March 25, 2011 – Brett Leverett
In the wake of an 8.9 magnitude earthquake just outside of Japan, a devastating tsunami swept throughout the Pacific Ocean damaging everything from nuclear power plants to wildlife refuges. Tsunami warnings ranged as far away as Alaska, but the brunt of the impact was taken much closer.
The oldest free-flying bird was residing on Sand Island, a part of a National Wildlife Refuge between Hawaii and Japan, when the tsunami struck on March 11. This 60-year old albatross was one of nearly a million Laysan albatross which reside in the refuge.
Midway Atoll National Wildlife Refuge is composed of three islands within a reef only about 5 miles across. The quake generated four successive waves with the tallest at 1.5 meters. These waves pounded the refuge, nearly completely immersing one island.
The series of waves killed an estimated 2,000 adult albatrosses and about 110,000 chicks in the refuge. While these numbers are only a fraction of the total population, nearly 20% of this year’s hatchlings did not survive.
To the surprise of many, federal officials announced on Tuesday that the elderly bird named Wisdom and her recently hatched chick were spotted alive about a week after the tsunami hit.
“It’s a dangerous world out there. There’s lots going on, so I would say she’s very lucky… Although wildlife biologists generally manage at the level of populations, we, too, become entwined in the fates of individual animals. Wisdom is one such special creature,” Barry Stieglitz, project leader for the Hawaiian and Pacific Islands National Wildlife Refuge Complex, said in a statement.
Wisdom, a 60 year old Laysan albatross, holds the record as the oldest wild specimen documented during the 90-year history of the U.S. and Canadian bird-banding research program. She was initially tagged with her aluminum identification band in 1956 and was estimated to be five years of age at that time.
“Because she is the oldest, she’s able to provide us some information that no other albatross can at this point in time, and that’s exactly how long-living are these animals,” Stieglitz said. Biologists estimate that Wisdom has logged about 3 million flying miles in her lifetime, the equivalent of six round trips to the Moon.
All but two of the 21 species of albatrosses are in danger of extinction, according to the International Union for the Conservation of Nature.
The birds commonly drown after diving for bait used for long-line fishing, or die from being hooked on a long-line dyed blue for the night. According to the United States Geological Survey, chicks’ deaths can be credited to lead poisoning from old paint, and from dehydration caused by being unknowingly fed regurgitated food containing plastic and other trash floating in the ocean.
The Laysan albatross breeds on the Hawaiian islands of Oahu and Kauai and feeds off the western coast of North America, including the Gulf of Alaska. One will spend its first three to five years in constant flight, never touching land, and is believed to even sleep while aloft.
After their first three to five years in flight, they return to their colony but do not mate for their first time until seven or eight years old. During their return time at the colony they form pair bonds with a mate they will typically keep for life. Courtship involves a process of elaborate dances with have up to 25 ritualized movements.
Occasionally the birds form homosexual pairs consisting of two females. This has been observed in colonies where the sex-ratio of male to female is two to three. Unpaired females pair up among themselves and successfully breed. These eggs are commonly fathered by already paired males, who “cheat” on their spouse.
Although Wisdom has outlived her spouse, many female Laysan also form permanent bonds amongst themselves to help cooperatively raise their young.
Wisdom’s latest chick, believed to be her 35th, hatched nearly a month ago making her not only the oldest free-flying bird, but also the oldest free-flying mother at the age of 60.
Photo source USGS