A fish hawk wheels out of the gray sky as a rainy wind blows against the shore the Chesapeake Bay south of Annapolis. The white headed bird with hooked claws –- an osprey -- circles above the leafless trees and bent reeds before landing on a nest of sticks.
Soon a second osprey appears with a fish in its claws. It circles, then lands beside its mate on the platform atop a telephone pole. The two are among the first osprey to return to the Chesapeake Bay this spring after an epic migration of more than two thousand miles from South America.
“Spring, after a dreadful winter for some, is finally here," said Don Baugh, Vice President for Education at the Chesapeake Bay Foundation. "The osprey are more of a harbinger of spring than Saint Patrick’s Day, more of a harbinger perhaps than the Equinox.”
Suddenly, a great blue heron swoops low over the nest. An osprey leaps into the air and attacks the much larger bird. The osprey dive-bombs the back of the heron, with the osprey's claws outstretched as weapons to fight off the intruder.
“Whoa!" said Baugh, as he watched the aerial confrontation. "The osprey is basically taking its territory and saying, 'No!' Wow! What a wonderful site that was.”
Osprey are powerful, majestic, and globe-trotting birds. To better understand the species, the Chesapeake Bay Foundation recently organized a global osprey tracking project.
“This is a really great project --a partnership between Microwave Telemetry and the Chesapeake Bay Foundation to look at the travel habits of birds,” said John Rodenhausen, CBF's Director of Development for Maryland. “We are able to follow the osprey migrations on a website that shows us how they travel not only during the day, but also in their seasonal migration.”
The three birds being monitored are named Nick, Woody and Tango.
Students or anyone curious about the trio's adventures can follow the daily progress of their migration by visiting this website.
The online map shows a dense cluster of purple dots around Tangier Island. This bunch of grapes is where Nick spent his time living and fishing last summer. Then, last October, the dots started moving south -– across Virginia, North Carolina and Florida. Then they set off across the Caribbean, passing over Cuba and Haiti, before ending in a big cluster of purple dots in South America.
That was where Nick spent the winter, beside a river in Colombia called Rio Magdalena. Last week, Nick suddenly was on the move again. His tracking device emitted signals showing he was moving northward toward the Caribbean and eventually the Chesapeake Bay.
The osprey named Tango was still hanging out in Venezuela yesterday, perhaps wisely -– with all the snow and miserable weather up north. Tango has spent the winter beside Lake Valencia, which –- as it turns out-- has fertilizer pollution problems and algae blooms very much like the Chesapeake Bay’s.
“The osprey is cosmopolitan. Our problems are cosmopolitan," Baugh said. "If you look at our nutrient pollution here in the Chesapeake, this is a worldwide problem. If you look at the disappearance of our underwater grasses, it is a worldwide problem. I can assure you, osprey know more about pollution in our waterways than we do, because that’s where they are.”
One thing that is clearly getting better for osprey around the world is their reproduction.
“The Chesapeake Bay population has been growing exponentially since the early 1970s and is absolutely huge now," said Dr. Bryan Watts, Director of the Center for Conservation Biology at the College of William and Mary. "The population bottomed out in the early 1970s at below 1,500 pairs. And we are probably in the neighborhood of 6,000 to 8,000 pairs in the Bay now. Just an absolutely huge population.”
The main reason for the dramatic growth in the osprey population, Watts said, was EPA’s decision in 1972 to ban the insecticide DDT, which weakened the shells of eggs.
Osprey, however, still face threats during their long migrations -– including oil spills in Venezuela, and occasionally being shot by hunters in Haiti, Cuba, and elsewhere in the Caribbean.
So over the next few weeks, as osprey fly home to the Chesapeake Bay, watch the CBF osprey map. Keep an eye out for our friends, Woody, Tango, and Nick. And pray that they make it home, safe and sound.
By Tom Pelton
Chesapeake Bay Foundation
(Photo by Dennis Raulin)