Seabirds - Future in the Wind

Essay by Cheryl Lyn Dybas

To understand the shore, it is not enough to catalogue its life.  Understanding comes only when we can sense the long rhythms of earth and sea that sculptured its land forms and produced the rock and sand of which it is composed; when we can sense with the eye and ear of the mind the surge of life beating always at its shores—blindly, inexorably pressing for a foothold. ---Rachel Carson, The Edge of the Sea

  SEABIRD POPULATIONS WITH A MORE THAN 50 PERCENT DECLINE over the last 25 years include the common gull, lesser black-backed gull and Atlantic puffin in the North Sea and Skagerrak; great cormorant, common eider, black-legged kittiwake and common guillemot in the Norwegian Sea.

BLINDLY pressing for a foothold is exactly what Brian Benedict and I are doing on this foggy afternoon, 26 miles off the coast of Maine.  Benedict is director of the Maine Coastal Islands National Wildlife Refuge, 52 islands scattered across the blue-black frigid waters of the northern Gulf of Maine.  On a map of the gulf, which extends from the crooked arm of Cape Cod to the outstretched hand of Nova Scotia’s Cape Sable, the islands look like skipped stones that somehow came to rest atop the waves.

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     But these rocks are far from smooth.  They stand like sentinels, their craggy granite faces inviting—if you’re a seabird.  For hundreds upon hundreds of Atlantic puffins, guillemots, razorbills and other birds of the open ocean, the welcome mat is out.  The birds spend their summers on the islands, raising the next generation there.  Publicly-owned islands like Matinicus Rock support more than half the global nesting population of 16 ocean bird species, according to the report The State of the Birds: Report on Public Lands and Waters.  

     On this unseasonably cool, 10oC June day, Benedict has anchored the refuge’s 8.5-metre research vessel just off Matinicus Rock.  We bob in the swells.  “You need a floatcoat for the next step,” says Benedict.  A floatcoat is a long-sleeved life jacket padded with insulating fabric.  “It will keep you alive for a while in this cold ocean,” Benedict explains, “and in the very unlikely event of a water landing—off the side of the boat.”  Ungainly as loons taking flight, we clamber into a small zodiac that ferries us the last few yards to shore.  I look straight up a granite cliff.  My gaze drifts foot by foot along an old wooden railway, its rockweed-covered planks stretching from the waterline to a lighthouse perched high above.  The railway once carried supplies up and down the steep edge.  Now as then, it’s also the only way on and off the island.

     “We’re stepping out of the boat and onto those slick cross-boards,” says Benedict, pointing to a section of railway that has almost disappeared under the swells.  “It’s slack tide, so we don’t have much time before it turns.  After that it’s impossible to get ashore.”  At low tide, exposed rocks near the railway’s end are too jagged for the zodiac to navigate.   The Gulf of Maine has the greatest vertical tidal range on the planet.  Tides in Canada’s Bay of Fundy in the far north are almost 56 feet, and have been measured at 71 feet.  The tidal range at Matinicus Rock is lower, but still high at a dozen or more feet. 

     I put a foot over the gunwale.  And begin sliding under the wood slats, my feet scrambling to find a toehold.  Just as I begin to crawl along the railway, making my way upward on all fours, a new threat looms, this time from above.  Common terns, thousands of which nest on the island, are no welcoming committee.  “They like to dive-bomb ‘intruders,’” warns Benedict, “so you might want to keep your head low.”  I wonder how 350 pairs of puffins, 375 pairs of razorbills, 1,800 pairs of Arctic and common terns, 1,000 pairs of laughing gulls and other birds survive on this 22-acre rock in the middle of nowhere. 

