Nest Boxes

Nest Boxes

If you wish to attract birds to your yard, placing bird houses targeted to the species you wish to court is a good idea. As the table below indicates, a given species of bird has distinct preferences in terms of size and depth of the box as well as the size of the entrance hole and how far above the floor of the box as well as how high above the ground it is placed.

In general only cavity nesting birds are attracted to boxes. Robins will use a man made ledge, which can be considered a bird house. Birds like Mockingbird, Cardinal, Blue Jay that build woven nests in the canopy will not be attracted to a bird box.

Because of the fastidious nature of city and suburban folks, many of the dead trees that would provide nesting cavities for birds are removed thus, depriving this group of birds a home. By providing man made bird houses you are contributing to the conservation of these species.

Bird House Specifications

Species	Cavity Floor	Cavity Depth	Entrance above floor	Entrance diameter	Height to place box	Location to place box
	inches	inches	inches	inches	feet
Barn Swallow	6x6	6	#	#	8-12	Attach to building
Barn Owl	16x17	20***	5.5	6x6	8-20	On building/pole
Bluebird	5x5	8	6	1 1/2	5-10	Open grassy area
Bewick's Wren	4x4	6-8	1-6	1-1 1/2	6-10	Woodland edge
Carolina Wren	4x4	6-8	1-6	1 1/2	6-10	Woodland edge
Chickadee	4x4	8-10	6-8	1 1/8	6-15	Woodland edge
Downey Woodpecker	4x4	8-10	6-8	1 1/4	6-20	Woodland edge*
Flicker	7x7	16-18	14-16	2 1/2	6-20	Woodland edge**
Grt.-crested Flycatcher	6x6	8-10	6-8	2	8-20	Open woods/orchard
Hairy Woodpecker	6x6	12-15	9-12	1 1/2	12-20	Woodland edge*
Nuthatch, species	4x4	8-10	6-8	1 1/4	12-20	Woodland edge
Phoebe	6x6	6	#	#	8-12	Near water & woods
Prothonotary Warbler	4x4	8	5	1 1/2	4-7	Near water
Purple Martin	6x6	6	1	2 1/2	15-20	Open area
Red-bellied Woodpecker	6x6	12-14	10-12	2 1/2	12-20	Woodland edge*
Red-headed Woodpecker	6x6	12-15	9-12	2	12-20	Woodland edge*
Robin	6x8	8	#	#	6-15	Side of building/tree
Screech Owl	8x8	12-15	9-12	3	10-30	Edge or open woods
Sparrow Hawk	8x8	12-15	9-12	3	10-30	Pasture
Titmouse	4x4	8-10	6-8	1 1/4	6-15	Woodland edge

*Cover the floor of the box about 2 inches deep in wood chips.

**Fill the box with wood chips. Flickers need to feel that they are excavating a nesting cavity so they need wood chips to remove.

***Back panel is 20" high while front is only 15" high.

#One or more sides of the house are left open so the house is essentially a covered ledge for the bird to build a nest on.

The picture on the right shows a typical house build according to the directions for a Bluebird. The wood used was from an old cedar fence. Cypress wood is the most durable but hard to find. One should not use pressure treated wood intended for decking since the arsenate preservative could be toxic to the chicks. This picture also shows the original 1 1/2 inch hole greatly enlarged by a flicker. This can be prevented by surrounding the entrance hole with a piece of metal flashing.

In constructing your bird house the following points should be considered:

	Provide ventilation by drilling quarter inch holes in the side of the box just under the roof line. Holes in the bottom of the box are also beneficial for drainage.
	Use rust resistant screws to assemble the box.
	Construct the box so that the roof or one side can be easily removed for cleaning the box of old nests.
	Mount the box so the entrance is not facing into the prevailing wind and it does not receive the hot afternoon sun, which could cook the nestlings.
	Mount the box in a location where it is protected from predators such as black snakes, cats and squirrels. It is wise to place metal flashing around the pole or tree the box is on so that predators can't climb to the box.
	Since birds are territorial do not place more than one kind of box for attracting a given species in the average city size yard. It is fine to have several boxes, but they should be designed to attract different species.
	Remove house sparrow and starling nests and eggs from your boxes. These species are not protected. They out-compete native birds for nesting sites and are detrimental to native species.
	Do not put a perch on the front of the house. It is not needed and only encourages house sparrows.
	Put the house up in the late fall or early winter for use the following spring.

Rustic Houses

More natural style houses can be constructed from hollow tree limbs as shown in the picture. The hollow tree limb is cut the required height, a proper size hole drilled using a drill bit made for cutting out lock holes in doors. A top and bottom are screwed on and then the house is mounted by attaching a 1x2 to a flattened edge of the house. The whole assembly is then attached to a tree/post via the 1x2.

One can also split a small log then hollow out the two pieces with a chain saw or chisel. Use a metal hinge to join the two hollowed out pieces. Bore an entrance hole and put a roof on and attach the box to a support of choice. Do not hollow out all the way through the log so that you will have a bottom to the cavity.

Gourds are a good substrate for bird houses. First allow the gourd to fully dry out until you can hear the seeds rattle when the gourd is shaken. Drill an entrance hole in the gourd and remove all the seeds and other stringy plant material. Mold can be removed with chlorox/detergent solution with some scrubbing. Rinse well, allow to dry thoroughly and then paint the outside. Drill drainage holes in the bottom and hang at the proper height. The gourd should be prepared several months before its intended use to allow time for thorough drying.