Some Rules for Making and Erecting Bird Boxes.—Here are a few simple rules on the making and placing of bird boxes:
1. In all nest boxes, except those designed for Martins, the opening should be several inches above the floor, thus conforming to the general plan of a Woodpecker's hole, or natural cavity in a tree.
2. As a rule nest boxes should be erected on poles from ten to thirty feet from the ground, or fastened to the sides of trees where limbs do not interfere with the outlook. The main exception is in the case of Wrens, whose boxes or gourds can be nailed or wired in fruit trees or to the side of buildings.
3. Martin houses should be erected on poles at least twenty feet high, placed well out in the open, not less than one hundred feet from buildings or large trees.
4. All boxes should be taken down after the nesting season and the old nesting material removed.
Size of Bird Boxes.—As to the size of nesting boxes for various species, and the diameter of the entrance hole, I cannot do better than give the dimensions prepared by Ned Dearborn, of the United States Department of Agriculture, Washington, D. C.
DIMENSIONS OF NESTING BOXES
Species Floor Depth Entrance Diameter Height
of of above of above
cavity cavity floor entrance ground
_Inches Inches Inches Inches Feet_
Bluebird 5 by 5 8 6 1 1/2 5 to 10
Robin 6 by 8 8 [1] [1] 6 to 15
Chickadee 4 by 4 8 to 10 8 1 1/8 6 to 15
Tufted Titmouse 4 by 4 8 to 10 8 1 1/4 6 to 15
White-breasted
Nuthatch 4 by 4 8 to 10 8 1 1/4 12 to 20
House Wren 4 by 4 6 to 8 1 to 6 7/8 6 to 10
Bewick Wren 4 by 4 6 to 8 1 to 6 1 6 to 10
Carolina Wren 4 by 4 6 to 8 1 to 6 1 1/8 6 to 10
Dipper 6 by 6 6 1 3 1 to 3
Violet-green
Swallow 5 by 5 6 1 to 6 1 1/2 10 to 15
Tree Swallow 5 by 5 6 1 to 6 1 1/2 10 to 15
Barn Swallow 6 by 6 6 [1] [1] 8 to 12
Martin 6 by 6 6 1 2 1/2 15 to 20
Song Sparrow 6 by 6 6 [2] [2] 1 to 3
House Finch 6 by 6 6 4 2 8 to 12
Phoebe 6 by 6 6 [1] [1] 8 to 12
Crested
Flycatcher 6 by 6 8 to 10 8 2 8 to 20
Flicker 7 by 7 16 to 18 16 2 1/2 6 to 20
Red-headed
Woodpecker 6 by 6 12 to 15 12 2 12 to 20
Golden-fronted
Woodpecker 6 by 6 12 to 15 12 2 12 to 20
Hairy Woodpecker 6 by 6 12 to 15 12 1 1/2 12 to 20
Downy Woodpecker 4 by 4 8 to 10 8 1 1/4 6 to 20
Screech Owl 8 by 8 12 to 15 12 3 10 to 30
Sparrow Hawk 8 by 8 12 to 15 12 3 10 to 30
Saw-whet Owl 6 by 6 10 to 12 10 2 1/2 12 to 20
Barn Owl 10 by 18 15 to 18 4 6 12 to 18
Wood Duck 10 by 18 10 to 15 3 6 4 to 20
[1] One or more sides open.
[2] All sides open.