Introduction

 

The bluebird has always been one of the most popular birds in North America.  It is loved for its beautiful coloring, pleasing voice, and gentle disposition. The bluebird is the symbol of love and happiness in many songs.

 

The bluebird was once numerous even in urban residential areas.  It has sadly seen quite a decline in numbers, with the eastern bluebird population declining to 90% since the early 1900s.  A number of factors, including insecticides, habitat destruction, predators and competition from non-native species have contributed to this decline.

 

Bluebirds are primarily insectivores and eat many insects that we consider to be pests: cutworms, grasshoppers and flying insects.  They supplement this diet in fall and winter with wild berries and are in danger of starving if snow covers the ground and berries are unavailable.  Many people hope bluebirds will be attracted to a winter feeder filled with peanut butter mix, chopped dry fruit and peanut kernels.

 

Bluebirds prefer to inhabit fields and open woodlands.  Their hunting strategy is to wait on a low perch and then attack, meaning an area with suitable perches is preferred.  Bluebirds are strict cavity nesters.  With a shortage of natural nesting cavities (standing dead trees or rotting fence posts), man made nesting boxes are necessary.  Those trying to save the bluebird have begun a massive effort by erecting thousands of nesting boxes that are specifically designed for bluebirds and are predator and competitor proof.

 

Species

 

There are three species of bluebird: eastern, western and mountain.  They are all members of the thrush family.  The eastern bluebird is bright blue with a rusty red breast and breeds in every state east of the Rocky Mountains. The western bluebird has a blue throat with red color extending to its upper back and breeds in western states from Canada to Mexico and east to Colorado. The mountain bluebird is entirely blue with a white underbelly and breeds in the Northwest east to the Dakotas and north into Alaska.

 

Courtship

 

The spring courtship rites of the bluebird are among the most enjoyable to witness.  The male selects a nesting cavity and devotes all of his energy to luring a female to it with his song.  He sings and sings, as the female sits passively by, enjoying his effort.  When she inspects the nesting place, he interprets her interest as acceptance and his song becomes even more passionate.  The final selection of the nesting place however, is hers.  If she finds his choice unacceptable, he must search for something better.

 

Nest Building

 

The female builds a nest of dry grass or pine needles and other plant material.  The nest is typically about three or four inches deep.  Here the eastern bluebird lays an average of three to five clear blue eggs (though occasionally they may be white).  The western and mountain species are apt to lay one or two more than the eastern.  The eggs hatch in two weeks and the young are ready to leave the nest in 15 to 20 days, ready to fly and soon able to feed themselves.

 

If given a clean nest box after each brood has fledged, by fall a pair may well have raised two or three broods.  They will then migrate south when the food supply runs out or it gets too cold.

 

Competition

 

The bluebird's chief competitors are the English house sparrow (introduced to the US in 1851) and the European starling (introduced to the US in 1890).  House sparrows nest early and often take the best bluebird nesting sites first.  Sparrows will break the bluebird's eggs in a nest or even peck baby or adult bluebirds to death.  Sparrows may take over a bluebird nest in winter when the bluebirds have migrated south.  Starlings nest later in the season, but are quite aggressive and, being larger than bluebirds, can easily take over any bluebird nest cavity they wish to.  Starlings may drive bluebirds out of an entire area and occupy every available nesting cavity, unless people intervene. 

Nests of sparrows, starlings and other competing species must be cleaned out of your bluebird house on a regular basis.

 

Tree swallows often find bluebird houses to their liking as well.  This problem can be lessened by hanging two houses close to each other or even back to back on a post.  Two bluebirds will not nest close to each other, so this gives the swallows one house and the bluebirds the other.  Swallows will even help protect the bluebirds from other competing birds.

 

How to Help

 

What can we do to assist the survival of this lovely bird?  We can provide suitable habitat, food, water, nesting cavities and winter shelter.  Plants that carry berries through the winter (holly, privet, honeysuckle, bayberry, sumac, bittersweet, hackberry, dogwood and others) will provide food for bluebirds and many other species.  Winter roosting boxes provide important shelter for many birds in winter.  Bluebirds may stay all year in areas where they can find sufficient food and a roosting box will help them maintain warmth on the coldest nights. Specifically designed nesting boxes, with features that favor the bluebird and discourage both predators and competitors, are required in order to give the bluebird a safe place to rear its young.

 

Bluebird Trail

 

What is a "Bluebird Trail?"  A bluebird trail can be created by hanging many bluebird houses in an area, about 100 yards apart, to give the bluebirds an abundance of housing.  They are often placed on fence posts, giving the appearance of a "trail." 

 

For best success with your bluebird nesting box, place it in an open area with scattered trees, particularly with low branches for bluebirds to perch on and watch for insects.  Pastures, parks, large lawns and golf courses are good locations for bluebirds.  Heavy ground cover will interfere with their ability to find insects.  Place nesting boxes where insecticides are not used.

 

The best height for a bluebird nest box is three to five feet above the ground.  Lower makes predation easier.  Higher tends to attract more sparrows.  The nest box should face a tree or shrub within about 50 feet, so that young may find a perch safe from predators when they leave the nest.  It should also face away from prevailing winds to prevent rain from driving through the entrance hole.  An east facing is generally best.

Fence posts make convenient locations, as do utility poles and even mail boxes (facing away from the road).  A predator guard on the post will help discourage predators.

 

Coveside Bluebird Houses

 

The construction of your Coveside bluebird house is based on years of research into the habits and preferences of bluebirds as well as the hazards that threaten their existence.  Coveside makes ten different models of bluebird house: Eastern Bluebird House, Western/Mountain Bluebird House, Sparrow-resistant Bluebird House, Observation Bluebird House, Horizontal Bluebird House, Slant-front Bluebird House, Open-top Bluebird House, Open 2-side Bluebird House, Economy Trail Box and Eastern Bluebird House Kit.

 

Coveside's nesting boxes are constructed of one-inch thick sustainably grown eastern white pine in order to provide adequate insulation from heat.  Most young birds that die in the nest do so because of heat and inadequate insulation from it.  Our lumber is custom milled with a "rougher head" finish, which allows fledglings a foothold when they are ready to climb out of the nest.

 

Ventilation is provided for at the top of each side panel.  The slanted roof overhangs the entrance hole to provide appropriate drainage.  The floor has drainage at all four corners and is recessed to keep it dry.

 

Coveside's nesting boxes are not painted or stained.  Over time they will weather, darken, turn gray and eventually blend right in with their environment.  Birds prefer an inconspicuous nest box.  The most important thing you can do to preserve the long life of this nesting box is to clean it out after each nesting cycle.  The side panel tilts out from the bottom for easy cleaning after the young have left the nest.  A latch at the bottom secures the panel in place.

 

If you paint or stain, it is critical to use water-based stain or paint only.  Oil-based paints and stains are toxic to birds.  A light seasonal external coating of boiled linseed oil is a highly effective non-toxic preservative.

 

Mounting instructions

 

Put a screw or nail into a tree or post at a height of three to five feet, leaving  about 1/4" sticking out.  Place the metal hanger at the top/rear of the nest box over the screw or nail.  (A few of our models do not include hanger brackets and are mounted directly through the rear wall of the nest box.)  Place a second nail or screw at the bottom of the back panel of the nest box to hold it securely.

 

Copyright Coveside Conservation Products 2009