystem, capable of killing animals three times larger than themselves, so they know no fear. In the wild, they live on sheep and goats, as well as deer, boars, marmots, hares and mice. Their only enemy is man, who kills them for their beautiful fur and also for various body parts used in traditional Chinese medicine. Farmers also shoot snow leopards discovered stalking their stock.

The smallest of the big cats, they are yet another critically endangered species, with less than 7,000 living in the wild and a current international zoo population of 476.

In 1973, American writer and naturalist Peter Matthiessen set off with zoologist George Schaller to the Crystal Mountain in Tibet, motivated by "the hope of glimpsing this near-mythic beast". Matthiessen's quest, shaped by his admiration for the beauty, deadly hunting skills and athleticism of this enigmatic, brilliantly camouflaged cat, resulted in a classic book, The Snow Leopard (1978). Ironically, or perhaps true to the legendary mystery of the snow leopard, he never saw one.

Considering all these factors, the excitement in Dublin Zoo, a member of the EAZA (European Association of Zoos and Aquaria) breeding programme, is understandable. To date this year only 10 snow leopard cubs, including the Dublin trio, have been born in Europe's 300 zoos. Three were single births, while Berlin Zoo and France's Doué-la-Fontaine Zoo had twins.

Ciara's three cubs did well from birth. They looked well and happy, as tiny as newborn puppies, sleeping when not feeding, when I first saw them at four days old.

At eight days, keeper Gerry Creighton - who previously (with his father, Gerry senior) hand-reared Patrice, a snow leopard cub born in Dublin Zoo in 1988 and rejected at birth by its mother - did a routine check but could only find two cubs. On searching the bedding, he discovered the largest cub, the male, dead in the straw. He had been carefully buried by his mother. Two ribs were crushed. Ciara had simply rolled over on him. Had he been a few weeks older and bigger, he would have survived.

The two females are now just over five weeks old and weigh 1.42kg each. Their eyes opened at 12 days and they are beginning to explore, following their mother to the door of their den when she visits her enclosure, which has been designed to create some sense of the rocky environment that would have been her natural habitat had she been born in the wild. Outside, Ciara sniffs the air and pads over the rocks. She stays outside for about 20 minutes before returning to her cubs.

Meanwhile, her mate, Tito, remains relaxed. Also seven years old, he was bred in an Estonian zoo and was moved to Nordens Ark Zoo in Sweden, where he fathered three cubs in two separate litters. He arrived in Dublin shortly before Christmas and, having been recommended by the stud-book keeper, impressed everyone, including his intended, whose two previous attempts at mating had failed. (The first relationship ended acrimoniously and the male was moved to another zoo, while a second mate from Edinburgh Zoo, who proved compatible, swallowed a stone and died.)

Ciara's rapport with Tito developed well, and their courtship and the birth of their cubs will feature in a film to be broadcast on RTÉ to coincide with the cubs going on public display in the snow leopard enclosure, when they will also be named.

Snow leopard pregnancy lasts about 100 days. Eleven years ago, three cubs were born in Dublin and were later moved to three German zoos as part of the EAZA breeding programme. Ciara was born in Marwell Zoo in England in 1999 and arrived in Dublin in 2000. She and Tito will mate again.

Females mature at three years of age, males at four. The young Dublin females will stay with their mother until they are about 18 months old. In the wild, they are weaned at three months and leave their mother by the age of two to establish their own territory.

It's a summer evening, and Ciara gazes at us. A self-possessed, almost serene character, she is interested, rather polite. There is no aggression, just dreamy interest. Her huge paws, with their thick furry soles, contrast with her small face. Built for the snow and freezing temperatures, she has a short neck and a long tail that wraps about her, warming her nose and mouth if needed. Her creamy-to-slate-grey coat is natural camouflage. She has enlarged nasal cavities for breathing at high altitude, but no roar - she doesn't need it, as snow leopards communicate by scent markings.

It is getting late. She turns, and her fabulous tail, as thick as a large snake, is the last trace of her to disappear back into the den. The cubs resume climbing over her. Outside, Tito surveys the enclosure, jogs past us, and then sits on the top of his rock ridge, interrupting his reverie for a final stretch before settling down to sleep.

• Dublin Zoo is open on Mon-Sat, 9.30am-6.30pm, and Sun from 10.30am