Species-Specific Management (SSM)

Bluebird

Bluebird populations (Sialia sialis) dropped drastically over many years but they seem to have staged a comeback, partially as a result of changing land use practices and local nest-box projects. There has been much work done in New York State where the bluebird is the state bird. There is still much that can be done to increase the number of bluebirds in the open areas, road sides, and new forests of the southern Appalachians. The Virginia Bluebird Society is another contact

A Species Overview

1. Bluebirds prefer open areas with low vegetation. They are not birds of the forest but the forest opening and edge. Usually, the sparser the vegetation, the better the habitat.
2. Open woodlands of pines and oaks provide suitable perches, as do orchards, and some pastures.
3. They need include perches, sparse ground cover, and an abundance of insects, a large percentage of which are visible, not covered in shrubbery or under leaves and grasses.
4. Preferred food is moderately sized (10 - 30mm) insects. Beetles, grasshoppers, and spiders seem preferred.
5. One of the most critical factors limiting bluebird distribution is availability of nesting sites.
6. Bluebirds are territorial (they defend an area against other bluebird competitors).
7. Eastern bluebirds in the Virginia area migrate little due to the mild winters. If they do migrate of shift areas, they move southward until they find a suitable food supply and avoid heavy snows.

Management for Nesting Sites

Nests contain 5-6 eggs. Nests are usually of dry grass or pine needles. Eggs are blue.The incubabtion period is 14 days. Young leave in 18-21 days. Do not monitor nest after day 12 (avoid disturbance of young fledgings.) 3 sets of eggs may occur in one year.

There are a few methods to help improve possible nesting sites:

1. Stop using metal fence stakes and instead go back to using wooden fence posts.
2. Stop the practice of felling dead trees and leave them as a possible source for nest cavities.
3. Manage for woodpeckers. These results benefit bluebirds in the creation of nesting cavities by woodpeckers as they forage for food.
4. Fortunately, bluebirds readily accept artificial nesting cavities. Thus, putting well-designed bluebird boxes in suitable habitats is another method of improving cavity nesting sites.
5. Place the nesting boxes using the following criteria:
   • Use wooden boxes (over metal ones)
   • Place boxes at least 100 meters apart,
   • Use light colored exteriors
   • Have floor area less than 137.5cm²
   • Place them 1.5 meters (4 to 6 feet) off the ground (cutting down on competition from house sparrows and many bird species that prefer boxes higher than this above the ground)
   • Do not place them on a tree
   • Place in conspicuous areas in open fields and pastures,
   • Place in areas with short grasses and vegetation,
   • Place within 45 to 50 meters of low lying branches or perches,
   • Place near water resources, and
   • Place near food resources (plants with fleshy fruits).
6. Monitor and reduce competitors (Federal law may protect nests of tree swallows and wrens)
7. It is important to cut an entrance hole of 1.5-inches in diameter. This makes the hole large enough for bluebirds, but too small for most competing bird species. A new "slot" for boxes replacing the hole is now available.
8. Placing two boxes back to back also helps cut down on competition from other bird species. What usually happens is that the bluebird pair will chose one box and the competing bird species will chose the other.
9. Cutting boxes that are extra deep helps keep the predator from being able to reach in the hole and down into the nest.
10. Place a 1.5- inch thick block of wood around the hole to make the reach into the box longer for the predator.
11. Sheet metal nailed on as a covering over the wooden post or a sheet metal cone nailed to the wooden post under the box will prevent predators from climbing the post to get at the nesting box.
12. Having a 3-inch overhang of the roof away from the front of the box keeps predators from being able to reach in the entrance hole of the box.
13. Insulate nest boxes in winter by plugging up large holes and applying weather stripping at ventilation areas.
14. Cleaning the old nests out of the box at the end of the breeding season helps keep the parasite called the blowfly under control. Replace nesting material in boxes with new grass nests when nestlings are 5 days old.

Other Management Suggestions

1. Use mechanical mowing methods to keep grasses and other vegetation low.
2. Use prescribed burning to keep vegetation low.
3. Create small clearings (2 to 2.5 ha) and leave dead trees for nesting purposes.
4. Reduce the use of insecticides in backyard gardens or roadsides or switch to organic gardens to allow for increases in insects such as grasshoppers.
5. Plant or favor the following fruit bearing vegetation for summer and winter consumption:
   • Blueberries (Vaccinium spp.),
   • Honeysuckle (Lonicera),
   • Sumac (Rhus typhina),
   • Redcedar (Juniperus virginiana), and
   • Poison ivy (Rhus radicans).
6. Citizens respond well to requests to placing nesting sites.
7. Recruiting interest groups like the North American Bluebird Society or scouting groups to assist in establishing nesting box trails, maintaining them, and offering hikes to birdwatchers.
8. Keep records of progress in management birds seen and heard along standard routes, nests occupied, and visitors attracted to allow improvements in time- and cost-effectiveness.

See the North American Blue Bird Society and the Virginia Blue Bird Society

Contributions by Karen A. Blakney-Ross (1996), Timothy E. Dorrell (1991), and Brett Luce (1992)

Submitted by Robert H. Giles, Jr.

This Web site is maintained by R. H. Giles, Jr.
Last revision January 17, 2000.