Royal terns are increasingly hard to find in the Chesapeake, because the sandy islands they need to live are vanishing rapidly in the Bay. Photo credit Getty Images
In Search of the Chesapeake's Vanishing Royalty
By Tom Pelton
Published in the Fall 2010 issue of Save The Bay magazine
It was a hot, windy morning and I was pounding through the choppy waves of the Chesapeake Bay, on a quest to find the inhabitants of a sinking island.
I was in a motorboat driven by John Rodenhausen, Discovery Program Manager for the Chesapeake Bay Foundation (CBF), who captains educational expeditions on the Bay.
We cruised past a spit of land south of Crisfield, Maryland, where the collapsing brick ruins of a fish oil factory rise up from sandy banks. Then we sliced left, across a marshland, down a narrow creek, and into the maze of reeds and waterways that is the Cedar Island Wildlife Management Area.
"We're heading south," Rodenhausen said, "in search of the elusive royal tern."
The birds we were looking for are increasingly hard to find in the Chesapeake, because they nest only on isolated, sandy islands.
Photo by Bill Portlock/CBF Staff
Royal Tern Facts
DESCRIPTION: Beach-dwelling fishing bird with orange beak, short forked tail, white and gray feathers, and black crown. After courtship, the crown thins and lightens, looking like a bald spot.
SIZE: 18 to 20 inches in length, with a wingspan of 49 to 53 inches.
RANGE: Coasts of North and South America
DIET: Fish and shrimp
NESTS: In large colonies on sandy, isolated islands
SOURCE: THE CORNELL LAB OF ORNITHOLOGY
Royal terns—gull-sized fishing birds with majestic black crowns and orange beaks—are hunters that hover over the water and then plunge down violently to catch their prey, earning the nicknames "face smashers." They require isolation to survive. Each female lays one egg on sandy beaches, right out in the open, making them vulnerable to raccoons, dogs, or other predators.
Unfortunately, the sandy islands they need to live are vanishing rapidly in the Chesapeake Bay. A combination of rising sea levels, caused by global warming, and naturally settling land has meant that more than 500 Bay islands have sunk beneath the waves over the last three centuries, according to author William B. Cronin's, The Disappearing Islands of the Chesapeake.
Some of these submerged places, like Holland and Barren islands, until the early 20th century, held the Victorian homes, churches, and graveyards of oystermen. Others may have been hideouts for pirates and schemers—folks who wanted isolation so they could hunt illegally, gamble, and launch bizarre schemes like breeding black cats for profit.
Now their low-lying haunts—and the homes of royal terns—are being swept away faster than almost anywhere else on earth.
Under a bright blue sky streaked with clouds, we motored into the Fox Island chain, where CBF runs educational programs out of a former hunting lodge built on pilings.
Past the lodge, we saw a sandy flat with scruffy bushes rising up out of the waves. We anchored the boat and climbed ashore onto Clump Island, a small fragment in the Fox Island group.
Hundreds of royal terns crowded in the grass, their brown speckled eggs laying everywhere on the ground, like they had been spread for an Easter egg hunt. The crowned birds stood guard, screaming and scolding us as we approached their treasures.
The birds acted like they were willing to fight to defend their last home. We had heard that this corner of the Fox Island chain was the last place in the Chesapeake Bay where royal terns nest. Rodenhausen said he had watched the islands here dwindle to almost nothing as he visited on educational trips over the years.
"Fox Island was hundreds of acres, and now we're reduced to less than 100," Rodenhausen said. "The islands have shrunk dramatically due to erosion. There isn't a physical barrier to stop the waves from eroding the shores. So the sand and the mud give way to the power of the passing storms and everyday wave action."
As the island habitat has sunk, so has the royal tern populations in the Bay. They declined by about a third between the 1970s and last decade, falling from 4,734 breeding pairs in 1977 to 3,332 pairs in 2003, according to a 2007 study called "Colonial-nesting Seabirds in the Chesapeake Bay Region," published in the journal Waterbirds.
Rodenhausen said he doesn't know what will happen to these birds when erosion finally swallows this sandy sliver where they breed. "I'm concerned about where they are going to go, because they are going to run out of islands, soon," he said.
When we returned to land, I called David Brinker, an ecologist with the Maryland Department of Natural Resources, who said it is likely that terns will continue to vanish from the Bay as their islands are consumed.
"They'll go looking for another sandy little island," Brinker said. "Maybe they'll find it, and maybe they won't."
However, Brinker noted that some terns are adapting to the loss of their natural habitat by trying to nest elsewhere.
A second colony recently made a home at the southern end of the Chesapeake Bay atop the gravelly roof of a cement structure that is part of the Hampton Roads Bridge- Tunnel, according to Ruth Boettcher, a wildlife biologist at the Virginia Department of Game and Inland Fisheries.
It's not exactly a natural home for their royal highnesses. But it is an island, of sorts. And it is isolated from most predators—except one.
Boetticher explained that, beyond the disappearance of islands, royal terns also face another danger—increasing attacks from the rising population of herring gulls. Often called "seagulls," herring gulls, with their white heads and black wingtips, did not historically nest in the Chesapeake Bay region, but rather in the northeastern states and Canada.
But herring gulls have been multiplying and moving south as development has brought in more trash, which gulls love to eat, said John S. Weske, a former staff biologist for the U.S. Fish and Wildlife Service. In that sense, he said, herring gulls are like rats or squirrels—animals that thrive amid human development (unlike royal terns, which need isolation).
"Herring gulls have come down from the north and they are predatory toward the young royal terns," Weske said. "We have built all these wonderful feeding stations for gulls. They are called dumps."
So in my quest to find a sinking island, I found a truth that made my heart sink. Our pollution is pushing this royalty out of the Chesapeake, both in our carbon dioxide that is driving up water levels, and in our garbage, which is drawing in more gulls. We need to make a U-turn in how we live for the sake of the royal terns.