When Bob Antonio began bird-watching about 25 years ago, he didn’t have to go far to find a northern bobwhite.

Antonio could spot the ground-dwelling, robin-sized bird at Lawrence’s Burcham Park. Not anymore.

“I used to get them in Burcham Park nearly every year,” the Lawrence man said. “Now I haven’t gotten one in a decade. I’ve just been amazed.”

Declining populations

In the last 40 years, North America’s northern bobwhite population has sunk by 82 percent. It’s not alone: Several common Kansas birds have seen huge chunks of their populations disappear during that time.

At least eight of the 20 bird species named last month in an Audubon Society report reside regularly in Kansas. Several more pass through the state seasonally.

Each of the species in the Audubon Society report has seen its population drop by at least 50 percent in the past 40 years. Other Kansas birds on the list include the eastern meadowlark, whose population fell by 72 percent in 40 years; the loggerhead shrike, down 71 percent; and the common grackle, 61 percent.

An analysis of Kansas bird surveys shows that all three of those birds, as well as the northern bobwhite, have experienced similar declines within Kansas, said Bill Busby, a Kansas Biological Survey scientist.

“The big picture is, we’re experiencing the same thing here in Kansas that they are across the country,” Busby said.

Prairie life

While the national Audubon Society list contained a diverse group of species that included ducks and aquatic birds, most of Kansas’ declining birds share a link: They live in prairies and grasslands, where many of them nest on the ground.

Mark Robbins, an ornithologist at the Kansas University Natural History Museum, said this link pointed to the biggest reason for declining bird populations in Kansas: destruction of the state’s prairies.

“The major problem for many birds is the conversion of grasslands to cultivation,” Robbins said.

Many birds that are declining in population live in tallgrass prairies, which Robbins said was North America’s most-endangered ecosystem. About 98 percent of the original North American tallgrass prairie is gone, he said, and what’s left consists of small fragments.

The largest patch of tallgrass prairie left is the Flint Hills area in Kansas. Tallgrass prairie once consumed the entire eastern third of the state.

Greater prairie chicken

Robbins said the tallgrass prairie’s deterioration was evident in the population of its “flagship species” – the greater prairie chicken.

It was not on the Audubon Society list, but the greater prairie chicken population also has dropped. Robbins said it had disappeared from several Midwestern states where it was once prevalent. In Kansas, greater prairie chicken populations have declined by about 56 percent since 1980, according to surveys by the Kansas Department of Wildlife and Parks.

Robbins said Douglas County’s last prairie chickens left about three or four years ago. He said the county’s prairie, which once took up about 80 percent of the area, has all but disappeared.

“Douglas County has gone through a huge conversion,” Robbins said.

Most of the state’s tallgrass prairie has been plowed for cultivation or turned into pastures where farmers use intense, regular field-burning that damages the grassland habitat.

Robbins said the decline in grassland birds might not matter to someone who’s not a bird-watcher or an ornithologist, but the decline suggests a grassland deterioration that could be more troubling.

The plants in grasslands and prairies have deep roots, allowing them to absorb huge amounts of carbon, Robbins said. This means they could help reduce global warming by taking carbon out of the atmosphere. But when a prairie is plowed for farmland, its carbon absorption decreases significantly.

So a decline in grassland birds could indicate an increase in carbon.

“Birds are a good bellwether of what’s going on in the grassland,” Robbins said.

He said one measure to help birds that rely on grassland habitats would be to protect the federal Conservation Reserve Program, which prohibits cultivation on some land.

Stan Roth, a Lawrence bird-watcher with more than 50 years of experience, said bird populations always tended to ebb and flow.

“Many of these natural cycles are based on a wide variety of natural phenomenon that we don’t necessarily understand all that well,” he said.

Roth, a former high school biology teacher, said the eastern bluebird had a resurgence after a population drop about 20 years ago.

Robbins said humans’ presence had actually helped many bird species – such as blackbirds, robins and geese – that have adapted to cities or farmland.

Even the northern bobwhite may be bouncing back, as Roth and Antonio both mentioned seeing an increase in bobwhites in other parts of the state during the last two or three years.