"Perched on a nest atop a green navigation marker in Maryland’s Harris Creek, the osprey glared, spread its wings and started hopping as a boatload of people drew near.

'That’s a pretty big nestling standing up,' observed Barnett Rattner, a veteran scientist with the U.S. Geological Survey’s Eastern Ecological Science Center. 'Last week, there were two.'

Peering at the agitated fish hawk through binoculars, Rattner spied the telltale reddish-orange eyes of a juvenile, so the boat halted its approach. They didn’t want to spook the youngster into trying to fly before it was able. It would almost certainly fall in the water and drown — perhaps the fate of its missing nestmate.

Rattner and USGS wildlife biologist Dan Day have been visiting osprey nests around Tilghman Island on Maryland’s Eastern Shore every 7 to 10 days since early spring. They’re part of a multi-pronged effort to assess the birds’ breeding success around the Chesapeake Bay following a troubling report last year of a drastic reproduction decline in Virginia’s Mobjack Bay. . ."