Solving the Piping Plover Puzzle
Piping plovers are famous summer residents of beaches and lakeshores--the most adorable argument against development and reckless recreation. Yet where many spend the winter has long been a mystery. Until now.
Back at the skiff, we set off again for another site. When we get there everyone jumps into the shallow water and wades toward a sandbar, scopes over their shoulders. Here it takes an hour to count plovers, and the tally is better than expected: 81 birds in all. Although it is only mid-afternoon, by the time the biologists return to the skiff we must head back or risk getting stranded here as the tide recedes.
After dinner back on Andros that evening, Golder places a satellite map of the Joulters on the table and marks GPS readings for the latitude and longitude of each cay they visited. As he reviews the list of birds, he keeps a running count that totals 326 piping plovers--more than three times the number they spotted last year. It is becoming increasingly clear that any successful conservation strategy for ensuring a healthy piping plover population must include protecting the Bahamian islands and cays they frequent from a wide range of threats, including development, the spread of invasive plants, and sand-mining operations.
Just 10 years ago no one knew that the Bahamas were so important to plovers. A 2001 census recorded only 35 of them in the entire chain. The census, started 10 years earlier by Sue Haig, was part of a USGS-coordinated effort to count the entire U.S. piping plover population every five years. More than a thousand participants counted the birds on their breeding territories, then a few months later spread out across the core of the plover's known wintering area to do the same--walking the beaches from North Carolina south along Atlantic shores and across the entire U.S. Gulf Coast. But winter surveyors found fewer than half the plovers tallied during the summer censuses--a serious challenge if you're trying to conserve the species. Knowing what's going on mostly in the breeding grounds is "like being blind in one eye," says Haig. "If you don't know the full story, you're going to make mistakes in the measures you'd take to protect the birds."
Haig and others suspected that large numbers might remain hidden in the Bahamas, and in 2006 Sidney Maddock, working for Audubon North Carolina, along with local volunteers, mostly from the Ornithology Group of the Bahamas National Trust, set out to cover more of the region. The survey of 66 sites delivered 417 piping plovers. Encouraged by the results, in 2011 the USGS increased coverage of the Bahamas with the assistance of biologists from there, as well as the United States and Canada, and the total rose to 1,066 birds. If the results of recent banding studies (see map, page 51)--under the direction of Cheri Gratto-Trevor of Environment Canada--are any indication, almost all of the plovers that winter in the Bahamas hail from the Atlantic Coast, and the 1,066 represent nearly one-third of the coast's breeding population.
Understanding this link is one thing; seeing it is another. The mysteries and marvelous feat of migration quickly become personal. So it was that six months before my trip to Andros I stood on a Long Island beach, my binoculars trained on a nesting plover 75 yards away. I squinted, looking for the bands that would indicate this was a Bahamas bird.
Kerri Dikun, coordinator of Long Island bird conservation for Audubon New York, stood next to me with a spotting scope. She had spent much of her summer monitoring 36 plovers at six different nest sites, including two banded Bahamas birds. Dikun is one of a small army of hundreds of people from 70-plus government and nongovernment agencies and organizations that monitor and protect the breeding plovers each summer.
Up and down the Atlantic Coast, rapid housing development on beachfront property and increased recreational use of beaches beginning in the boom years after World War II have continued to encroach upon the plover's nesting sites, in the area above the high-tide line. But the program to protect nesting sites, begun in 1986 when the United States placed the piping plover on the endangered species list, has proved successful. Between 1986 and 2010 the Atlantic Coast population alone more than doubled, to 1,782 pairs, and the total population has reached roughly 8,000, a bit closer to the species' historical population, estimated to be in the tens of thousands.
And yet 8,000 birds hardly ensures the species' future. One need only recall the fate of another shorebird, the Eskimo curlew, whose populations plummeted in a matter of decades in the 19th century, from hundreds of thousands to a few dozen individuals. Indiscriminate hunting was not the only factor; loss of the grassland habitat the birds depended on during migration was another. Today the Eskimo curlew appears to exist in name only.
On my first day on Long Island, before looking for banded birds, Dikun was slated to check on some piping plover chicks that were close to fledging at Orient Beach State Park, on the northeast tip of Long Island. We drove two hours, then walked another two hours to the end of a peninsula, where a pair of the birds had moved their chicks some days earlier, far away from beachgoers. Dikun, a 28-year-old brunette, her hair pulled into a tight bun to keep it off her neck on the sweltering July day, raised her binoculars and scanned the beach ahead of us, watching for any movement among the stones and sand heaped up by waves.