The albatross—master aviator of the ocean winds
Graceful. In control. Effortless. That’s how the wandering albatross (Diomedea exulans) has appeared to generations of sailors on the far-flung seas, who marvelled at its ability to stay aloft without flapping its wings.
The albatross is known to travel up to 16,000 km (10,000 miles) in a single journey, and circumnavigate the globe in 46 days.1,2 Flying no higher than about 20 metres (65 ft) above the sea surface, the albatross searches the vast expanses of the ocean for squid and fish to eat, and can spend months, even years, at sea.
Around half its time is spent diving for food or floating on the surface; the rest of the time the albatross remains airborne. A supremely energy-efficient long-distance forager, in favourable flying conditions its in-flight heart rate (an indicator of energy use) is nearly as low as its base heart rate when at rest on land.3
Other birds are also known for effortless long-distance flight without wing-flapping. Pelicans, for example, ride thermal updrafts of air to soar to great heights, before gliding downwards over great horizontal distances. But out on the open water away from any sun-heated land there are no thermal updrafts to ride, or currents of air forced upwards by mountain ranges or coastal cliffs for the albatross to soar. So how does the albatross do it?
It seems able to stay aloft at will, continuously gliding hither-thither in a series of graceful side turns, pull-ups, and descents, above the ocean waves.
But only when the wind is blowing.
If the wind eases to less than about 16 knots (30 km per hour) the albatross cannot soar. And while its long, narrow wings are fantastically suited to gliding/soaring, it’s a different story when it comes to flapping. So because albatrosses are incapable of sustained flapping flight, this means that when the wind abates, the albatross is forced down and must rest on the ocean surface until the wind picks up again.
It’s no coincidence, then, that albatrosses tend to be found in the exceptionally windy southern latitudes of the ‘Roaring Forties and Furious Fifties’, from Antarctica to South Africa, Australia, and South America. In the North Pacific, albatrosses can be found traversing the ocean expanses stretching from Hawaii to Japan, Alaska, and California. Equatorial seas, with their famous low-wind ‘Doldrums’, are devoid of albatrosses—an exception being the area around the Galápagos Islands, where winds are stronger thanks to the influence of the cool waters of the Humboldt Current.
In Samuel Taylor Coleridge’s famous 1798 epic, The Rime of the Ancyent Marinere, the sailor who killed the albatross is on board a becalmed sailing ship. Since albatrosses can’t survive where there is no wind, the dead bird around his neck would seem an apt metaphor. But give an albatross more than an average sea breeze, and its mastery of the air above the waves is supreme.
Researchers, hoping to one day emulate the albatross’s prowess in the flight of drones and other Unmanned Aerial Vehicles (UAVs), have been steadily peeling back the mysteries of how this avian aviator so adroitly uses the ocean winds to power its flights. The albatross is a master of what is now known as dynamic soaring, whereby this remarkable bird uses differential wind speeds (‘wind shear’) near the surface of the ocean to extract energy from the wind.4
Exploiting the wind shear zone
As every student of flight and air movement knows, the bottom-most layer of wind blowing above any surface, including water, will incur friction and thus slow down. This layer itself then becomes an obstacle that in like manner but to a lesser extent slows the layer of wind immediately above, which in turn somewhat slows the layer above it, and so on. Thus at 20 metres altitude, the wind will be significantly stronger than at sea level, with a gradient of intermediate windspeeds in between. It is this 10- to 20-metre–high wind shear zone above the sea surface that the albatross exploits to power its flight.
There are four easily-discernible phases in each flight cycle. First, a windward climb, then a curve from windward to leeward (i.e. downwind) at peak altitude, then a leeward descent, and finally a reverse turn close to the sea surface that leads seamlessly into the windward climb of the next cycle. The albatross does not flap its wings during any of these phases; in fact its wings are firmly held in outstretched position by a shoulder-lock system that allows the albatross to keep its wings open without any muscular expenditure. (The albatross shares this feature with the giant petrels—see box: The albatross and the Ark.) The only muscular effort expended is in controlling the turns.
The key as to how dynamic soaring permits sustained flight is in the albatross’s change in direction. During the first phase when facing windward, the albatross loses much of its energy to drag and converts the rest into gravitational potential energy as it climbs. The energy gain comes at the highest point of the flight cycle as the albatross turns leeward. As it glides downwind, the wind exerts a propulsive effect throughout the descent which gives the albatross a maximum total energy near the base of the descent. When turning back from leeward to windward the albatross will inevitably lose energy but because wind speeds are much slower near the surface of the water, the albatross achieves a net surplus of energy. So dynamic soaring enables the albatross to extract sufficient energy from wind shear near the ocean surface so as to be able to fly in any direction, even against the wind, with hardly any effort. As one group of researchers put it, in a write-up entitled The nearly effortless flight of the albatross:
“The bird still has a ‘propulsion profit’ over the whole cycle that just manages to overcome drag. As long as it keeps up that pattern of dips, swoops, and turns, it can keep on flying—flying for free.”5
‘Flying for free’—by design!
