115 days. No food. One egg on his feet.

1 April · day 1 of 115

The walk inland

At the end of the Antarctic summer, the emperors leave the open water and walk inland — about a hundred kilometres — to the colony ice.

This winter is set at Pointe Géologie, where some 3,000 pairs gather within earshot of a French weather station. The male arriving now weighs nearly 38 kilos. He will not eat again for about 115 days.

• ≈38 kg on arrival
• ≈100 km from the sea
• ≈3,000 pairs

2 May · day 28

A single egg

Each female lays one egg — about 445 grams. In May 2001, all five tagged females at Pointe Géologie laid within a single week, 16 to 22 May.

One egg. No nest. Nothing between it and the ice but feet.

3 19 May · day 46

Take the egg

She lays it onto her own feet, then — quickly, clumsily, with the whole season at stake — rolls it onto his. Then she turns and starts walking to the sea. She will be gone about seventy days.

The egg is on your feet. It weighs about 445 grams and must be held at 36 °C (97 °F).

4 Late May · June · days 47–78

She walks to the sea

While he stands, she travels. In the winter of 1993, satellite tags watched females walk to the ice edge in about eight days, feed at sea for fifty to sixty, and walk back in four — some seventy days away, a hundred kilos of krill and fish eaten, six kilos gained.

He does none of that. He stands, loses 119 grams a day, and waits.

She is 1 day gone — walking to the sea.

5 21 June · day 79

The longest night

Two hours and one minute of sun; the other twenty-two hours the sun never clears the ice. Across the whole incubation, nearly three quarters of every day is night — and it is at night that he huddles: 96% of all huddling happens after dark.

Nine degrees further south, at Halley, the sun stays below the horizon from 30 April to 13 August. Here it still climbs, barely, above the ice.

6 Late June · July · days 80–110

What the huddle knows

He huddles more than a third of his time — thousands of males packed about twenty-one to the square metre, shifting every 30 to 60 seconds in waves that cross the huddle at twelve centimetres a second.

Storms rake the colony for days at a time — winds of 324 kilometres an hour have been recorded at the station 500 metres away.

Inside, the air he breathes can rise above 0 °C (32 °F) while outside it is about −17 °C (1 °F). In the tightest huddles it can pass 20 °C (68 °F). The hottest air logged in the Pointe Géologie study reached 37.5 °C (99.5 °F).

He holds his own core at 36.9 °C (98.4 °F) and burns almost pure fat: ninety-six parts fat to four of protein. But the mass bar only runs one way, and day 110 ends about half a kilo above the 24-kilo line — below it, the fast turns on him.

7 23 July · day 111

Born before she returns

Midwinter. The chick breaks out of the shell — and she is not back.

So the father feeds it himself — a pale curd from the wall of his own gullet, the secretion Prévost and Vilter described in 1963, made from a body that has eaten nothing for 111 days. It lasts days, not weeks. It is enough — if she comes.

8 Late July · days 112–115

Her voice finds him

She comes back from the sea after seventy days away and calls into a colony of thousands. He answers. They find each other by voice alone.

An emperor sings with two voices at once, and where they overlap they make a beat — a wobble unlike any other bird's in the colony. Play a mate's call with one voice stripped out and the bird does not answer; play the beat and it does. Fifty-eight calls from seven birds, and every one told apart.

9 Late July · day 115

His turn to eat

He hands the chick across — one more careful roll from feet to feet — and starts walking. Ahead: the sea, and his first meal in 115 days. Behind: a chick that will join a crèche.

115 days13.7 kilos lostone egg

The night is long. Hold someone warm.