Coley the Osprey Returns to Jamaica Bay

Kirsten Luce for The New York Times Coley and his mate, on their nesting perch in Jamaica Bay.

A fish hawk named Coley reunited with his mate off the coast of Queens this week on the first day of spring. His spiky brown crest was slightly ruffled, but otherwise, he seemed surprisingly poised after completing his northern migration.

He did not flinch at the din of a Delta jet approaching the nearby runway at Kennedy International Airport.

Wherever that plane was coming from, its trip had undoubtedly taken less time than Coley’s.

Over 15 days, he had clocked about 2,600 miles, starting from Ciénaga Pajaral, or Bird Marsh, on the northern tip of Colombia.

On Wednesday evening, a ranger at the Jamaica Bay Wildlife Refuge spotted the female eating a fish on the nest, perhaps gifted by Coley as an act of commitment.

Coley is offering researchers an extraordinary view of the hunting and flying patterns of ospreys, fish-eating raptors with five-foot wingspans.

As part of a two-year project spearheaded by the National Parks of New York Harbor Conservancy, the three-and-a-half-pound brown bird with a white breast was equipped with a harness attached to a solar-powered GPS device. It was about the size of small matchbox, with a 10-inch antenna sticking out the back.

Uli Seit for The New York Times Coley, newly outfitted with a GPS device, in May 2012.

For 16 hours a day, it records the location, altitude, speed and direction of the bird.

“These birds know where they are going and do not waste any time getting there,” said Bob Kennedy, an osprey expert and science adviser for the harbor parks, who outfitted Coley with his one-ounce backpack last May.

Dr. Kennedy, whose chronicle of Coley’s adventure is at www.jamaicabayosprey.org, said he believed that the bird had made the journey before, but many mysteries remain.

“We know a whole lot more about migration than we do 50 years ago,” he said. But how they navigate - using land features, the Earth’s magnetic force, celestial and solar cues, or a combination of these methods - is not exactly clear.

“Prior migration experience probably plays an important role as well,” he added.

Coleman P. Burke, a founding board member of the harbor conservancy who invested $25,000 in the endeavor, about half of its total cost, has been anxiously monitoring his namesake’s progress.

“He’s facing headwinds and bad weather,” Mr. Burke said. “This is not a simple drill.”

View Coley the Osprey’s Complete Migration North, 2013-03-05 to 2013-03-20 in a larger map

On March 8, Coley completed the most challenging leg of the trip, 440 miles from La Guajira Peninsula in Colombia to the extreme southwest coast of Haiti, entirely over water. Counting the miles he flew to reach the Colombian coast and the distance he flew after reaching Haiti, he logged over 530 miles of nonstop flying in 34 hours.

Osprey have made a vigorous comeback in recent decades after the population was nearly decimated by the use of the pesticide DDT in the 1950s and ’60s.

Kirsten Luce for The New York Times The female osprey returned to the platform with additional nesting materials on Thursday.

Dave Taft, who is the National Park Service’s coordinator for the wildlife refuge, which is part of Gateway National Recreation Area, recalled when a breeding pair of osprey was a rare site.

Today, the refuge is home to about 15 man-made nesting platforms, with additional bird-created sites on channel buoys and telephone poles, a sign of the bay’s environmental health, Mr. Taft said. Last summer, about 25 baby osprey fledged successfully.

And when the adults return for mating season, “we’re so happy to see them,” he said. “But finally, we hope to answer the question, where do these birds go”

Because of a long breeding cycle, ospreys are among the first birds to migrate north for the season.

Now that Coley and his mate have reunited, they will reaffirm their bond with aerial courtship displays. They will bring offerings of fish and nesting materials to their aerie. If this pair reproduces successfully, they could be warming three or four eggs before mid-April.

For a moment, the nest - which is three feet tall, weighs over 100 pounds and was practically untouched by Hurricane Sandy - was empty on Thursday morning. While Coley explored the salt marsh cordgrass, his mate ventured out of sight, returning a few minutes later with a slim twig she then tucked into the pile.

“It’s dangerous to anthropomorphize,” said Mr. Taft, but he allowed that it was possible that the bonded pair was experiencing some sense of relief that they had made it back for another year in Jamaica Bay.

Google Earth via The Harbor Conservancy Coley’s route north, from Colombia to New York. Click to Enlarge

Coley by The Numbers: March 7 - March 20, 2013
Total journey: 15 days and 7 hours
Average flight speed: about 20 miles per hour
Average miles per day: 166
Average altitude over land: 300 - several thousand feet
Average altitude over water: 100 to 300 feet
Longest distance over land: 225 miles
Longest nonstop flight, mostly over water: 530 miles
Longest ground stay: 2 days due to inclement weather in Virginia