Efforts Pay Off To Attract Bluebirds to Nesting Boxes on Island Nature Notes By

Patricia Martin

Recently, I had an interesting conversation with Frank Bloswick Jr. about the Bluebirds nesting in his yard. Yes, I said Eastern Bluebirds. Frank has been trying to attract them to his yard in Harrisonville and has succeeded. He put out bird food especially designed to attract Bluebirds, but the birds didn’t seem to particularly appreciate it. He placed two Bluebird boxes in his yard, one in the open and one near more cover, and the parent birds chose the one in the open. They’ve successfully raised their young and can now be seen in the trees across from the house. I was rather pleased to hear about his success, as it’s the first time anyone has mentioned Bluebirds nesting on the Island in recent memory.

Bluebird

The male Eastern Bluebird has bright blue upper parts with a reddish/brown chin, throat, neck, breast, sides, and flank. The belly and under tail are white. So really we ought to call them Eastern Blue, Red, and White Birds. The female is less colorful, with gray upper parts, blue wings, rump, and tail, a pale chestnut throat, breast, sides, and flank, and a white belly. These birds have a melodic song of chur, chur-lee, chur-lee and the male gives a call of true-a-ly, true-a-ly.

This bird naturally inhabits open woodlands, meadows, and fields. They typically live in the eastern United States, Mexico, and

into the southern part of eastern Canada. They winter in the southern U.S. and Mexico. Winter flocks can be made up of more than 100 birds.

During the spring, when they have moved somewhat north, mating begins. The courting male sings and flutters in front of the female, with their wings half open, tail spread, and then perches beside and preens the female and may even offer her food (sounds like some dates I’ve been on). After pairing off, they’re monogamous, and the female builds their nest. They normally build a cup-shaped nest of grass, weed stems, pine needles, and twigs in a hollow cavity in a tree between two and 50 feet off the ground. Often these cavities are old woodpecker holes. It may take the female 10 to 11 days to build the nest. It is the nesting sites that have produced a challenge to these birds in the last century.

Eastern Bluebirds used to be abundant; however, in the last 100 years their numbers have fallen 90 percent. This is owing to several factors, including loss of proper housing. Many of the old snag trees, which had wonderful holes, have been felled or old branches removed, which has reduced their nesting sites. In addition, there has been increased competition for these sites by European Starlings and House Sparrows, whose numbers have been on the increase since their introduction. In the last years the population has somewhat stabilized, in part because people have been putting up Bluebird boxes with the appropriate hole size.

The female Bluebird produces four to five pale blue to white, unmarked eggs that are less than an inch long. She will usually produce two broods each year. The eggs take up to a couple of weeks to hatch. Three weeks later the young are fledged. During these weeks the male and female help feed the young, sometimes with help from members of the previous brood. Their food includes earthworms, snails, and other invertebrates. They often hawk the insects from low perches, catching the insects near the ground. Bluebirds will also glean insects from the foliage of trees and shrubs. In the winter they’re heavily dependent on fruits for survival, especially berries.

Because we’ve already had one successful Bluebird nesting on Mackinac, it may be very possible to expand the trend. A birder friend of mine suggested that Frank Bloswick may want to move his second Bluebird box near the one that the birds used this year. Bluebirds will often return to a box or an area if they’ve been successful in producing a brood. It’s good to have a second box in case House Sparrows move into the first. It would probably be a good idea to build other bird boxes in the area. One thought has been to put some around the opening area at Turtle Park to attract more of our bright blue friends. According to the Audubon Bird guide, the hole in a Bluebird house should be less than 1.5 inches in diameter to exclude starlings, and the boxes should be placed no higher than a fence post to discourage the House Sparrows.

Perhaps if we make and hang a few of these boxes, we might have “Bluebirds over the high cliffs of Mackinac” to quote (with a slight alteration) the beautiful song from World War II.

P.S. There have been a number of sightings of the Golden Eagle that I wrote about last week. One occurred near the airport. Several others have been near Stonecliffe and the Woodbluff development. All of the sightings have seemed reliable and the spotters have all had binoculars.

Trish Martin is a year-around resident of Mackinac Island, has earned a master’s degree in botany from Central Michigan University, and owns Bogan Lane Inn.