Access For All

Creating a Wild Backyard: Eastern Bluebirds

The eastern bluebird is perhaps
Maryland's most popular songbird.

The male bluebird can be distinguished from other birds that are blue, like bluejays and indigo buntings, by its orange chest and white belly. The female looks like the male, but her blue coloring is less bright and has a brownish tinge. The official bird of Prince George's County, eastern bluebirds live throughout Maryland.

Natural History
Bluebirds are very common in farm fields and other open, rural areas where woods are found nearby. In the summer, bluebirds eat insects. They are favored residents of farms because they eat many of the insects that damage crops. In the fall and winter, bluebirds move to the southeastern states. Some Maryland bluebirds remain as year-round residents.

To nest, courting male bluebirds find an attractive tree hollow or man-made nest box. When the male has chosen a nest site, he sings near it to try to entice a female to join him in setting up housekeeping. About five bluebird eggs appear in the nest in early spring and hatch about 12 days after being laid. Once the young are on their own, the bluebird parents will often raise one more brood before fall comes.

Miraculous Bluebird Recovery
By the 1950's and 1960's, the numbers of bluebirds dropped dramatically. The reason for this was partly because less and less farm land, favored by bluebirds, was available, and because of competition for the bluebird's nesting places from house sparrows and starlings. These birds can easily take over a bluebird nest. There were other contributing causes, including the use of pesticides like DDT. These affected the bird's food supply directly and their reproductive success indirectly, causing thin egg shells which would not support developing young.

In the early 1970's, the plight of the bluebird was recognized throughout the eastern United States. Wildlife groups and bird clubs began to build and erect bluebird boxes. Both the bluebird nest boxes and the ban on the use of DDT have lead to a miraculous increase in the numbers of bluebirds. The bluebird and the bluebird nest boxes have become symbols of this success story in wildlife conservation.

How You Can Help
Build a bluebird box! It's easy and will be a fun family project. You'll find directions below.

Here are just a few suggestions:

• You will have greater success if you erect your boxes in large, open areas, such as fields or farmland.

• Do not put a perch on the front of the bluebird house. Bluebirds don't need a perch, but starlings will use it to enlarge the entrance hole so that they can move in.

• If you plan to build a line of bluebird boxes, place them at least 100 yards apart.

• Put up your boxes by the third week in February.

• Place the box 4-6 feet above ground and install a predator guard on the pole or support structure.

• Place your bluebird box at least 100 yards away from buildings.

• Remove the nest from the box after the young leave so that another brood can be raised in it.

• Clean and repair the box after the last brood leaves. This will probably be in late September.

• Painting your bluebird box is not recommended.

• House sparrows and starlings may try to move in to your box. It is legal to remove or destroy the nests of these two bird species.

How to Build a Bluebird Box

There are many kinds of bluebird boxes. A simple nest box, like the one described in the instructions below, is beneficial and easy to make.

Materials:

• Carpenter's glue

• 1 " nails

• 1" x 6" x 6' untreated lumber

• Small non-corrosive hardware hook and eye

• 4' to 6' wooden post

• Length of stove pipe or metal collar for predator guard.

Construction

1. Mark and cut the pieces out of the lumber.

2. On the front and guard piece, make an entrance hole 1 1/2" wide. Larger holes attract starlings.

3. Attach the guard piece to the front piece with 2 nails and glue.

4. Drill a small hole one inch from each short side of the back piece. Use these holes to attach your bluebird box to the post.

5. Trim the corners of the floor piece diagonally.

6. Use nails and carpenter's glue to assemble the box, leaving one side open. Leave a 1/4" space between the roof and the sides for ventilation.

7. Attach the second side piece with 2 nails at the top, not through the roof but with the nails penetrating the front and back of the box. These are "pivot" nails that will allow you to open the box from the side to check the nest or to clean the box.

8. Attach one part of the hook and eye to the "pivoting" side piece and the other part to the side of the front piece as shown.

Acknowledgments: Blue Bird Nest Box plans courtesy of Minnesota DNR, Woodworking for Wildlife.

For Additional Information, Contact:
 
 Wild Acres Program
 Maryland Wildlife and Heritage Service
 Attn:  Marilyn Mause
 Gwynnbrook WMA
 3740 Gwynnbrook Ave
 Owings Mills MD 21117
 410-356-0941
 E-Mail: customerservice@dnr.state.md.us