In the end, it was nature that triumphed and astounded. Two days after experts had declared her calf dead in the womb, Taronga Zoo's Asian elephant matriarch, a first-time mother, squatted in a corner and gave birth without any human help.

Three hours later, when her keepers arrived about 6.30 on Wednesday morning, she was standing calmly at the door from the barn to the paddock.

She did not react when they entered, she did not turn when they called her name.

The unusual behaviour made Katharina Theodore worried.

''She seemed to be in a stupor,'' the keeper recalled yesterday. ''I started to get quite upset.''

But the sight of blood on the elephant's legs brought a sense of relief. It meant Porntip had expelled the calf and they could focus on returning her to good health.

Ms Theodore and elephant manager Gary Miller quickly spotted the newborn lying outside the barn, about a metre from its mother.

''And then, mindblowingly enough, the calf raised its head,'' said Ms Theodore, who admitted yesterday she was still in shock.

She shouted: ''It's alive, It's alive,'' before her training kicked in and she set about caring for the calf.

Zoo senior veterinarian Larry Vogel said the CCTV footage showed Porntip had pushed the baby around soon after it was born, as elephants do, to stimulate it.

But the 116-kilogram calf was very weak from nine days of difficult labour, part of which he apparently spent in a coma, and could not get up.

The three-hour delay before veterinarians arrived ''doesn't seem to have had a detrimental affect on the calf'', Dr Vogelnest said, adding that the calf's progress had been ''quite phenomenal''.

Dubbed Baby Boy and Mr Shuffles - ''He's got an old-man shuffle going on at the moment,'' said Ms Theodore - the little elephant, who is getting massages for very stiff muscles and a weak left side, has already tried to run, and can suckle on his own.

Dr Vogelnest said the calf appeared to be mentally well, and was co-ordinated and exploring his surroundings, and went ''straight for the nipple''.

Infection remains a risk. ''But the evidence so far is that he is going to do well,'' he said.

Zoo director Cameron Kerr said the unexpected live birth showed how much people had to learn.

''Nature has given us the most wonderful turn of events, and the most wonderful surprise,'' he said.

Yesterday the other elephants gave up breakfast to run and see the new calf.

The experts had declared it dead in the womb on Monday when they could detect no signs of life.