2014
The fossil records of both Albatrosses and Petrels go back nearly 60M years; both are pelagic, since they only return to land to breed. Dominant in the Southern Oceans, albatrosses and giant petrels are convergent, so while not closely related, they have independently evolved similar traits as a result of having to adapt to similar environments.
Albatrosses comprise a group of 22 species of large to very large birds, and are among the largest flying birds. Both albatrosses and petrels are tube-nosed seabirds with strong and sharp-edged bills, with their upper mandible terminating in a large hook. Along each side of their bill are tubes (long nostrils) that enable albatrosses and petrels to measure their exact airspeed during flight – analogous to the pilot tubes in modern aircraft – and thus are highly efficient in the air. With their ability to use dynamic soaring and slope soaring, they are able to cover great distances with minimal exertion.
In addition to wingspans of at least 8-10 feet, albatrosses’ wings are stiff and cambered, with thickened streamlined leading edges. They travel huge distances using two techniques common to any long-winged seabird: dynamic soaring and slope soaring. Dynamic soaring involves repeatedly rising into the wind and descending downwind, thus gaining energy from the vertical wind gradient, with effort only expended in turns at the top and bottom of each loop. This maneuver enables them to cover about 600 miles a day without flapping their wings. Slope soaring uses the rising air on the windward side of large waves. Albatrosses’ very high glide ratios of 22:1 means that they can travel forward a distance 22 times the drop. Further, they are aided in soaring by a shoulder-lock, a sheet of tendon that locks the wing when fully extended, allowing the wing to be outstretched without any muscle expenditure, a morphological adaptation they share with the giant petrels.
All albatrosses are listed to be at some level of endangerment as a result of the serious decline in fish stock, from overfishing, and from being hooked by longline fishing gear. Both feed on squid, fish and krill, by either scavenging, surface seizing, or diving. And their breeding season can take over a year from laying to fledging with a single egg laid in each breeding attempt.
Combining their soaring techniques with their use of predictable weather systems, Albatrosses in the Southern Hemisphere flying north will take a clockwise route, while those flying south will fly counterclockwise. So well adapted to this lifestyle, their heart rates while flying are close to the basal heart rate when resting. Their flying intensity is such that the most energetically demanding aspect of a foraging trip is not the distance covered, but the landings, take-offs and hunting undertaken to find a food source.
Albatrosses live much longer than other birds; they delay breeding far longer and invest more effort into fewer young. Most species survive upwards of 50 years.
Capturing Albatrosses and Petrels in flight by camera, from a moving, bouncing ship in high seas is an exciting and exhausting challenge. With their habit of closely following ships for what might possibly be discharged, plus their natural tendency to glide within the ship’s draft, they definitely try to see just how close they can fly to the ship before having to veer off…
