Tracking the Wandering Albatross
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This
bird spends most of its life on the wing.
The wandering albatross is a famous and mysterious bird
that few of us ever see. Its fame began with sea stories
in the days of sailing ships. Those few sailors who ventured
into the stormy waters of the southern oceans had a story
to tell. Their ships might be followed for days, even for
weeks, by an albatross gliding close behind.
There have been scientific studies of the wandering albatross as an interesting bird with a special way of life. To start with, it’s the largest seabird, weighing about twenty pounds and with a wingspan often more than ten feet. Its long, narrow wings are better for gliding than for flapping.
The wandering albatross also has two tricks that allow it to spend most of its life on the wing. Gliding looks easier than flying. But just holding wings outstretched takes work by a bird’s wing muscles. (Just try holding your arms outstretched for a few minutes. Even though you are not doing any useful work, your arm muscles will soon get tired.)
For the albatross, gliding is easy because of a tricky wing design. A sheet of cartilage can lock and hold the wing in position so that gliding does not take much work. That’s the first trick.
Uplifting
Air
The second trick has to do with ocean winds. Most gliding
birds, like the hawks and buzzards, are high flyers. They
use the upward-blowing air of warm updrafts to keep them
in flight.
The wandering albatross is a low flyer, usually skimming along a few feet above the waves. The waves are the key to the second trick. Ocean waves also make waves in the air above them. A wind blowing over the ocean surface has an upward swirl above every wave it passes.
You know about people who have fun using surfboards to ride the big ocean waves that come onto beaches. The wandering albatross is a wind surfer. It rides each little updraft that a wave gives to the wind blowing against it. Each updraft gives the bird enough lift to coast to the updraft of the next wave.
Where
Albatrosses Meet
Once every two years, the wandering albatrosses return to
the same lonely islands where they were born. Male and female
of a pair have a big greeting ceremony and then get to the
business of nest building, mating, and egg laying.
Both parents take turns at the forty-day job of incubating the egg. After that comes a 280-day job of feeding the chick. Male and female go out on flights of several days looking for fish and squid to feed the chick. After the chick learns to fly, it goes off on its own lonely wander, and the parents go off on theirs.
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The
dotted line shows the path of a male wandering albatross
as it flew among the islands (shown in pink) of the
southern Indian Ocean. |
Studies
on Land and Sea
The
wandering albatross has never known predators. It has no
fear of people and has been easy to study during its brief
homelife on land.
But how do you study the albatross during most of its life wandering over the oceans? Two French scientists figured out how to track the birds for long flights during the nesting season.
They put little radio transmitters on several birds. Then they could locate the birds’ positions every few hours by using radio receivers on two satellites. Observations from the satellites were sent to computers in France and were used to draw a map of each bird’s flight path.
On the map to the right, you can see the thirty-three-day, 9,400-mile flight path of a male out searching for food while the female was home incubating an egg. Details of the map told a lot that had not been known.
By day, the albatross traveled distances up to 600 miles. At night, flights were much shorter, and the bird often stopped to rest on the water. But it never stopped for longer than a few hours at a time. It lived up to its reputation as a wanderer.
When
the Wind Dies
One kind of weather the albatross did not like was a dead
calm with no wind at all. Then it would rest, taking only
short flights, waiting for the wind to come. That need
for wind explains why the wandering albatross lives where
it does—only in the southern ocean around Antarctica,
the windiest of all the seas.
Satellite tracking has taken away some, but not all, of the mystery from the wandering albatross. We can only wonder how these birds navigate and find their way where there are no signposts or landmarks. How do they travel thousands of miles on erratic or even zigzag courses, and how does each find its way home to a tiny speck of an island?
