How albatrosses fly, find food, and nest

SS_WanderingAlbatrossPair_MZPHOTO.CZ_660
Adult (left) and immature Wandering Albatrosses fly at South Georgia Island. Photo by MZPHOTO.CZ/Shutterstock

Albatrosses are large, heavy birds with goose-like bodies and long, narrow wings. The smaller species have wingspans of 6 to 8 feet, while those of the Royal are about 9. The wingspan of the Wandering, the longest of all birds, can exceed 11 feet. The long, very narrow wings are the most efficient for flight of all birds because a narrow wing has less drag. This principle carried over to airplane design when gliders were given albatross-like wings. The lift of any wing can be increased most dramatically by increasing speed — either the wing moving more rapidly through the air (strong engine) or air moving more rapidly over the wing (strong winds). It is the latter that commits albatrosses to high-wind environments mostly in the southern oceans.

While their wings are efficient for sailing, they’re a liability for takeoff and landing. The birds often nest on the windward side of high areas, where they can drop into air for takeoff or, if on the ground or water, run into the wind to build up speed. Landings are often comical as the narrow wings do not allow a slow approach. The birds often land on their feet and then tumble forward, sliding on their bellies and breasts. (It’s the source of the name gooney bird.)

The favorite foods of albatrosses include large zooplankton (krill) and squid plus dead animals on the ocean surface (carrion). Krill are associated with large masses of phytoplankton and are tied to upwellings, regions of the oceans with vertical currents that bring nutrients to the surface. This creates a very patchy distribution. For albatrosses, finding plankton is like finding the proverbial needle in a haystack — so they have developed a clever “finder.”

For a long time, researchers have known that albatrosses and some other bird species have a well-developed sense of smell. Gabrielle Nevitt, an ornithologist at the University of California, Davis, has been studying albatrosses and the relationship of olfaction to food finding. Early on, it was discovered that air and water samples downwind from masses of plankton contained dimethyl sulfide (DMS), a pungent gas that could be detected by albatrosses.

How albatrosses detect food

Nevitt and her team placed high-precision GPS loggers on Wandering Albatrosses to precisely map their flight patterns, and they implanted temperature-recording devices in their stomachs to determine when they were feeding. We now know that albatrosses fly at right angles to the wind direction until they detect DMS and then turn upwind and follow the scent to its source — a plankton community. Sometimes they can find it visually, seeing live or dead birds on the surface. If they lose the scent, they’ll fly in a zigzag pattern to find it again.

So, what’s the source of DMS? As zooplankton feed on phytoplankton, they literally chew them, breaking cells open, which allows a complex chemical inside to flow into the seawater. Specialized bacteria in the seawater metabolize this chemical for energy and, in the process, release the byproduct, DMS.

Most albatross nests are simple scrapes in the ground or a mud mound. The female lays a single white egg, and both sexes share incubation, which lasts about 60 to 80 days. Both sexes feed the youngster by regurgitating food, and this continues for up to three months in smaller species and up to nine months for the large ones. The nesting cycle of Wandering Albatrosses is so long, they can’t complete it in one year. So, they nest every other year.

When young albatrosses become independent and leave their nest site, they begin a multi-year foray on the open ocean and will not return to land until they are old enough to breed. This process takes about seven years in the Laysan Albatross (and other smaller albatrosses) and very likely takes longer for the Wandering.

Dying winds are a nemesis for albatrosses. When becalmed, albatrosses are essentially “grounded” and spend much time sitting on the water.

Most of the 15 albatross species occur in the southern oceans, but three species — Laysan, Black-footed, and Short-tailed — occur in the north Pacific. While fossil albatrosses are known from the north Atlantic, no albatrosses are found there today. Albatrosses of the southern oceans are most numerous in the stormy latitudes between 40 and 50 degrees. This region, characterized by fierce and constant westerly winds, is a continuous band of open seas extending around the world. It is no wonder that these albatrosses can sail around the world. It is estimated that the Wandering Albatross can master that distance in a Jules Verne time of 80 days.

Steeped in lore and admired by all, albatrosses have found their niche in some of the most inhospitable regions of the globe. From sailors to birdwatchers, humans continue to be captivated by them. Albatrosses are clearly among the most amazing of birds.

 

This article from Eldon Greij’s column “Amazing Birds” appeared in the November/December 2017 issue of BirdWatching.

 

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