CAMBRIDGE -- The icy night sky was blushing pink in the east when Bob Davis spotted a large winged shape in the dimness, flapping, then gliding low over the marsh grass.
It was a short-eared owl. "See him?" Davis asked his companionJulie Kelly. "See those machinations, that easy, loping, sugar-footing? See him, Julie? That's a life-bird for you, babe."
The excitement in Davis' voice belied the hour and the temperature. It was before 7 a.m., and the thermometer had yet to break 30 degrees.
But Davis had already been up for four hours, and he was going strong. He had awakened at 3 a.m. to drive in the darkness from his home in Glendale to Blackwater National Wildlife Refuge in Dorchester County.
Davis, a product specialist for Xerox Corp., was spending his day on a grueling 12-hour trek by car and foot around, and around, and around the wildlife refuge 15 miles south of Cambridge. Kelly made a similar, wee-hours journey from her home in Kensington.
They were joining in the Christmas Bird Count, a 91-year-old bird-watching tradition organized by the National Audubon Society.
From before dawn until after dusk, Davis, Kelly and 12 other hardy souls tramped through frigid fields, forests and marshes to record every bird they could see or hear and identify. Each paid $5 for the privilege.
"My family, my in-laws, all think I'm mad," said Kelly, who works for the Audubon Naturalist Society in Chevy Chase.
The count began in 1900 as a protest against the "side hunt," a popular Christmas Day sport at the turn of the century in which teams of hunters vied to shoot anything that moved. The winning side was the one with the most feathered and furry carcasses at the end of the day.
The aim of the count, by contrast, is to tally every bird seen in a single day without harming any of them.
The Dorchester count is just one of 22 day-long counts that take place every year in Maryland. The last holiday count takes place tomorrow -- New Year's Day -- in Annapolis.
Overall, more than 1,600 counts are conducted throughout the United States and Canada, Central and South America -- even in Guam and Saipan. More than 35,000 people participated last year.
Once a Christmas Day tradition, the count is now spread out over the two weeks before and after the holiday, mostly on weekends.
Last year's avian census tallied more than 54 million birds of 587 species in North America alone, said Geoff Baron, the New York City-based editor of the bird count statistics.
Maryland accounted for nearly 900,000 of those birds, he added, with the greatest variety in Ocean City -- 136 species.
The total can vary greatly deal from year to year, LeBaron said, depending on whether chance brings large flocks of blackbirds, grackles and starlings to the count areas.
Davis and Kelly were on the lookout for everything from bald eagles to "dickey birds," a nickname Davis applied to "all the little birds out there."
While participants must count every bird they see as they travel pre-set routes, serious bird-watchers like Davis are on the lookout for the unusual.
"I'm not wild about counting mallards, but I'll do it," Davis said, as he scanned distant flocks of the mundane ducks through his binoculars. "I'm just looking for something else first."
Davis spied a pair of common loons, and Kelly found a black-crowned night heron lurking under some branches behind a flock of mallards.
While bird watching is normally a leisurely pursuit, counts are intense, requiring speed and precision. When he wasn't walking, Davis frequently jerked his Acura Legend to a halt as he spotted a bird on the wing, on a wire or in a tree.
From time to time, Davis and Kelly tried luring birds from cover with calls of their own that sounded something like "sssp, sssp, sssp" and "sshh-psshh-psshh."
They also checked well-thumbed field guides.
"I don't care how good a birder you are, you always have a guide on you," Davis explained.
His guide, which also served as a folder for his bird tally, almost proved his undoing when he left it on the roof of the car after one stop. He discovered its absence a mile later, and it took a frantic 15-minute search in the failing light to recover the book and the all-important scraps of bird count paper, which were scattered along the road.
Well after dusk, Davis drove to the Quality Inn Motel in Cambridge to rendezvous with his colleagues.
There sat Chandler Robbins, a noted bird biologist with the U.S. Fish and Wildlife Service, co-author of the Golden Books field guide for birds, and the count's leader, or "compiler."
Robbins has missed only one Dorchester count in 45 years. He took part in five of Maryland's 22 bird counts this year -- three of them in three consecutive days last week.
Robbins sat in the middle of the group at the motel's restaurant, taking down the reports of sightings between bites of dinner.
When it was over, he announced that the group had counted 43,216 birds of 103 different species. That was a little lower than last year's 45,433 birds of 112 species.