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 U.S. Geological Survey. "Simply incredible."

The chick, which scientists describe as healthy, hatched Sunday.

The mother, by now an old pro at the finer points of the birds and the bees, received her first identification band during the Eisenhower administration, in 1956. Back then, USGS scientist Chandler Robbins estimated she was 5 years old.

Since then, she has worn out five ID bands, returning year after year to lay an egg at Midway, a remote island northwest of Hawaii that was the site of a famous 1942 naval battle. Today, it's a U.S. 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 miles 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 traveled 50,000 miles a year as an adult. That's at least 2 million to 3 million miles 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 percent of the bird's world population nests on Midway. Researchers estimate that Wisdom has hatched up to 35 chicks in the past half-century.

As word has gotten out about her latest bundle of joy, scientists and birding enthusiasts are astounded.

"It's exciting," said Aimee Greenebaum, associate curator of aviculture at the Monterey Bay Aquarium. "If they are still being able to breed at 62, that's amazing. And it makes it more exciting to want to help conserve this fascinating species."

The aquarium, home to a Laysan albatross named Makana who was brought in with an injured wing, is believed to be the only aquarium in the world displaying one. In exhibits, aquarium employees highlight threats to albatrosses. They include plastic debris in the ocean, which the birds often ingest, sometimes fatally.

"People are going to say 'My gosh, a grandma is having babies,'" said aquarium spokesman Ken Peterson. "That's very cool. It can help connect people more closely with animals. When people have emotional bonds with animals, they care about them more.

"We have no way of knowing if Makana might be one of her offspring," he added. "She was born on Midway. Who knows?"

Paul Rogers covers resources and environmental issues. Contact him at 408-920-5045. Follow him at Twitter.com/PaulRogersSJMN.