by Carl Safina
The subarctic in early March isn’t exactly the same sunny, warm climate that Amelia left at her nest. It is gales and sleet, freezing and dark and terrible. Few marine animals can withstand both extremes. But albatrosses do. How does she handle that kind of climate shift? Dave Anderson, looking at the satellite track Amelia is sending to his lab, has this answer: “I don’t know. I don’t have any idea how an albatross can do that. Most animals would freak out. This bird in a few days went from basically a tropical climate to basically an arctic climate. I don’t know how it can handle such abrupt change. When I first saw what this bird is doing—it was quite a moment.”
Albatrosses belong in cold waters like these, along these fronts and gradients, in this chilly air, where the wind seems to have an appetite of its own. Here in the chill, Amelia feels fully at home and comfortable for the first time since she went to Tern Island months ago to start the breeding season.
Amelia works this zone four days, sometimes in the flowing front, then drifting beyond, then back along the front. She searches for concentrated scents, sharp sea-color changes, and other signs of concentrated life. She moves west into the current for 225 miles one day, 250 the next.
Then she finds the life she’s looking for. And the death that accompanies it.
The frontal boundary is distinct here, the sea-surface temperature gradient sharp. Certain patches along this front suddenly seem almost to be squirting with squid. This is part of the area, in fact, where during the 1980s and into the 90S the squid boats of Taiwan, Japan, and Korea set tens of thousands of miles of drift nets each night. Pacific albatrosses had been recovering from the feather hunting of the early 1900s and the disruption of World War II and Cold War military presences at major breeding sites when drift nets began infesting their foraging areas. With something like forty thousand miles of nylon webbing spun into the blue Pacific each night, hungry albatrosses found a lot of dead fish and squid tangled in those nets. But the drift nets served dangerous dinners. Before the United Nations finally banned them in the early 1990s (they’d originally promoted the same nets), each year roughly twenty-two thousand Hawaiian albatrosses attempting to wine and dine got wound and drowned. Their populations again declined. Drift-net crews sometimes fashioned earrings from albatross leg bands. Those nets also killed much higher numbers of other seabirds. The estimated kill of Sooty Shearwaters ran to half a million annually. for over a decade. Tens of thousands of dolphins, whales, and seals also drowned, and tens of millions of unwanted fish died in the nets and were shoveled overboard. The level of collateral mortality doesn’t begin to speak to the millions and millions of tunas, marlins, Swordfish, salmon, and Neon Flying Squid that the nets removed from the oceans.
Amelia is now a recipient of the United Nations’ belated wisdom and the banned boats’ departure. Not only did so many albatrosses die annually in those nets, but now more squid again slide through the waters here for Amelia, and for the famished, feathered nations whose culinary traditions were set long before the seas were etched by a million wakes.
Amelia is also benefiting from the predations of pods of dolphins. From time to time they stage well-coordinated attacks, streaming up under the squid from below in tight, streaking packs, sending them fleeing into the atmosphere. Packs of squid are jetting around here and there, appearing and disappearing, everywhere and nowhere. Stimulated by the activity, aware of the opportunities, keenly alert, Amelia wheels in among the streaking mammals and swift fleets of fleeing squid. She lands and takes off repeatedly, trying to keep up with the speeding dolphins. She splashes in among their bubble trails and deep boils and the spraying squid, paddling around excitedly, sometimes clumsily, trying to exploit the possibilities that keep coming and going around her. Her snapping bill mostly misses, registering a loud empty clack. But once, there’s the satisfying feel and heft of writhing flesh impaled with the nail of her bill tip. The squid wraps its resisting arms around her bill, and she shakes and worries the life from it. It goes coolly into her belly, and for a while it squirms a little as it warms. She likes the feeling of food inside.
But the main thing, for Amelia, is that the squid are here spawning. And after they spawn they die. And after they die, many float to the surface. And beautiful fresh, floating squid are what makes this trek north worth all the effort. She begins loading up on nice, ice-cold squid. She’s finally putting back a little weight and storing extra food.
