Many people enjoy these beautiful "Gems of Blue," and want to take an active role in helping them increase in numbers. Bluebird numbers were once decreasing rapidly throughout the country due to loss of habitat and competition for dwindling nest sites from the European starling, house sparrow, and other cavity-nesting species. In the 1940s, T.E. Musselman of Quincy began to try attracting bluebirds to artificial nest boxes in order to help stop their decline. Luckily, the birds responded. Musselman's work was taken up by many others who wanted to help this beautiful and demure thrush make a comeback. Today, there are bluebirders throughout the U.S. and Canada, and bluebird trails stretch for miles across prime habitat.

To aid our bluebirds in Illinois, the Illinois Bluebird Project makes materials available on loan to Forest Preserve and Conservation Districts, 4H clubs, Girl Scout and Boy Scout troops, and other interested groups for planning bluebird workshops. These include a bluebird video, educational packet and bluebird nestbox plan for making kits for a workshop. For information on borrowing a bluebird education kit, please contact the IAS Office.

Bluebird Boxes: Who Uses Them?
While every bluebirder hopes for bluebirds in every box, chances are that some will be occupied by other species, such as chickadees, tree swallows, house wrens, and house sparrows. Occasionally, even a white-footed mouse, ants, wasps, or a bat will lay claim to one! While a few chickadees and tree swallows are nice additions to the bluebird trail, the wrens and sparrows are not so nice. These two species are aggressive, and will destroy bluebird eggs and take over the next boxes for themselves.

Proper placement of nest boxes will avoid some problems with wrens and sparrows. If the box is placed too close to a wooded or brushy area, house wrens may be attracted. If the nest box is too close to a shed, barn, or other structure, house sparrows may find it perfect for their nests. Bluebirds prefer more open areas, with short grass nearby for hunting insects. The nest box should be placed several feet from any trees or shrubs, and the hole should be facing away from them.

Bluebird Boxes: Which is Best?
There are many designs for bluebird boxes, with more "experimental" ones being tested each season. Some monitors prefer the Peterson box, while others do not like it. Regardless of design, a few basics are important: the size of the hole should be I and 1/2 inches in diameter, and located 8 inches from the floor of the box. The floor of the box should be 4 1/2 to 5 1/2 inches square. The box should be accessible for monitoring and cleaning. Most monitors favor side or front-opening boxes rather than those opening from the top. The roof should be slanted, and should overhang the box by about 2 inches to provide shade and keep rain from the hole. The box should have ventilation/drainage holes. Some kind of predator guard is important to keep raccoons from reaching in to get eggs, young, or even adult birds on the nest. The box should not have any kind of perch—this encourages wrens and sparrows. For plans and box designs, join IBP and get this information and more in our newsletter!

Trouble in Paradise: When Things Go Wrong ...
Bluebirds are not always successful in raising young. Predators may destroy eggs or young before they are fledged. Common predators include raccoons and black rat snakes, both of which will learn where boxes are and return to them. Because snakes are excellent climbers, nest boxes should never be fastened on trees. The best way to prevent predation by raccoons and snakes is to attach a baffle to the post which supports the bluebird box.

House wrens and house sparrows may enter the boxes and destroy the eggs or kill young. Usually, they then construct their own nests over the top of the bluebird nest. House sparrow nests and eggs can be removed, since these birds are not native and are not protected by law. House wrens are native songbirds and their nests and eggs are protected. However, wrens often build "dummy" nests consisting only of twigs. They will sometimes fill an entire nest box with twigs, thus keeping bluebirds or other cavity-nesting birds from building in the box. Dummy nests can be removed, since they are not actually used by the wrens. Sometimes, it is necessary to block the entry hole for a few days to discourage wrens or sparrows from returning to the nest box.

Young bluebirds are sometimes the victims of parasites. Ants, lice, mites and fleas can be a problem, but they are seldom found in boxes that are mounted properly on metal poles out in the open. Dusting nest boxes with sulfur can help with these problems. Other methods include putting a Teflon coating (spray or tape) or smearing a band of STP Oil Treatment around the pole. Another problem parasite is the blowfly, which lays its eggs in the nest. The larval maggots suck the blood of the nestlings. Unless the nestlings are weakened by a lack of food or some other factor, however, the parasitism is not usually fatal. The use of rotenone or other supposedly "safe" pesticides IS NOT recommended. The blowfly pupae are parasitized by a tiny wasp, which would also be killed by any pesticide used, thus reducing the effectiveness of a natural predator on the blowfly population.

Bluebird monitors across the state are encouraged to send their data at the end of each season to the address below:

Mary Hennen
Bird Division, Field Museum
1400 S. Lake Shore Drive
Chicago, IL 60605
312-665-7718
hennen@fieldmuseum.org

IBP Committee Members: They will answer questions!

For more information on any IAS projects, please contact our Danville office at 217-446-5085 or fax 217-446-6375.

• Illinois Bluebird Project
  
  
• Stamps For Wildlife Habitat
  
  
• Landowner Bird Survey Program
  
  
• Bird & Butterfly Backyard Sanctuary Program
  
  
• Habitat Savers Program