Gave birth ... the Laysan Albatross, Wisdom, pictured with her newly hatched chick, at Midway Atoll National Wildlife Refuge in March, 2011.

Gave birth ... the Laysan Albatross, Wisdom, pictured with her newly hatched chick, at Midway Atoll National Wildlife Refuge in March, 2011. Photo: US Fish and Wildlife Service

The world's oldest-known wild bird—a 62-year-old albatross on Midway Atoll in the Pacific Ocean—is also a new mother.

The bird, a Laysan albatross whom biologists have named Wisdom, hatched a chick this week, her sixth in the past six years.

"If she were human, she would be eligible for Medicare in a couple of years, yet she is still regularly raising young and annually circumnavigating the Pacific Ocean," said Bruce Peterjohn, chief of the North American bird banding program at the US Geological Survey. "Simply incredible."

The mother received her first identification band during the Eisenhower administration, in 1956. Back then, USGS scientist Chandler Robbins estimated she was five years old.

Since then, she has worn out five ID bands, returning year after year to lay an egg at Midway, a remote island north-east of Hawaii that was the site of a famous 1942 naval battle. Today, it's a US national wildlife refuge where hundreds of thousands of albatrosses nest every year.

Albatrosses lay only one egg a year. Legendary long-distance marvels of the animal kingdom, they fly thousands of kilometres across the ocean, gliding on wind currents with their large wings. They feed on fish, squid and other marine life.

Researchers estimate that if Wisdom flew typical routes, she quite probably has travelled 80,000 kilometres a year as an adult. That's at least 3 million to 4 million kilometres since she was first banded, the equivalent of four to six trips from Earth to the moon and back.

Most Laysan albatrosses live between 12 and 40 years, although some have been documented surviving into their 50s. About 70 per cent of the bird's world population nests on Midway. Researchers estimate that Wisdom has hatched up to 35 chicks in the past half-century.

San Jose Mercury News