     Therein lies the island’s secret, says ornithologist Steve Kress of Cornell University.  “All these birds are here because of the lack of predators this far out to sea.  Along with fishing that’s usually fantastic in the surrounding waters, Matinicus Rock and islands like it is prime real estate for seabirds.”       Kress is widely known for his efforts to return Atlantic puffins to their former nesting sites on Maine islands.  Puffins and other seabirds once bred in huge colonies along the north Atlantic, or boreal, coast.  Early explorers penned accounts of the colonies’ astonishing sizes.

     The settlers who followed found it easy to figure out which islands had breeding seabirds.  Willing to scale the islands’ rocky walls, they collected eggs from nests and shot adult birds for food and fish bait.  As the millinery trade grew in the 18th century, the feathers of many seabirds became so valuable that whole colonies disappeared.  The one flightless seabird of the boreal coast, the great auk, had no defense against feather collectors and fishers.  By 1850, the last great auk had been killed.

     Seabirds were finally protected by the Migratory Bird Treaty Act of 1918.  Then populations on offshore islands began to recover, says Kress.  Even today, though, they’re shadows of what they once were.  To offer the birds a hand, Kress began to transplant puffins from Newfoundland’s Great Island to Eastern Egg Rock off Maine in 1973.  In 1981, puffins finally produced a chick on Eastern Egg.  “After more than 100 years of absence, puffins are again nesting there,” says Kress, whose Project Puffin is supported by the National Audubon Society.  Today Eastern Egg Rock has more than 170 pairs of puffins vying for space on seven acres.

     Kress’s team and that of the Maine Coastal Islands National Wildlife Refuge work together in a cooperative program to restore seabird populations on islands such as Matinicus Rock.  Their efforts led to research on when and where puffins forage for food. The scientists attached small temperature-depth recorders to metal leg bands on Matinicus Rock puffins, then recaptured the birds a week or two later to access the data.  It turned out that the puffins made almost 60% of their dives for fish between 4:00 a.m. and 8:00 a.m. and between 4:00 p.m. and 8:00 p.m. each day.  They averaged 276 dives per day—per puffin.  The dives were less than 15 metres deep, with the maximum dive 40.7 meters.  Average foraging site temperature was a chilly 11oC.

     Are they catching their usual fish, herring?  The answer, says Benedict, is not clear.  “Our field crews are seeing some birds--including terns, which we can easily watch on the islands--coming back with butterfish. When herring are hard to find, we start seeing butterfish.  Overall, they’re less nutritious.”

     Ocean warming and overfishing may be to blame. Biologists have measured the result in common and Arctic tern chicks; the growth of both species is slower, with smaller birds by fledging time. “We need to pay attention,” says Benedict. “Seabirds are important indicators of marine ecosystem health.”

     In good news from Matinicus Rock, researchers have found the first breeding common murres in Maine in more than 130 years. Last summer, four pairs of murres were seen incubating eggs under large rocks on the island. Closer to shore (and easier to land on) is Metinic, a 330-acre island that is five miles from the mainland. As of summer 2018, Metinic is home to some 982 common terns, 702 Arctic terns, 162 common eiders, 107 Leach’s storm petrels and 69 black guillemots, among other seabirds.

     With its crescent-shaped pebble beach and saltbox house above, Metinic has an uncanny resemblance to the island featured in the movie “Secret of Roan Inish,” filmed along the coast of Ireland.

     Whether off Ireland or Maine or other coasts, seabirds are facing similar challenges. Several seabird species in Norway, for example, have declined in recent years. The situation is especially concerning for black-legged kittiwakes, common guillemots, Brünnich’s guillemots and Atlantic puffins, according to scientists at the Norwegian Institute for Nature Research. Their report, The status and trends of seabirds breeding in Norway and Svalbard, documents large-scale changes in seabird numbers along the coast of Norway, including Svalbard.

     Seabird populations with a more than 50 percent decline over the last 25 years include the common gull, lesser black-backed gull and Atlantic puffin in the North Sea and Skagerrak; great cormorant, common eider, black-legged kittiwake and common guillemot in the Norwegian Sea; herring gull, great black-backed gull, black-legged kittiwake and Brünnich’s guillemot in the Barents Sea; northern fulmar and glaucous gull on Bjørnøya; and Brünnich’s guillemot in Svalbard.

