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. {223} The foregoing list does not contain the names of all the kinds of birds which have thus far been induced to occupy these artificial nesting sites, but it has most of them. It should be remembered that hole-nesting birds are the only kind that will ever use a bird box. One need not expect a Meadowlark to leave its nest in the grass for a box on a pole, nor imagine that an Oriole will give up the practice of weaving its swinging cradle on an elm limb to go into a box nailed to the side of the tree.