The fact that aero-engineers want to incorporate the ‘flying for free’ lessons from the albatross in their designs of drones5,6 and other UAVs4 points to the albatross itself having been designed with the capability for dynamic soaring. And of course the albatross couldn’t exhibit this behaviour without also having the necessary infrastructure. E.g. along each side of its bill are two nasal ‘tubes’, thought to be analagous to the Pitot tubes of modern aircraft which measure airspeed.7 Instantaneous accurate information about airspeed allows the albatross to make split-second decisions on when to turn, etc., necessary to perform dynamic soaring. Pitot tubes are in planes by design and so too the equivalent in the albatross. And just as the wing-lock systems of naval aircraft with folding wings were designed, similarly the wing-lock system in the albatross. Not to mention the plethora of other essentials needed for even just basic flight,8 let alone the kind of aerial mastery the albatross exhibits in its own special zone just above the windblown waves. Who’d have thought that any creature would have the capacity to spend much of its life in such a zone, in such a manner, in areas so vast and seemingly empty? But as the psalmist wrote:
O Lord, how manifold are your works! In wisdom have you made them all; the earth is full of your creatures. (Psalm 104:24)
The Albatross and the Ark
In an extremely powerful refutation of local-Flood theories, Genesis 7:14 says that “every bird, according to its kind” entered the Ark—thus including the albatross. Given that this bird is generally considered by Jewish scholars as being unclean in reference to Mosaic law, Noah would have only taken one pair of the albatross ‘kind’ aboard the Ark (Genesis 1:20–23, 6:19–20), cf. the seven he was commanded to do for clean birds (Genesis 7:2–3). Note that kind is not the same as ‘species’ or even ‘genus’, which are human (ever-changing!) constructs, and of which there are plenty among the albatrosses.
Over the years various researchers have described up to 80 different species—but many of these were incorrectly-described juvenile birds (a common problem in zoology and especially paleontology, e.g. dinosaurs). Currently most taxonomists argue for 13–24 species, across four genera: the great albatrosses (Diomedea spp.), the North Pacific albatrosses (Phoebastria spp.), the mollymawks (Thalassarche spp.), and the sooty albatrosses (Phoebetria spp.). So the ‘kind’ is probably at least as broad as the albatross family (Diomedeidae).
And it’s possible that the albatross kind might stretch beyond the family to include petrels too, i.e. as broad as the order Procellariiformes (the ‘tube-nosed’ seabirds). The giant petrels (Macronectes spp.) in particular show many similarities with albatrosses, e.g. heavy bodies; long, narrow wings with an in-flight shoulder-lock system enabling them to spend extended periods at sea performing dynamic soaring; and webbed feet. (And, when the wind isn’t strong enough to lift straight into the air, they exhibit the same lumbering take-off with legs and feet furiously pattering across the surface of the water—petrel actually means ‘Little Peter’, in reference apparently to the Apostle’s experience of walking on water (Matthew 14:28–30).) All Procellariiformes, including albatrosses and petrels, have distinctive nasal tubes (nostrils) running along their bill, but whereas the albatrosses have one on each side, petrels have fused tubular nostrils on the top of the bill.
Given that representatives of the albatross kind today can spend long periods (years, even) at sea without needing to visit land, why would albatrosses have needed to be on the Ark at all? A possible clue is in Genesis 8:1, where after 150 days of inundation, “God made a wind blow over the earth”. If this can be taken to imply that before then, i.e. for the first five months of the Flood, there was little or no wind, dynamic soaring would have been impossible. But in any case, albatrosses today survive those long stretches at sea by feeding on squid and fish which they search for in clear blue oceanic waters; not the doubtlessly muddy, debris-strewn and often violent Floodwaters. Genesis 7:23 in context makes it clear, concerning all the kinds that were taken on board the Ark, that none of their representatives outside were left alive after those first five months had passed (Genesis 7:14). Only Noah was left, and those with him in the Ark—including a pair of the albatross kind, from which are descended all the albatrosses we see today.
References and notes
- Johnston, I., How the unflappable albatross can travel 10,000 miles in a single journey, independent.co.uk, 17 November 2013. Return to text.
- Sachs, G., and 7 others, Flying at no mechanical energy cost: Disclosing the secret of wandering albatrosses, PLOS One 7(9):e41449, 2012 | doi:10.1371/journal.pone.0041449. Return to text.
- I.e. an in-flight heart rate of about 65–80 beats per minute, compared to 65 b.p.m. at rest, and a high of 230 b.p.m. when walking on land or taking off (from land or sea). Weimerskirch, H., and 4 others, Fast and fuel efficient? Optimal use of wind by flying albatrosses, Proc. R. Soc. Lond. B 267(1455):1869–1874, 2000 | doi:10.1098/rspb.2000.1223. Return to text.
- Fowler, C., Flying without flapping: The wandering albatross and the mechanics of dynamic soaring, blogs.bu.edu, 17 November 2012. Return to text.
- Traugott, J., Nesterova, A., and Sachs, G., The nearly effortless flight of the albatross: Measuring and modeling the bird’s aerial behavior could inspire new drone designs, spectrum.ieee.org, 28 June 2013. Return to text.
- Engineers identify key to albatross’ marathon flight: Flying in shallow arcs helps birds stay aloft with less effort, sciencedaily.com, 11 October 2017. Return to text.
- Pennycuick, C.J., Gust soaring as a basis for the flight of petrels and albatrosses (Procellariiformes), Avian Science 2:1–12, 2002. Return to text.
- See Chapter 4: Flight, pp. 63–82, in Sarfati, J., By Design: Evidence for nature’s Intelligent Designer—the God of the Bible, Creation Book Publishers, Atlanta, Georgia, USA, 2008. Return to text.