Here in this rich, cold water, Amelia has company: many other Laysan Albatrosses, a few Black-footed Albatrosses (most of them are much farther east, nearer the continental coast), and very occasionally a rare Short-tailed Albatross from Japan. Amelia doesn’t pay much attention to any of them—except when they’re zooming in on the same meal.
With her belly feeling full for the first time in weeks, Amelia sails west for a day or so, outside the current edge and into the 48° F (9° C) subarctic watermass, until she’s fourteen hundred miles from Tern Island. The seesaw between maternity and hunger tips again—and this time maternity easily wins. As if by magic, Amelia lights out on a heading that will take her directly home, and flies for another thirty-two hours, covering 560 miles in a straight line on a strong sidewind, crossing back into subtropical water. During a stormy, gusty, squally, rain-pelting night she drifts a hundred miles to the southwest. Then she streaks straight toward Tern Island again, this time aided by a strong tailwind from a fresh high-pressure weather front. She smells the air growing saltier and warmer as she bores back into tropical waters, back to the domain of terns and boobies and frigatebirds and tunas and tropicbirds. It’s all so different and it’s all so familiar. After another 730 nonstop miles and thirty hours of straight flying, she again crosses French Frigate Shoals’ thundering reef and lands clumsily on Tern Island. It is March 14. After sixteen days at sea, the ground seems oddly unyielding. She still feels as though her body is gliding with gusts and swaying to swells.
Amelia’s Travels February 26-March 14
On legs that have grown unaccustomed to supporting her weight, she waddles over and calls to a surprisingly large chick. “That you?” To which the chick immediately responds. “Me. Alive.” Amelia hasn’t seen her mate in weeks, but by the looks of the chick, Dad too has been faithful to his duties, working as hard as Amelia.
Amelia has just returned from a forty-two-hundred-mile odyssey, but does her chick appreciate it? Does she get a moment’s rest? Her chick is big enough now to be aggressive, and hasn’t been fed in about a week. He practically attacks Amelia, whining and battering her bill with his own hooked beak. This ritual stimulation makes her retch on cue. And the chick scissors his bill into her gullet to catch her presents. Amelia barfs a sizable whole squid and several meaty chunks in the first payload. This immediately goes a long way toward filling the chick, which suddenly pauses to swallow, mucusy strings of goo dangling from the corners of his mouth. Mmm.
No chick could ask for more. But this one does. In maternal devotion, Amelia pours her heart out. On Amelia’s next retch, the meal comes as liquefied high-calorie oil, stored from food she caught at the beginning of her journey. Oil squirts from her in a strong brown stream, as though from a pressurized hose. The chick takes all of it, reveling in the satisfaction of liquefaction. About a minute later Amelia leans forward again. Her babe sticks his bill way up into her gullet. Another stream of liquefied matter comes forward. The chick sits back, swallowing. Amelia resumes her upright position. The urgency seems gone; the chick seems finally satisfied. About a minute later, Amelia leans forward one more time. When she steps back, a gooey string stretches between her bill and the chick’s, then parts. The chick spends a few minutes wiping its bill in the sand. Then it dozes, a fat little child, healthy and vigorous, content as any youngster could ever be.
Her parental duties discharged, Amelia walks away. She surveys the noisy island, the birds of so many species crisscrossing overhead, the younger albatrosses courting and dancing with the passionate fervor of youth (and no adult re
sponsibilities). Amelia has seen it all before. She’s a hardworking mom, and the youthful crowd holds no fascination for her. Amelia registers only that her chick is alive and vigorous, and this means one thing: it will need more food. In a mere ten minutes she’s on the runway, good for takeoff.
