One of the most remote places on Earth, it became the focus of world attention in June 1942 when one of the decisive sea battles of World War II took place near it. Four Japanese aircraft-carriers and a heavy cruiser were sunk by the Americans, who lost one carrier and a destroyer.
But Midway has another claim to fame; nearly two million seabirds gather there each year. A wildlife reserve, with the easily remembered name of Papahánaumokuákea, was established in 1988 to protect what are known locally as ‘gooney birds’; the place is home to almost 70% of the world’s Laysan albatrosses, and 40% of the world’s black-footed albatrosses. A pair of short-tailed albatrosses bred there for the first time this year. The world population of this species is down to about 2,000.
But one Midway resident has become a world celebrity. A Laysan albatross, known as Wisdom, was caught and ringed while nesting in 1956. Extraordinarily, she is still alive. Albatrosses don’t breed until they are at least five years old and most don’t do so until they are eight or nine, so Wisdom is at least 61. Hers is the longest life-span ever recorded for a bird in the wild. She is estimated to have flown at least five million kilometres, the equivalent of six round trips to the moon.
Albatrosses lay only one egg each year and it takes months to raise a chick. Parents sometimes take a year off after breeding so Wisdom has probably produced between 30 and 35 offspring.
The tsunami which followed the recent Japanese earthquake killed thousands of seabirds at nesting colonies on low-lying Pacific islands. The two-metre wave struck Midway at 1.25am on March 11. There had been a four-hour warning, so the 60 people living there were safely ensconced on the third floor of the local hotel. Although the airport was put out of action, serious damage was limited.
Wildlife fared less well. Huge numbers of Bonin petrels drowned in their nesting burrows and thousands of fish were stranded high and dry. Two green turtles had a lucky escape. Carried by the wave to the middle of an island, they survived and were returned to the sea.
Adult albatrosses can take wing if suddenly threatened but, according to a Reuters report, 2,000 were caught off-guard and swept to their deaths. About 110,000 chicks perished. Against the odds Wisdom, despite her great age, survived and so did her chick; it was found alive and well about 35 metres from the nest site. The short-tailed albatross pair’s youngster also survived but the parents could not be found.
Wisdom is of special interest here because the previous longevity record was held by an Irish bird. In July 1953, a Manx shearwater was captured and ringed at its nesting burrow on Copeland Island, Co Down. It was re-trapped there in July 2003. As a breeding adult, it must have been at least five when ringed, so it was not less than 55 years old when last seen.
Albatrosses and shearwaters belong to the same order of birds and have similar lifestyles. Both spend virtually their entire lives at sea, flying enormous distances. Once fledged, they come ashore again only to breed. Having to live full-time on the ocean wave seems a daunting prospect but, covered in thick water-proof plumage and equipped with glands to remove salt from seawater, an austere but secure livelihood is possible.
Food is plentiful and, apart from the occasional orca, there are no predators. But to lay and incubate eggs, seabirds must return to land. Equipped for a pelagic lifestyle, they are like fish out of water when ashore. Nesting is possible only on inaccessible cliffs or remote islands where predators such as foxes stoats and rats aren’t present. Such locations are in short supply and huge seabird cities form as birds crowd into limited accommodation. Baby-food shortages develop as the local fish stocks become exhausted. Only one youngster can be raised and so, to replace itself, a seabird must live a very long time.