FAIRHOPE, Ala. — While many people slept in warm beds last week, a group of scientists and research volunteers braved near-freezing temperatures during several predawn trips aboard the Estuarine Queen on the Magnolia River to search for birds — birds few people have seen or heard.

“This is the first year we’ve had a formal training session,” said Eric Brunden, stewardship coordinator at Weeks Bay National Estuarine Research Reserve, who helped organize last week’s workshop to train the dozen participants in how to survey these secretive marsh birds by sound alone. “The purpose was to establish a long-term database and determine trends in marsh birds. Our goal was to train agency personnel and volunteers in the Southeast so they can take it home and do it themselves.”

The trainer for the three-day workshop was Nick Bartok, a biologist with the Ontario Ministry of Natural Resources. He in turn was trained by Courtney Conway, a scientist at the University of Arizona, who developed the detailed monitoring protocols for surveying marsh birds and maintains a Web site to gather data collected from sites around the country.

It was still dark when the reserve’s research vessel arrived at the first monitoring site.

“OK, that’s the first bird of the morning, right here,” Bartok said. “Everyone hear that clapper rail kekking?”

He tilts his head and smiles.

The others face in the direction of a sound, which changes to a clattering — a sound like chopsticks banging together — with gloved-hands in pockets, parkas zipped up, peering out from ski masks and hooded jackets.

They all listen together, as the light starts showing in the dark sky to the east.

“If you were starting your own survey, this would be late.” he said. “Soon as you can see the light on the page, that’s the time to start.”

He gives some final instructions on how to notate the spreadsheets of the birds they will be listening for. Some in the group take their gloves off and blow on their hands, while others hold pens in heavy mitts.

“OK, I’ve got 6:07,” Bartok told the group standing with clipboards in hand. “So write down 6:07 as start time.”

Then Bartok leans down, aims the CD player at the front of the boat into the marsh a few feet away, and presses “play.”

The sounds of the birds they are hoping will respond echo across the marsh.

Bloonk-adoonk. Kickee-doo. Kek-kek-kek. Pep-pep-pehr-peehr. Cheup-cheup-cheup. Gack-gack. Gwaaaaow. KooEE. Click-click-click.

Those are some of the mating calls, respectively, of the American bittern, black rail, clapper rail, common moorhen, king rail, least bittern, pied-billed grebe, sora and yellow rail, as described phonetically in the Standardized North American Marsh Bird Monitoring Protocols written by Conway for the U.S. Geological Survey.

After the calls are played, the dozen researchers stand and listen.

Sounds start up in the marsh and the group starts scratching on their notepads.

“How many did ya’ll have?” Bartok asks. “We had this one guy keking, and another over there did a clatter. I had six. It’s a good spot.”

“For clapper rails,” Brunden says. “Let’s try another.”

They motor to a different part of the river and land in the marsh where the houses along the shore are a mix of mansions, trailers and cabins.

Then an animal almost as rarely seen as marsh birds shows up.

“There’s an otter,” Brunden shouted. “He was in the marsh.”

The large mammal popped up a few yards from the port side of the boat, then dove and resurfaced at the rear.

Half the group ran to the back, cameras being pulled out of cases.

The otter surfaced several times, always looking back at the boat.

“He’s having fun,” said Harvey Joanning, of Fairhope.

Now most of the rest of the group has come to the side to watch the river otter.

“I guess the mammal trumps the birds,” Brunden said.

Conway, one of the leading experts on marsh birds, is familiar with what happened on the river that early morning: playful cute animals like otters getting all the attention.

“These birds are overlooked, not just by people but by scientists,” he said. “What drew me to them was there was basically nothing known about them. You virtually never see them. You often have to slog through muck to find them.”

Conway began developing methods for surveying these rarely seen birds more than a decade ago. The results were the procedures that the group last week learned how to use.

“I guess I was drawn to them for the same reason that people are drawn to underdogs,” he said.

He also pointed to some rare habits of the birds that were heard out on the water last week.

“There aren’t many examples of paired duets in this country,” he said, referring to a paired clattering that two birds make together once they become mates. “It’s intriquing how they do it so quickly and are able to identify each other that way.”

On the last day of the trip, the group did get a rare sighting of one clapper rail.

“After the calls were broadcast, one of the birds actually came out,” said Angela Underwood, an education specialist at the reserve. “He just came right out. I don’t think many people even know these birds exist. They’re an indicator of marsh quality and the health of the ecosystem.”