SEABIRDS ARE THE AVIAN WORLD’S undisputed champions of long-range navigation, but nobody knows for sure how they navigate. Unlike land birds, seabirds remain oriented over open ocean, where—to us at least—there are no landmarks; and they do so over extreme great distances. Behold one of Amelia’s lovely smaller cousins, the Sooty Shearwater. Sooties are long-distance travelers in the Atlantic, but New Zealand’s Sooty Shearwaters are most amazing. After being abandoned by their parents a month before they can fly, the young ones make a fifteen-thousand-mile migration—perhaps the longest annual migration in the world—on their first attempt. They head out into the Pacific toward Japan, spend the summer off Alaska and in the Bering Sea, then go down the west coast of North America. Where the ocean is widest, they fly west across the entire Pacific and travel back to New Zealand, to the same island they left. They make that long migration, including its complex directional changes and equator crossings, without any contact with older, experienced birds. If you’re following your parents, you don’t really need a good navigational system. But if you have to go it alone, like a young Sooty Shearwater, the demands are much, much higher.
We know from experiments that migratory songbirds have two compasses: magnetic and celestial. Seabirds probably do too, but they have hardly been studied because of the difficulties both of keeping them in captivity and of performing good experiments in the wild. Much of what has been learned about the orientation capabilities of songbirds probably applies to seabirds, though. The celestial and magnetic compasses are not as you would imagine. For their celestial compass, young birds are born only with instructions to look for rotating light dots in the night sky and to orient their first migration away from the center of rotation—away from the pole. In other words, they start their migration using just the rotational point of the heavens over Earth’s poles. During that first migration, though, they learn star constellations. After they’ve learned the star map, when the rotational point is covered by clouds they need only to see a few stars and can extrapolate where the rotational point is.
A bird’s magnetic compass is even more counterintuitive. After decades of studying navigation, we still don’t understand the mechanism by which birds perceive and orient to magnetic fields. We know that they do so, because experiments clearly demonstrate that changing the magnetic field in a laboratory changes the orientation activity of wild-caught birds during the migration season. But we haven’t found a magnetic sensory organ. Many kinds of animals have magnetite in their bodies, including birds. Some fishes have magnetite in their nasal region, in close association with nerves and in proximity to the brain, suggesting strongly that these fish can navigate with a magnetic-polarity compass like the ones people use on boats and in airplanes. But in birds magnetite is usually found in bones, not consistently in association with nervous tissue or the brain, as you’d expect if they are using it for navigation. Nonmigratory birds also have magnetite, suggesting it’s not there for navigation. Further, birds have an inclination compass, not a polarity compass. That means they can’t distinguish between north and south across the equator. Their magnetic-orientation ability allows them to understand only whether they are headed toward the equator or toward the pole. Near the equator, where our mechanical magnetic-polarity compasses work perfectly, a bird is unable to orient magnetically: it can’t sense the polarity of the magnetic field. (Birds migrating across the equator probably switch to celestial navigation, using the sun and stars until they can get magnetically oriented again.) If they were using the magnetite for navigating, they should have a polarity compass like the mechanical compasses we use, and they should not have the inclination compass they actually have. So why do they have magnetite at all? Dr. Henrik Mouritsen, who has worked on Waved (Galápagos) Albatross navigation with Dave Anderson, believes that birds use magnetite simply to get rid of excess iron; it has nothing to do with navigating or orienting.
Dr. Mouritsen has another idea that he is testing. One evening at Dave’s field camp on the Galapagos island of Española, while an albatross that had just returned from a foraging trip sat under our table with its chick, Dr. Mouritsen explained to us: “A very fascinating thing about birds’ magnetic orientation is that they can’t do it in total darkness. In white light as faint as starlight, but with no view of stars, they move in the right direction using purely magnetic cues. Now the thing is: if you then test them under green light, they’re fine. If you do it in blue light, they’re fine. If you give them red light, they’re equally active—but unoriented. They see—they’re jumping around—but they cannot orient to a magnetic field in red light.” Drawing on these clues, Dr. Mouritsen has theoretically worked out a mechanism by which birds might see Earth’s magnetic field. He says, “The theorized visual mechanism could not give information on north and south, only on equator versus pole—exactly the information the birds are actually somehow acquiring.” If, after several years of experimentation, he turns out to be right, his discovery of a mechanism by which birds see magnetic fields could make him famous. Meanwhile, the mystery remains. We know that seabirds use the sun and stars, that they have a magnetic compass of some kind, and that they rely on their unusually sensitive sense of smell. But nobody really understands how seabirds accomplish their great feats of navigational magic. Yet navigate they surely do, over vast, seemingly bleak distances.
