Bluebird population rising, after 35-year BRAW efforts

Early efforts by DNR staff and the continued work by the citizen scientists of the Bluebird Restoration Association of Wisconsin (BRAW), have helped restore and monitor populations of eastern bluebirds. Thanks to this collaborative work, eastern bluebirds’ flash of color and “cheer cheerful charmer” song, are common signs of spring in Wisconsin.

Bluebird populations plummeted 90 percent by the 1980s, and only 600 nesting pairs were observed in Wisconsin. The DNR and a group of Wisconsinites officially established BRAW in 1986, with volunteers taking over operational control of BRAW that same year.

The group now celebrates its 35th anniversary this year, with 750 members monitoring almost 7,000 nest boxes. BRAW members record about 20,000 bluebirds and another 14,000 cavity nesters, annually, such as tree swallows, black-capped chickadees and house wrens, all fledging from their monitored nest boxes.

Members of BRAW are citizen scientists, who build, site and maintain nest boxes, and also monitor and collect useful data about nesting success rates. By doing that, they can provide an early indicator if something trends in the wrong direction, like issues with nesting success or population size.

Over the last 35 years, BRAW members’ observations, combined with research sponsored by the Cornell Lab for Ornithology and the North American Bluebird Society, have improved the design and management of nest boxes.

“Wisconsin members have quickly adopted these advances and added some of their own,” said BRAW president Steve Sample. “For example, we now have a better understanding of where to locate nest boxes to meet bluebirds’ needs for insect-producing forage areas, as well as safety for fledglings.”

Another important aspect of locating nest boxes, is avoiding non-native species and reducing their impact on nesting success. Nest box entrance holes are now only 1.5 inches in diameter, which eliminates competition from European starlings.

Bluebirds nest throughout Wisconsin, but are most common in the southern two-thirds of the state. The bright bluebirds are favorites, in part, because they are tolerant of people and do not need wilderness.

“There aren’t many birds that like a monoculture of short grass – but bluebirds do,” said Ryan Brady, DNR conservation biologist. “They can buzz down and pluck an insect out of the grass.”

This makes bluebirds familiar sights at golf courses, public parks and even suburban neighborhoods, in addition to many other open habitats.

Although a few hardy Eastern bluebirds stay in Wisconsin year-round, most head to southern states for the winter. Early returners show up in March, and start scouting for suitable nesting cavities. Depending on the weather, by mid-April, egg-laying is in full swing.

From egg-laying through fledging of youngsters, the nesting cycle usually runs about five to six weeks. During this period, BRAW’s citizen scientists monitor the nest boxes on a seven to 10-day interval. They record the use of nest boxes, the number of eggs laid and hatched, and how many chicks of all species of cavity nesters successfully fledged. Bluebirds regularly raise two, and occasionally three, broods of young each year.

BRAW is seeking more volunteers to help monitor existing boxes or start a new bluebird trail. To volunteer, learn more about bluebirds, or how to help them in the backyard and beyond, visit braw.org.