WELLING — A visitor to the home of Don and Joyce Varner, seeing the feeders by the side of the house and the owl carved from a tree trunk, is served notice that serious birders live here.

The Varners have been birding since before their marriage, beginning in Illinois and learning about Oklahoma birds after arriving in this region 33 years ago.

They are among an estimated 61 million North Americans who enjoy bird-watching as a hobby or as a serious avocation.

Don, a retired professor of education and reading at Northeastern State University, and Joyce, who worked at the Muskogee Public Library and Jess Dunn Correctional Center, still find plenty of time to devote to their beloved birds.

Don keeps a daily checklist of birds, marking off each species as he sees one of its representatives.

If they stay at home and keep an eye out, they can see about 30 types of birds daily in their tree-rich yard, depending on the season. If they drive around some in the area, they may see 60 or 70 different species.

It was a telescope, not a pair of binoculars, that led Don to his first bird watching experiences.

“I got interested first when I was 16. My hobby was astronomy and in an astronomy magazine, there was an ad for people to help count migratory birds by looking at the moon through a telescope and counting the birds that flew by,” he said.

He did that for two or three years, then met bird watcher T.E. Musselman of Quincy, Ill., an expert on bluebirds. Musselman taught Varner how to build and put up boxes for the bluebirds to live in.

About that time, Don and Joyce also met each other.

“Our Friday night dates were going out to check the bird boxes,” Joyce said.

Together, they counted the number of young birds and banded them to see if they would return to the area. They became increasingly interested in bird-watching.

Over the years, their bird-watching has taken them through most parts of Oklahoma and around the nation. In January, Okie Bird listed them as “Birder of the Month.” Each June, they participate in breeding bird surveys for the U.S. Fish and Wildlife Service.

“They give us a randomly selected 25 miles of road. We drive through and stop every half mile, look and listen for three minutes, and record the birds we hear and see. That’s a census that records the number of birds,” she said. “Every summer for about the past 20 years, we do what is called a MAPS — Monitoring Avian Productivity and Survivorship — study.”

For this effort, they catch birds in nets 20 feet long and 7 feet high. The nets are finely woven, rather like a hair net. They check the birds for their general health and condition, and whether they’re molting, whether they’re male or female if that isn’t readily apparent from their coloring.

“Since we’re banding them, some of them will come back the next year. Of course, not all of them survive,” she said.

Their site is one of about 400 in the United States. The study is performed eight times during the summer.

“We just get the data and send it to the Institute for Bird Populations in Port Reyes, California,” Joyce said.

For the last two years, the study also has involved taking samples of bird droppings for analysis. The institute sends the material to the University of California at Los Angeles for study of diseases such as bird flu and West Nile virus.

“The college kids are always wanting to help with it until we tell them you have to get up at 4 a.m.,” she said.

They erect the nets at dawn and are finished by 11 a.m., so the birds won’t be stressed by the heat.

“We’ve also completed two Oklahoma atlas projects compiled by the Sutton Center. Each of those was five years long,” she said.

The Varners have found birding a rewarding lifetime passion.

What advice to they give prospective birders?

“Find someone who knows,” Joyce said.

“Join a group like the Audubon Society and go to a meeting. Go on field trips. It’s hard just to start by yourself without having someone who will tell you the species.”

One project involved summer birds, the other birds that winter in Oklahoma. Don wrote articles for the books on hairy woodpeckers and whippoorwills.

“We do the Christmas bird counts each winter sponsored by the Audubon Society. It’s one of those things that’s not scientific, except that it’s been done so many times in so many areas by so many people it becomes scientific. It ends up being scientific by sheer numbers,” he said.

Over the years they have observed that some species, such as the fish crow, have greatly increased in numbers. The cardinal, tufted titmouse, Carolina wren and Carolina chickadee also have shown a population increase.

Cardinals have not been affected by the brown-headed cowbird as have some species. The cowbird lays its eggs in other birds’ nest, and its chicks are raised at the expense of the birds’ own babies. Cardinals are able to raise both species together, and their chicks have thrived along with the cowbird chicks.

“For each one of those, there’s been at least 10 species that have decreased, and some disappeared, in our study area,” he said.

Those birds include many of the little warblers, the catbird, and vireos in general.

“Unlike many of the warblers, though, the Kentucky warbler has been on the rise,” he said.

Sometimes people looking for eagles around the Fort Gibson dam get excited when they see large birds circling the dam, then realize they are vultures. Black vultures especially like feeding on the fish around the dam and have increased in the area, the Varners said.

They believe the loss of habitat, through development and destruction of forested land, has contributed to the decrease in many species.

Joyce Varner said studying birds teaches things not readily apparent to the casual observer of backyard birds.

“We have robins here year-round, but the robins I see in the summer are not the robins I see in the winter,” she said. The birds have different migrating patterns, with different individual birds visiting the area in different seasons.