One bird's year, and what a lost season costs

The kría flies 70,900 km a year to lay one or two eggs on open gravel

The kría, the Arctic tern, is here for about three months. The rest of her year she is flying. In August she leaves Snæfellsnes and goes south, and keeps going until she reaches the edge of the Antarctic pack ice, south of 58 degrees, in the Weddell Sea. What she is flying to is a patch of gravel.

When researchers fitted 1.4-gram geolocators to eleven of these birds, the average round trip came back at 70,900 km a yearprimary. The longest migration ever measured in any animal. One of the eleven was an Icelandic bird, from Flatey, in the bay on the other side of this peninsula.

She follows the summer, and sees more daylight in a year than anything else alive. She can keep it up for more than thirty years; the oldest anyone has ringed and found again was thirty-one years and eighteen days. Over a life like that the distance may pass 2.4 million kmprimary, which the people who measured it described as about three return journeys to the Moon.

She began breeding at about four. She spent the years before that at sea. And the entire return on that year, for her, is one or two eggs laid in a scrape on open ground. The average clutch is 1.96.official secondary

That is what the noise on the recording is. She is standing over the only thing the whole journey was for, and she will keep standing over it for as long as anyone stands there.

Sourced, line by line

The migration, the Icelandic bird, the Weddell Sea, the 2.4 million km and the thirty years are Egevang et al. 2010, PNAS, primary; and the Moon line is their phrase, quoted.

Lifespan, first breeding and clutch are BTO BirdFacts, from ringing and nest records.

Iceland holds 20–30% of the world's breeding Arctic terns across roughly 1,500 colonies. Náttúrufræðistofnun, and NAVE report 32-23 no resolving URL yet.

One figure deliberately absent: an Icelandic breeding-pair total came back from a secondary source visibly garbled. It is not on the site. The world share and the Red List move carry the point without it.

Will they come back? The most careful paragraph on the site

What we do not say. "They will never nest here again." The literature does not support it. Regional site fidelity is high, but dispersal to neighbouring colonies is frequent and normal, and Iceland has around 1,500 tern colonies that move. A colony that shifts a few kilometres has not necessarily been lost. Say it anyway and the first ornithologist who reads this page dismantles it, and everything else on the site inherits the doubt.

What is true, and is stronger. Iceland holds 20–30%official secondary of the world's breeding Arctic terns, so what happens on Icelandic gravel is a world-population question. The trend is already bad and officially so: kría moved from Least Concern in 2000 to Vulnerable in 2018. A species climbing that ladder is one where a lost season costs more than it would have thirty years ago. And a lost season is a full year of that arithmetic: one or two eggs, from a bird that flew 70,900 km to lay them.

And the honest close. Nobody counted this ground before the camp went up, and nobody is counting it now. So nobody can say what was lost, and nobody will be able to say whether they return: not us, not the festival, not the ministry. That is the failure, and it is the one this whole framework exists to prevent.