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SAVE BLUEBIRDS BY HOSTING BLUEBIRD HOUSES

by Vicki Johnson
bluebird

Bluebird nesting habitat has been depleted as humans steadily clear trees from land to make way for houses, towns, shopping malls, highways and agriculture. Across the United States, old trees that provide natural cavities for bluebird nests have been cut down, limiting the habitat for all three species of bluebirds – Eastern Bluebirds, Western Bluebirds and Mountain Bluebirds.

In the earlier years of agriculture, wooden fence posts provided bluebird nesting cavities, but most wooden posts have either been replaced by metal posts or removed altogether.

Bluebirds were common in the United States until the mid-1800s.  But, in 1850, the house sparrow was introduced from Europe, followed by further competition for American bluebirds when the European Starling was brought to the United States in 1890, according to the Northern Prairie Wildlife Research Center. Both European species, which compete with bluebirds for habitat, spread quickly. These aggressive birds usually win because the bluebird is much more timid. Bluebirds are forced out of their nesting sites and often killed.

By 1900, the numbers of bluebirds was dwindling because of the loss of habitat and competition from the European birds. In the 1930s, a few people began to use bluebird nesting boxes to provide nesting sites. By the 1970s, more Americans recognized the tremendous need. Bluebird boxes are given credit for having a significant impact on the return of bluebird populations. But their continued use is needed.

You can help bluebirds find nesting sites in your backyard by erecting bluebird houses and monitoring them throughout the nesting season. Whether you have room for one or two bluebird boxes or several acres available for a bluebird trail – a string of boxes along a specific route - you can help provide nesting sites.

Bluebird habitat is a key factor to consider. Open rural country with scattered trees and low or sparse ground cover is best. Suitable habitat should include perch sites, such as a fence line, wires or tree branches where bluebirds may perch to search for food. If you don't have backyard space available, the owners of open spaces are often agreeable to letting you put up bluebird boxes. Good places to check include pastureland, parks with open grassy areas, and mowed areas such as cemeteries and golf courses.

You can buy kits to assemble bluebird boxes yourself, buy pre-assembled bluebird boxes, or check with your local conservation organizations.

Mount nesting boxes so the entrance hole is approximately 5 feet above the ground. If possible, face the box away from prevailing winds and toward a tree or shrub about 100 feet away. Trees and shrubs provide a landing spot for the young bluebirds when they first leave the box.

The distance between boxes varies, but general guidelines are 100 yards apart for Western Bluebirds, 150 yards apart for Eastern Bluebirds and 300 yards apart for Mountain Bluebirds. Check with your nearest bluebird association or department of natural resources for recommendations in your area.

Sometimes it's beneficial to mount bluebird boxes in pairs between 5 and 25 feet apart – especially in areas where tree swallows are common. Different species usually don't mind nesting near each other and the boxes can lessen competition and provide nesting sites for both species.

The size of the hole where a bluebird enters a nesting box is important and varies by species – generally about 1¼ inches. A bluebird box should be well ventilated, watertight, have drainage holes, be easy to monitor and easy to clean.

But assisting bluebirds requires more than providing nesting boxes. Don't put up a blue bird box if you do not plan to monitor it. Boxes must be checked at least once a week during the nesting season. House sparrow nests must be removed as soon as they're discovered. However, there are other species of cavity nesters, such as the tree swallow, that may use bluebird boxes and should not be removed.

Here are some general guidelines for monitoring bluebird boxes:

  • Do not open a box after nestlings are 12-14 days old. Doing so could result in the nestlings leaving the box before they are able to fly, greatly reducing their chance of survival.
  • Have bluebird boxes in place by mid-March when bluebirds return from their winter migration and are looking for nesting sites. However, boxes may also be put up later in the nesting season. Blue birds usually nest in April and May. In southern states, where bluebirds reside year round, nesting may occur earlier.
  • Learn to recognize a bluebird nest – a cup-shaped nest usually made up totally of woven grass and sometimes pine needles. Eggs in a bluebird nest are light blue. There are usually four or five eggs.
  • After hatching, nestlings remain in the nest 18 to 21 days before they fledge (leave the nest). Nests should be removed from the boxes as soon as the young birds have fledged.
  • Don't be discouraged if bluebirds do not use your boxes in the first year or two. Especially if bluebirds are not common in your area, it can take a while before the birds find the nesting habitat.
  • Keeping written records of the activity in your box(es) can help the North American Bluebird Society, a non-profit organization, compile data on bluebird populations in North America. Annual Nesting Report Forms are available from the bluebird society.
  • For bluebird house plans and specifications in your area and a wealth of other information about helping to save bluebirds, visit the North American Bluebird Society website.

Additional information is available from birding hobbyists, such as: how to attract Eastern Bluebirds, bluebird preservation do's and don'ts, and how to attract cavity nesting songbirds (including bluebirds).