ALBATROSSES FLY SO FAR for one reason: to get to where food is. But another way of looking at it is that they fly so far because they have no way of getting their chicks closer to the better foraging zones. These albatrosses’ tropical breeding sites, so far from abundant food, are just an accident of island formation. If suitable islands existed closer to these food-filled frontal zones, they would be graced by nesting albatrosses. The Aleutians are too ironclad with cold during late fall and winter and early spring, while the birds are laying, incubating, and hatching fragile chicks. No islands lie closer to the food and also have eight months of weather eggs and chicks can survive in. And weather aside, most islands closer to the food in this ocean—off Alaska and British Columbia—have things like eagles, bears, and otters. You don’t leave a fattened chick alone on places like that and expect to see it again. So there seems no suitable real estate that would afford a shorter commute.
It seems hardly to matter. Albatrosses are well forged to endure long trips. Their high-efficiency long-distance dynamic soaring, ability to store liquefied food as high-energy oil for fueling, and their chicks’ ability to survive prolonged fasting all indicate long accommodation to tough conditions necessitating extreme travel. For albatrosses, sparse times and long trips are nothing new. Albatrosses wield distance as their weapon against deprivation.
Albatross travels are everywhere prodigious. Light-mantled Sooty Albatrosses forage an average of a thousand miles from their nests. One Wandering Albatross with a chick in the nest logged a jaw-dropping single round-trip of nine thousand miles between feedings.
After breeding, unchained from the need to feed a chick, albatrosses begin roaming enormously. On July 2, 1992, one Wanderer that had lost its chick left the subantarctic island of South Georgia (the large, glacier-crusted island twelve hundred miles east of the southern tip of South America) for the edge of the continental shelf off central Argentina. It then flew east, crossing the Atlantic to spend nine days foraging in waters well off South Africa. From there the bird lit east again, and by August 9, when its transmitter’s battery failed, it was within a few days’ travel of Australia. In under five weeks, it had traveled fifteen thousand miles from its nest.
Northern Royal, Chatham, and Buller’s Albatrosses from New Zealand cross the entire South Pacific in as little as seven to ten days to spend their nonbreeding time foraging i
n the Humboldt Current off Chile and Peru. Some New Zealand birds, including the Northern Royal Albatross, pass the tip of South America and continue through the Drake Passage into the Atlantic, where they forage over the Patagonian Shelf east of Argentina. (One arrived off the Falkland Islands, over eight thousand miles away, eight days after leaving New Zealand.) Some Northern Royals continue to the east, completing a circumpolar route.
Albatrosses making global circumnavigations must share Albert Einstein’s view of the universe: that if you go far enough in a straight line you will eventually come back to the place you started. Or perhaps they are inspired by T. S. Eliot:
We shall not cease from exploration
And the end of all our exploring
Will be to arrive where we started
And know the place for the first time.
Check the odometer of an albatross half a century old: Albatrosses spend 95 percent of their lives at sea. They fly up to 90 percent of the time they’re over water, and the smallest fraction of time any tracked albatross spent flying was 60 percent. Their slowest average flying speed is about fifteen miles an hour. So here’s some conservative arithmetic: 95 percent of 365 days is 347 days; over fifty years, that’s 17,350 days at sea. Sixty percent of each day is 14.4 hours; flying at fifteen miles per hour gives 216 miles for each day at sea. That yields an extraordinary low-end estimate: 3,747,600 miles.
