BETHEL -- On a rare bright warm June day in Southwestern Alaska, a group set out on the Kuskokwim River in two covered boats to look for birds. There was a cook who hadn't had a day off since December but who loved bird-watching in his native Mexico. The volunteer guide who has been birding since college. Assorted Bethel residents. Two couples who own the charter and eco-tourism business Kuskokwim Wilderness Adventures.
Then there was the visitor from Massachusetts, whose sister in Bethel signed her up. She wasn't sure she even liked bird-watching.
Even before leaving Bethel's small harbor, the birders heard a loon. One box on the day's list checked. At an early stop, the group walked through a thicket of cottonwood, willow and alder to a nesting northern goshawk, a reclusive, fierce and protective raptor. Attila the Hun reportedly put an image of one on his helmet.
"They can fly through these trees at top speed, right at you," warned John McDonald, expedition leader, birder and wilderness business co-owner. "If we say 'get down,' get down." This bird stayed on its high nest, its babies hidden, its dark red eyes flashing.
Almost 250 species of birds have been spotted on the Yukon Delta National Wildlife Refuge. Many breed there. About 20, including the goshawk, live in the region year-round. On this trip, birders spotted 51 species, along with moose including two calves.
Fred Broerman, who used to work as a bird biologist and has volunteered with the bird tours for years, identified the call of a yellow warbler, a tiny migrating songbird. The day was brightening and a bird concert was starting up, with common redpolls in abundance and blackpoll warblers too, a fox sparrow and a northern water thrush. "Chee, chee, chee!" they sang, each in its own way. One bird buzzed a bit like an insect.
"That's a Savannah sparrow," Broerman said. More birds are identified by their calls than by sightings, he said.
At a sandy beach, insect-eating bank swallows found plenty of food. At a lake in the nearby marsh there was a red-necked phalarope, a kind of shorebird that is noteworthy because females are more colorful than males.
The river was glassy, disturbed only by the wakes of the boats. They turned from the Kuskokwim onto the Gweek River. McDonald, Broerman and others had scouted out nesting sites before the trees leafed out. At one stop on the Gweek, there was a nesting pair of ospreys -- a big raptor with claws well-adapted for gripping slimy fish.
Soon came the big find: a great horned owl nest high in a birch tree. It's been four or five years since the birders had spotted one. Great horned owls don't make their own nests, but take over abandoned ones from other birds, McDonald said. This one was a messy twig jumble.
Two fluffed-out chicks set their round eyes on the people below. The parents must have flown off. The female owl would blend into the birch bark, McDonald said, showing an image on a bird identification mobile app.
As one of the boats pushed off from the bank, Ruben Cerbents, a bird-watcher back in Mexico, spotted one of the adult owls flying, maybe back to the nest.
"That made my day," said Bev Hoffman, one of the tour business's co-owners.
A treat, said Joanne Brault, a woodworker from Gardner, Massachusetts, home of the world's largest chair. She'd worried that she would be out of place among "a bunch of people hiding out in trees trying to find a certain bird" but it wasn't like that.
New birds kept materializing, almost like the animals that pop up in a theme-park river ride. A young eagle. A long-billed shorebird called a Hudsonian godwit that is believed to fly thousands of miles nonstop to winter in South America. Cloud-white tundra swans.
On the way home, after traveling some 35 river miles, after hours of bird-watching, the lanky Broerman folded himself into the seat next to Hoffman. Then he nearly jumped out of it.
"A solitary sandpiper!" he said. The reclusive shorebird lays eggs in abandoned nests of songbirds.
Another sighting, another box checked, another day of bird-watching near Bethel.