Chesapeake Bay Ospreys Flying High After Drop in Numbers

Walking barefoot along a narrow steel beam 65 feet above the ground at the U.S. Navy’s radio transmitting facility here, antenna mechanic John Schorpp swayed perilously in a sudden breeze, twisting with outstretched arms to keep his balance, a camera swinging crazily from his neck.

Ahead, straddling girders inside the huge antenna, lay a conspicuous mound of twigs and branches, a nest fashioned by ospreys high above the Chesapeake Bay. The mother hawk circled the tower, shrieking alarm, as Schorpp inched forward and peered into the nest.

“Oh my God!” Schorpp yelled. “This egg in here is hatching. The chick’s coming out right now!”

Schorpp found two hatchlings in addition to the one emerging in the nest. It was another milestone for the transmitting facility’s growing population of the fish-hunting ospreys.

Before his arrival here six years ago, Schorpp would have found little to crow about in the forest of radio towers that loom over the capital. Ospreys and the Navy weren’t exactly on speaking terms then.

Navy Destroyed Nests

Unimpressed by the ospreys’ choice of nesting sites, Navy officials did their best to keep birds away. Often, nests were destroyed before eggs could be laid.

Schorpp, a nature lover who walks the razor’s edge, changed that. With 12 nests thriving in the transmitting facility, he has emerged as one of the Chesapeake’s preeminent osprey landlords, helping the birds on a remarkable comeback from a time two decades ago, when DDT and other pesticides threatened the birds with extinction.

Ospreys now seem to be multiplying like rabbits around the bay, partly because a growing number of amateur ornithologists have taken up the birds’ cause.

These large hawks have become an object of intense fascination for boaters, who marvel at the birds’ ability to snare fish by diving into the water feet-first.

Osprey couples have set up housekeeping on hundreds of navigational buoys and channel markers and seem to have an unusual tolerance for boat traffic in the bay’s marinas.

Nesting platforms are springing up behind docks and weekend houses along miles of the shoreline.

“Ospreys essentially have saturated the area,” said Glenn Therres of the Maryland Forest, Park and Wildlife Service. “The population is at an all-time high.”

The comeback is all the more remarkable in light of the pollution, overfishing and traffic congestion in the bay. Some researchers say the hawks are merely riding a run of good luck against losing odds, after having been pushed out of their old nesting grounds by waterfront development.

“I think it’s miraculous that some of these animals have been able to hang on as well as they have,” said biologist Jan Reese, who spent 20 years studying ospreys out of St. Michael’s, Md., on the bay’s Eastern Shore. “The osprey is obviously one adaptable bird. Somehow, it’s managed to hang on this long.”

Therres said the osprey population around the bay has come back from a low of perhaps 800 pairs in the late 1960s to about 1,500 today. Measuring the change is tricky, Reese said, because no accurate count of the birds was made before it was discovered that DDT was causing serious reproductive problems.

Reese plunged into the osprey investigation after researchers in Britain in the 1950s uncovered evidence that DDT was causing peregrine falcons to lay abnormal eggs.

Using the scant osprey records here for comparisons, Reese concluded that pesticides were having the same effect on ospreys. By the early 1970s, he said, osprey reproduction had fallen from an average of two or more eggs to a nest to one egg--or none.

A ban on DDT and restrictions on use of other pesticides have brought substantial improvement. Ospreys now commonly lay two, three or even four normal eggs. Other events have brought some good news, and some bad news.

Building along the bay shore has meant the clearing of many acres of woodlands that may have provided nesting sites for 30% of the ospreys, Reese said.

At the same time, though, a surge in recreational boating has prompted the Coast Guard to plant hundreds of additional channel markers and other navigational devices that house-hunting ospreys find ideal.

Popular boating myth has it that the Coast Guard designed the buoys to accommodate ospreys, but in fact, the Coast Guard for years tried to discourage the birds because they sometimes short-circuit navigational lights and their bulky nests interfered with buoy maintenance.

‘A Monstrous Nest’

“They’ve found many ways to make the lights go out. And they can build a monstrous nest in one year,” said Lt. George Walker of the Coast Guard’s navigational-aids unit in Portsmouth, Va.

Shooting the hawks or destroying their nests ran the Coast Guard afoul of environmentalists, and a cease-fire was necessary after the osprey was designated a protected species.

Now the guard removes nests for maintenance only at the end of the breeding season. It sometimes builds alternative nesting platforms around sensitive navigational lights.

“We all learn,” Walker said. “Environmental protection is much more of a concern now than it was then.”

Those changing attitudes encourage biologist Paul Spitzer, who, under a state contract, has been tracking many of the ospreys Reese banded on the Eastern Shore.

The birds winter in South America and typically return to the same nests here to raise new broods.

Spitzer said construction of nesting platforms by local property owners has given the osprey a significant boost.

States Share Chicks

Breeding is so successful that Maryland has become an osprey exporter. Spare chicks are sent to areas of Pennsylvania and West Virginia to bolster populations there.

“The bay could become a real garden for osprey,” Spitzer said.

The Navy transmitting facility, meanwhile, has been named a wildlife refuge under a cooperative agreement between the state and the Defense Department, and antenna mechanic Schorpp recently received a governor’s award for his work.

Back at the nest in the radio tower, Schorpp had less luck with his camera. It jammed just as the new chick was pulling itself from its shell.

“Wouldn’t you know it,” said Schorpp, slapping the camera as he balanced on his slender perch, 65 feet up. “Just when you need it to work, it doesn’t.”