It’s time for bluebird weather

For several years, I was a volunteer at Canoe Creek State Park to monitor a group of bluebird nesting boxes in part of the park.

That fascinating project provided me with day-by-day access to dozens of bluebirds and tree swallows as they built nests, laid eggs and tended the young birds until they fledged and left the box for good. I thoroughly enjoyed watching and photographing all aspects of that wondrous natural process firsthand.

Eastern bluebirds are cavity nesters that prefer fields and open areas surrounded by some trees or shrubs. These beautiful native songbirds suffered severe population declines during the twentieth century due in large part to changing land use and to competition for nest sites from the introduction of invasive non-native species like starlings and house sparrows (formerly known as English sparrows). Providing manmade nest boxes has helped the resurgence of bluebirds throughout Pennsylvania.

Property owners who would like to attract bluebirds should consider erecting a few bluebird boxes around their backyard or other suitable locations around their property. The Pennsylvania Game Commission offers wooden bluebird nest boxes, either completely assembled or as do-it-yourself kits with assembly instructions. A single box sells for $11.66 or $10.60 each when purchasing two or more boxes. Those prices include sales tax.

Boxes can be purchased at the Game Commission regional office in Huntingdon, any of the other five regional offices or from the Game Commission’s Howard Nursery located at 197 Nursery Road in Howard. Nesting boxes can be ordered and shipped directly from the Howard Nursery by calling 355-4434 or online at the Game Commission website, pgc.pa,gov, by navigating to the Howard Nursery page. Place your cursor on the “Information & Resources” tab at the top of the homepage, then click “Get Involved,” and select “Howard Nursery” to find the “2019 Wood Products Order Form.” Be advised, however, that shipping costs will exceed the price of the nest boxes themselves.

For those proficient at woodworking, complete plans for building bluebird boxes can be obtained on the Game Commission website. On the homepage, click on “Wildlife” in the menu bar at the top of the page, then the “Birding” tab, and scroll down to “Eastern Bluebird” under the “Natural History” heading. On the “Eastern Bluebird” page is a link to “Bluebird Nesting Box Plan.”

Bluebirds are early nesters, so now is the time to place new nest boxes. For best results, bluebird boxes should be mounted on a post or pole 3 to 5 feet high. If possible, the opening in the box should face south and toward a nearby tree. The nest boxes are designed so that one side can be opened for cleaning at the end of the nesting season or for a quick peek to see what is happening inside.

Once a pair of bluebirds claims a box as their home, they will spend several days building a nest from grasses, weeds, pine straw or other fine-textured material that might be available nearby. The female then lays four to six light-blue eggs, which it will incubate for 12 to 14 days. Both parents tend and feed the young birds until they are fledged and ready to leave the box about 18 days later. Because they begin nesting from late March to early April, many bluebird pairs will then produce a second brood by early June.

Bluebird next boxes will also attract other native species, such as tree swallows and house wrens, which are desirable and interesting to watch. Non-native starlings and house sparrows, however, can be a problem. The inch-and-a-half diameter opening used in bluebird boxes is too small for starlings and will keep those pests away. The smaller house sparrows will readily take over nest boxes if allowed to do so. If you notice house sparrows taking up residence in your box, it is advisable to remove their nest to discourage them. Although that sounds harsh, these imported birds thrive without any help from humans and will outcompete many native bird species if allowed to gain a foothold.

Looking back at my notes from the seasons of monitoring nest boxes, I began to observe courtship and territorial behavior around several of the boxes from both bluebirds and tree swallows by the end of March and early April. The first strands of nest material typically appeared in some nest boxes by the first week of April. By the last week of April, some contained completed nests, and nests in the early stages of construction were underway in several others. The first bluebird eggs usually appeared by the first week of May, and by the middle of that month most of the other nests were complete with the first eggs as well.

With the first day of spring now less than two weeks away, erecting a few bluebird boxes around your property can be a great way to enjoy some “bluebird weather” all spring and summer long.