「世界最高齢」のアホウドリ、７４歳で再び産卵

【ロサンゼルスＡＦＰ＝時事】若くて体力があっても子育ては大変だが、高齢のアホウドリが再びその試練に挑もうとしている。年齢は７４歳で、野鳥の繁殖では世界最高齢とみられている。（写真は、米ミッドウェー環礁国立自然保護区で、コアホウドリ「ウィズダム」が産んだ卵を温めている新たなつがい相手〈左〉）
　太平洋のミッドウェー環礁国立自然保護区では毎年、数百万羽のコアホウドリが巣作りをしている。雌の「ウィズダム」もその一羽だ。
　コアホウドリは「一夫一妻主義」で知られ、野生動物の専門家によると、ウィズダムは数十年にわたって同じつがい相手と繁殖を続け、これまでに５０個以上の卵を産んできた。
　だが、以前のつがい相手は数年前から姿を見せず、ウィズダムは最近、他の雄との求愛行動を見せていた。
　今年は新たなつがい相手との間で産卵。その雄も卵を温めるのを手伝っている。
　ウィズダムは１９５６年に同保護区で最初の産卵を行った際に識別され、足環を付けられた。この時点で少なくとも５歳だったため、今月末までには少なくとも７４歳か、それ以上の年齢に達すると思われ、年齢が確認された野鳥としては世界最高齢とみられている。
　コアホウドリは食料を求めて１５００キロ以上を移動する。
　また、小型の鳥の寿命は２～３年だが、アホウドリやペンギンなどの海鳥の寿命は場合によって４０～５０年に及ぶ。【翻訳編集ＡＦＰＢＢＮｅｗｓ】
〔ＡＦＰ＝時事〕（2024/12/13-20:39）

Parenting can be tough, even for the young and energetic, but one elderly albatross is about to go through it all again -- at the ripe old (and apparently record-setting) age of 74.
Wisdom, a Laysan Albatross, is one of millions of the huge seabirds that return to Midway Atoll, near Hawaii, every year to nest.
Wildlife experts say for decades she was doing this with the same partner -- the birds are known to be monogamous -- and has laid over 50 eggs in her lifetime.
But her partner has not been seen for years, and Wisdom has recently begun to flirt with other males.
On this year's visit, she has produced an egg that her new partner is helping her to incubate.
We are optimistic that the egg will hatch, said Jonathan Plissner, supervisory wildlife biologist at Midway Atoll National Wildlife Refuge.
Photographs and video provided by the US Fish and Wildlife Service show the proud parents-to-be apparently chattering to their egg before the male sits on it.
Wisdom was identified and tagged when she laid her first egg at the refuge in 1956, when she would have been at least five years old -- the point Laysan Albatrosses reach sexual maturity.
That means by the end of the month, Wisdom will be at least 74 years old, and could be several years beyond that, making her the oldest known wild bird in the world.
Laysan Albatrosses can have a wingspan of up to 80 inches (203 centimeters) and travel upward of 930 miles (1,500 kilometers) to forage for food.
The average lifespan of birds varies greatly by species. Small birds often live just two to three years, while seabirds -- including albatrosses and penguins -- sometimes make it to 40 or 50. Parrots, alone among birds, can outlive humans, with one cockatoo allegedly making it well past 100.
There are more than a dozen species of albatross, found across the Southern Hemisphere as well as in the North Pacific Ocean.
The birds have long featured in stories of life at sea, notably in Samuel Taylor Coleridge's The Rime of the Ancient Mariner, in which a sailor brings misfortune on his ship by killing one of the birds, whose corpse is then hung around his neck.