The Eastern Bluebird

Rusty Ryan
Conservation Chairperson of the South Mountain Chapter
 of the National Audubon Society

(May, 2010) General information

The Eastern Bluebird (Bluebird) is a native species and the only species of Bluebird that breeds east of the Mississippi River. The Bluebird is a member of the Thrush family that includes the American Robin (a.k.a. lawn thrush). The Bluebird is pretty much a year round resident in this region. That can provide some benefits when it comes to locating and defending nesting sites.

The bluebird is about 6 inches in size, smaller than a Robin, and is often seen perching on overhead wires. The male has a beautiful blue head and back with partial orange-red breast. The female is an overall duller version of the male. Young birds are speckled like young Robins.

The Bluebird is now starting their first nesting attempt. Bluebirds in this area generally nest twice per season with three broods being possible. Landlords should remove used nest material from all boxes as soon as the birds have fledged. This will increase the chances for more use of the box for that nesting season.

The Bluebird is another species that people have helped rebound after declining numbers due to several of man's doings. For example, the introduction of two non-native species (see below) provided competition for nesting sites. The preferred nesting uses of wooden fences were removed from the landscape and the increasing use of pesticides caused problems with this insect eating bird.

Thankfully, issues with pesticides have declined plus someone was smart enough to figure out that the Bluebird would accept artificial nesting if placed in the proper habitat, thus the bluebird box. As far as competition by other species, this is an ongoing issue.

Nesting - Location, location - Just like the Martin, location is very crucial to attracting Bluebirds. Bluebirds prefer open areas comprised of low growing vegetation with nearby perching spots (trees/shrubs, fence line or overhead wires). The entrance to box should be 4-5' above the ground, pointing towards a suitable perch and located opposite of prevailing winds (face easterly). I prefer to mount my nest box on either a U-post or T-post. Both of these green metal posts can be found at most lawn and garden stores. ** When competition exists for nesting boxes, try grouping two boxes in close proximity to each. This technique usually allows different species to nest near each other (a territorial thing).

Bluebirds do not create their own cavities/nest sites so they rely on manmade boxes or cavities created by primary excavators such as woodpeckers. The traditional nest box is made of non-treated and non-painted wood. The wood of choice should be something weather resistant such as cedar or redwood. The round entrance hole of 1.5 inches is critical. The specific dimensions can be found at the web links noted below. Of course drainage and ventilation are important components of any birdhouse. A device located on posts to prevent climbing predators is a good investment. Use your imagination.

Food - The Bluebird is basically omnivorous (eats plants and animals). Insects comprise most of the Bluebirds diet while berries are utilized when the insects are less available. Bluebirds are primarily ground feeders and hence one of the reasons for their preference of open, short grassy areas with some perches. Bluebirds will visit feeders and readily eat mealworms, or a peanut butter/corn meal mixture.

Water - Water is an important part of any bluebird habitat. Bluebird's need a continuous supply of fresh clean water at all times of the year, for both drinking and bathing. Adding a birdbath to your backyard will give you more bluebird appeal! On hot summer days, bluebirds can be drawn to a birdbath kept fresh with a water dripper. During the colder, months, fresh unfrozen water is just as important. A source of water can dramatically increase the number of bluebirds and other species you attract in your backyard. There are many ways to offer water including birdbaths, drippers, misters, shallow dishes and small ponds.

Shelter - In the winter months, Bluebirds tend to flock together. I've seen flocks of 50 during the winter months. During the annual Christmas Bird count conducted by the South Mountain Chapter of Audubon (Gettysburg), volunteers generally tally about 50 Bluebirds within our count area. Most people can't believe that Bluebirds can be found here in the winter months. While they are less likely to be found in the open, I usually find them in the thickest of cover such as those of cedar groves. Roosting boxes (same box as nest box but the front panel is flipped so the hole is located at bottom of box - hot air rises). Bluebirds will utilize artificial roosting boxes. The boxes I now use and those that we sell at our seasonal business, Sugarloaf Valley Gardens, Fairfield offers this option with a simple adjustment of the front panel. A local bluebird enthusiast by the name of Art Kennel has confirmed up to 18 Bluebirds exiting a roost box. I suppose they don't have claustrophobic issues!

House Wren/Jenny Wren (a seasonal native and protected species) House wrens always line the box cavity with sticks. They also create havoc by creating dummy nests that may not even be utilized by nesting wren. They will even go as far as peck holes in Bluebird eggs and even try to discard the Bluebird eggs from box. Avoid placement of boxes near brushy/woody areas. This bird is arriving now and will spend the summer.

European Starling (A year round non-protected and non-native species) If you have the correct size entrance hole on your box than you should have minimal issues with this species. This bird is more competitive for nesting sites with our native woodpeckers such as the Redheaded Woodpecker. Flocks of Starlings will decimate a food supply of berries in the winter months thus competing for food supply.

House Sparrow (A year round non-protected and non-native species) the nest is usually trashy with material comprised of most anything, this bird is more a problem in urban and farming communities, be vigilant and remove nests

Native Species which utilize and benefit from artificial nest boxes

Flying Squirrel, Chickadee species, Tree Swallow, Tufted Titmouse, Wasps, Black Rat Snake, Deer Mouse etc.

What can you do to help this beautiful native bird?

• Provide appropriate nest boxes in suitable habitat.
• Monitor the boxes.
• Be cautious in the application of pesticides.
• Be vigilant when it comes to dealing with of competing species.
• Join a conservation group such as Audubon.
• Educate our young people.

If we as humans can do these simple things, there is no doubt that this beautiful native species can continue to fill our skies, eat some harmful insects along the way and provide beautiful song.

Useful web sites:

• www.sialis.org
• www.nabluebirdsociety.org