This Weeks Creature Feature … So Long, See You Next Year

Somebody’s bound to be the last osprey to turn out the lights on summer 2012 on Chesapeake Bay.
    By eight weeks old, this year’s babies were as big as their parents and ready to leave the nests. By the end of July and early August, you could see the youngsters trying out their wings, fishing skills and independence.
    Babies raised, parent osprey were free to head south. Mothers were out of here by mid to late August. They weren’t turning off any lights. Males and youngsters stayed longer, most starting their journeys in September. The birds competing to turn out the lights may linger all the way into November.
    But competition is whittling down. The rare osprey you see at September’s end may be a baby who hasn’t yet talked itself into leaving home for the big, unknown voyage that could take him as far as South America. Or perhaps Central America, a Caribbean island or our own south.
    “They just need to fatten up and wait for a nice brisk wind out of the north,” says Rob Bierregaard, soon to become an affiliate of the Academy of Natural Sciences in Philadelphia. He’s studied the birds since 1969, starting in Martha’s Vineyard. Tracking their movement by satellite for 13 years, he’s learned how they nest, fish and migrate.
    The occasional bird you see could also be a northern osprey fishing Maryland as it wends south.
    Osprey migration is no beeline. They circle, stop off in attractive locations, stay as long as the fishing is good and the weather mild, then move on.
    Just as easily, they can fly great distances nonstop.
    Along the migration route, the dangers are great: weather, exhaustion, technology, competition, chance.
    Storms and hurricanes can down birds or strand them over the open ocean. Fish farmers in developing nations can shoot down poaching birds. Power lines can electrocute and entangle birds.
    With luck, a bird’s internal compass will eventually guide it to a warm and lovely spot to overwinter. Youngsters will devote two seasons to learning that territory. So the birds fledged this summer won’t return until 2014.
    But by next February, adults will be winging back to arrive in Chesapeake Country near St. Patrick’s Day.    
    See for yourself at www.bioweb.uncc.edu/bierregaard/migration12.htm.