World's oldest known wild bird lays egg at 74

Wisdom (L), identified by her Z333 tag, watches as her partner tends to the egg

The world's oldest known wild bird has laid an egg at the approximate age of 74, US biologists say.

Wisdom, a Laysan albatross, was filmed by the US Fish and Wildlife Service (USFWS) at the Midway Atoll national wildlife refuge in the Pacific Ocean with her latest partner looking after the egg.

Members of the species usually only live for 12-40 years, but Wisdom was tagged in 1956 when she was about five.

Her last offspring hatched in 2021. She is thought to have had more than 30 chicks in her lifetime.

The USFWS said on X that Wisdom was with a new partner this year and that her previous partner Akeakamai had not been seen for several years.

The species generally mates for life but she is already thought to have outlived at least three mates.

Jon Plissner, supervisory wildlife biologist at the refuge, told BBC Radio 4's Today programme that Wisdom was one of two to three million Laysan albatrosses who travel to Midway to breed.

He said biologists were unaware of any other birds even close to her age, the oldest being 45.

"It's really been remarkable," he said. "Wisdom seems to pique the interest of people across the world. We wait each year with bated breath for her return."

He said Wisdom still appeared to have the energy and instincts to raise another chick, and that there was a 70-80% chance of the egg hatching.

Albatross parents share incubation duties and, once the chick hatches, feeding duties.

Wisdom was first identified and tagged in 1956 after laying an egg. Laysan albatrosses are not known to breed before the age of five.

Midway Atoll is part of the Hawaiian archipelago but does not fall within the US state of Hawaii and is described as an unincorporated territory of the US.

The wildlife refuge is home to the largest colony of albatross in the world.