     In Røst, the location of Norway’s largest Atlantic puffin colony, numbers have decreased from 1.3 million pairs to about 250 000 pairs over the last 28 years, according to Eirik Grønningsæter, a wildlife photographer who guides tours in the region. “Most breeding birds have abandoned their chicks this year,” Grønningsæter says. He glimpsed “two young puffins on the water - but sadly they were very small and probably will not make it. A premature exit from their nest is probably a result of starvation.”  The most likely reason for the declines, biologists believe, is ocean warming that has reduced the seabirds’ fish prey. As oceans heat up, cold-water fish are moving farther and farther north to chillier seas, leaving seabirds on-the-wing longer for harder-to-find meals.

     “Climate change, overharvesting of fish stocks, invasive species, pollution: all have affected marine life around the world,” says biological oceanographer Lew Incze of the University of Maine.  Researchers are conducting studies on Metinic Island that should help tease out the causes.  “One of the big projects here and on other Maine islands is productivity monitoring, or finding out how many chicks survive to fledging age,” says Benedict.  For tern chicks, that happens at about 15 days old. 

     To track productivity, explains Benedict as we carefully walk through a tern colony to count nests and eggs camouflaged against bare ground, “we fence off about ten percent of the nests in small plots.  Right now we have five plots, two for Arctic terns and three for common terns, with 59 nests packed into a very small space.”

     The number of terns in the plots correlates to the overall species ratio for the colony.  Data from productivity monitoring on Metinic, Matinicus Rock and islands like Petit Manan will be used to calculate survival and growth rates for the chicks.  On average, common terns have fledged 0.85 chicks per nest and Arctic terns 0.32 chicks per nest.

     Common terns have a shorter migration, allowing them to invest more energy in chick-rearing.  In contrast, Arctic terns are famous for their long journey; they fly from north Atlantic breeding grounds to the Antarctic and back again each year.  The 19,000-kilometre migration--each way--allows the birds to see two summers every year, and more daylight than any other creature on the planet. 

     Seabird biologists have long wanted to track Arctic tern migration from islands along the coast of Maine to wintering grounds in the Southern Hemisphere. In 2010, researchers deployed 30 geolocators on Arctic terns breeding on Metinic and on Eastern Egg Rock. Geolocators are small electronic devices that estimate the location of a bird based on the length of daylight and the time of sunrise and sunset. Prior to this tagging effort, which will continue through 2020, scientists could only guess where the birds traveled.

     At the end of the breeding season and the start of fall migration, all the tagged terns left the Gulf of Maine and headed toward northeastern Nova Scotia. Three birds flew south along the west coast of Africa, then to the Indian Ocean. Four birds went along the west coast of Africa to the east coast of South America. The remaining six birds headed south across the open Atlantic Ocean before spending the winter along the east coast of South America.

     “This study points to the importance of protecting terns and other seabirds over their entire world range, including their feeding areas at sea,” says Kress. “It shows that the Arctic tern belongs to both hemispheres, and that the birds’ flyway is the full Atlantic Ocean.” 

     On Metinic, as Benedict ducks another tern bold enough to graze his head, I face into the winds that swirl around the island.  What would it be like, I wonder, to flap seabird wings and lift off into the mist, feathers touched with sea spray, then follow an ancient path across the waves to piscine treasure? 

     To see with the eye and ear of the mind, the surge of life where wind and wave and fish meet?  For us humans, it is a place that, at least for now, remains over the far horizon.

Ocean Geographic Field Editor Cheryl Lyn Dybas, a Fellow of the International League of Conservation Writers, is an award-winning science journalist and a marine ecologist.

Essay by Cheryl Lyn Dybas. Photographs by Michael AW ( OG 48) 

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