Osprey Comet reaches winter destination
This fall, thousands of spectators along the Atlantic Seaboard were glued to their computer screens watching a remarkable event: the migration of five juvenile ospreys from their home nests to winter destinations in Central and South America.
Each bird was fitted with a miniature satellite transmitter by Dr. Rob Bierregaard of the University of North Carolina, Charlotte, who has studied ospreys and other raptors for more than 30 years. The birds' positions, are downloaded by ARGOS and plotted on maps, enabling anyone with Internet access to track their migration via the World Wide Web.
For the second consecutive year, the Conanicut Island Raptor Project installed a transmitter on juvenile osprey from Jamestown's Marsh Meadows nest at the Great Creek. This male was dubbed Comet in honor of Metacomet, sachem of the Wampanoag tribe. This year's study was funded in part a grant from the Audubon Society of Rhode Island. Elsewhere, transmitters were installed on four other juveniles from Delaware and Martha's Vineyard. Students from Lawn Avenue School cheered as Comet, a four-month-old hatchling, grabbed the early lead when he turned up in Cape May, N.J., on Sept. 7. From there, he skirted the southeast coastline to Florida in a predictable path, staying over land as much as possible.
The migrations of more than 150 adult ospreys have been documented in North America, giving us a detailed understanding of how and when adult ospreys migrate and the routes they take. Far less is known about juveniles, which is why CIRP's studies are signifi- cant. Nearly all East Coast adult birds go through Florida to Cuba to Hispaniola and on to South America. Some New England birds think Florida or the Caribbean islands are far enough south. Some Florida adults migrate deep into South America, while other Florida adults stick around for the winter. Adult females migrate about a month before males, and adults of both sexes are faithful to their chosen wintering grounds.
Because young ospreys have a high mortality rate and satellite transmitters are very expensive, only a handful of first-year ospreys have been tagged. Since 2004, Rob Bierregaard has concentrated on tracking juvenile birds to better understand their migration. When do they go south? How do they find a reliable wintering area? Do they spend time exploring or choose the first good spot they find? We know from traditional banding studies that they stay on the wintering grounds for at least a year and a half. Do they all return in their second year? Do they go all the way home on their first return? Will siblings with the same parents, born in the same nest but a year or more apart, choose the same wintering area?
Tracking Conanicus (2005) and his brother Comet (2006) promised to shed light on these questions. Conanicus had coast-hopped to Florida and headed to Cuba, spending the next year in Zapata Swamp on Cuba's southwest coast. He has shown no inclination to leave that rich feeding ground that is home to hundreds of ospreys. Would Comet follow Conanicus's path?
That appeared to be the consensus of those who attended Hey Day at the Dutra Farm in mid-September. Dozens of visitors paid a dollar for a pushpin and a chance to guess where on the map Comet would winter. Comet was then in Cuba not far from his brother Conanicus. Nine out of 10 contestants wagered he would remain there. But Comet had other ideas. That night he took off from Cuba and flew south into the open Caribbean to Pedro Cays, southeast of Jamaica. Only 12 days out of Jamestown, he had logged 2,250 miles.
The next 24 hours would be the most perilous for the four-monthold osprey - and a cliffhanger for those tracking his progress on the Web. Rather than following the "Osprey Highway" and islandhopping southeast among the Greater Antilles, Comet headed due south to Panama, crossing 560 miles of open sea in 24 hours without stopping. He cruised southeast along the Gulf of Panama, becoming only the second East-Coast osprey Bierregaard has tracked to reach the Pacific Ocean. From there, Comet headed southeast to the Choco region west of the Andes and joined the flyway taken by many ospreys from the Midwest. By mid-October he had settled down in the Cordilleira Occidental, on the western slope of the Andes. Although far from the sea, this is one of the wettest corners of the planet, receiving up to 480 inches of rain annually. Ospreys feed exclusively on fish and do not discriminate between fresh- and saltwater fish as long as they are plentiful.
On Comet's first migration, he covered an impressive 3,000 miles in 21 days. He pushed deeper into the South American wilderness than anyone expected. Anyone, that is, except Jamestown's Mary Hutchinson. At Hey Day, Mary had stuck her pushpin in Cartagena, Colombia, at the bottom edge of the map. Comet exceeded her prediction by 250 miles. Who'd have thought that a four-monthold fledgling osprey from Jamestown would fly beyond the boundaries of the osprey tracking map to become a local legend?
The Conanicut Island Raptor Project is a non-profit educational program sponsored by Jamestown Education Foundation, Audubon Society of Rhode Island, the Jamestown Conservation Commission, the Conanicut Island Land Trust, RI Turnpike & Bridge Authority, the town of Jamestown, Jamestown School, and Rob Bierregaard of UNC Charlotte. To learn more about CIRP's osprey tracking program and live Web camera at Great Creek, visit www.conanicutraptors. com and click on "Osprey Tracking." Sequential maps will lead to a Google Earth satellite photograph of each bird's final destination.
Funding is urgently needed to pay for satellite download time necessary to track birds and for new nesting platforms to ensure returning ospreys have a place to nest in Jamestown. Donations are fully tax deductible and may be made by check to Jamestown Education Foundation, with "Osprey Project" on the memo line. Mail checks to Jamestown Education Foundation, 77 Narragansett Ave., Jamestown, RI 02835. For more information, contact Chris Powell, 423-1492.