The oldest known seabird is expecting at 66

First banded in 1956, the world's oldest known seabird has returned once again to Midway Atoll National Wildlife Refuge - and she is currently incubating an egg, officials said Saturday.

Wisdom, was first banded in 1956 and is identified by her red, plastic auxiliary band on her right leg (Z333) incubates her egg on Midway Atoll NWR. Source: AAP

The Laysan Albatross known as Wisdom, a bird thought to be at least 66-years-old, is incubating an egg once again, putting her on track to become the oldest breeding wild bird in the world.

Charlie Pelizza, the US Fish and Wildlife Service project leader at the refuge in the middle of the North Pacific Ocean,  said in a statement that Wisdom has been returning there for six decades.

"The staff was abuzz with the news that Wisdom was back and incubating," he said.

The bird was first banded in 1956. Since 2006 she has fledged at least nine chicks, and travelLed some three million miles over the course of her life.

Her mate, Akeakamai, was seen near their nest site on November 23.

The Midway Atoll National Wildlife Reserve is home to the world's largest albatross colony. 

Park staff had thought Wisdom might take a year off from breeding, as many albatrosses must take time to molt and replenish their plumage.

The birds spend almost 90 percent of their lives flying, traveling thousands of miles every year looking for food.

There's an estimated 3 million breeding birds year-round at the Midway Atoll refuge.

Wisdom and her mate Akeakamai. Source: USFWS