_Birds You Can Attract to Nest Boxes_
Many of the birds that visit feeders and baths may stay and nest in
nearby trees. Most of them, including cardinals, doves and orioles,
don’t nest in boxes. You can still help them by considering their food
and shelter requirements in your landscape plans.
More than two dozen North American birds nest in bird houses. The
following descriptions will help you determine which birds might visit
your neighborhood.
_Bluebirds_
If you put up a bluebird house near an old field, orchard, park,
cemetery or golf course, you might have a chance of attracting a pair
of bluebirds. They prefer nest boxes on a tree stump or wooden fence
post between three and five feet high. Bluebirds also nest in
abandoned woodpecker nest holes.
The most important measurement is the hole diameter. An inch and a
half is small enough to deter starlings, which, along with house
sparrows, have been known to kill bluebirds, as well as adults sitting
on the nest. Bluebirds have problems with other animals too.
Discourage cats, snakes, raccoons and chipmunks by mounting the house
on a metal pole, or use a metal predator guard on a wood post.
_American Robins_
The robin is our largest thrush. They prefer to build their nest in
the crotch of a tree. If you don’t have an appropriate tree, you can
offer a nesting platform. Pick a spot six feet or higher up on a
shaded tree trunk or under the overhang of a shed or porch. Creating a
“mud puddle” nearby offers further enticement, as robins use mud to
hold their nests together.
_Chickadees, Nuthatches and Titmice_
Chickadees, titmice and nuthatches share the same food, feeders, and
habitat. If you put a properly designed nest box in a wooded yard, at
least one of these species might check it out.
Put chickadee houses at eye level. Hang them from limbs or secure them
to tree trunks. The entrance hole should be 1⅛ inches to attract
chickadees, yet exclude house sparrows. Anchor houses for nuthatches
on tree trunks five to six feet off the ground.
[Illustration: Titmouse house]
_Brown Creepers and Prothonotary Warblers_
Look for brown creepers to nest behind the curved bark of tree trunks.
In heavily wooded yards, slab bark houses appeal to creepers.
Prothonotary warblers also prefer slab bark houses, or bluebird boxes
attached to a tree trunk, but theirs must be placed over water (lakes,
rivers or swamps) with a good canopy of trees overhead.
_Wrens_
Wrens don’t seem to be very picky about where they nest. Try nest
boxes with a 1 inch × 2 inch horizontal slot (1½ inch × 2½ inch for
the larger Carolina wrens) instead of a circle. These are easier for
the wrens to use. However, the larger the opening, the more likely it
is house sparrows will occupy the box.
Wrens are known for filling a nest cavity with twigs, regardless of
whether they use the nest to raise their young. Since male house wrens
build several nests for the female to choose from, hang several nest
boxes at eye level on partly sunlit tree limbs. Wrens are sociable and
will accept nest boxes quite close to your house.
[Illustration: Inside of nesting cavity]
_Tree and Violet-green Swallows_
Tree swallows prefer nest boxes attached to dead trees. Space the
boxes about seven feet apart for these white-bellied birds with
iridescent blue-green backs and wings. The ideal setting for these
insect-eaters is on the edge of a large field near a lake, pond or
river.
Violet-green swallows nest in forested mountains of the West; boxes
placed on large trees in a semi-open woodland will attract them.
_Barn Swallows and Phoebes_
If you have the right habitat, like an open barn or old shed, barn
swallows and phoebes are easy to attract. It’s their nesting behavior,
not their plumage or song, that catches your attention. However, these
birds tend to nest where you would rather not have them: on a ledge
right over your front door. To avoid a mess by your door, offer the
birds a nesting shelf nearby where you’d rather have them.
[Illustration: Nesting ledge]
_Purple Martins_
Many people want martins in their yards because, it’s been said, these
birds eat 2,000 mosquitoes a day. While it’s true that they eat flying
insects, don’t expect purple martins to eliminate mosquitoes in your
yard completely. Martins prefer dragonflies, which prey on mosquito
larvae. If you want to help rid your yard of mosquitoes, put up a bat
roosting box. One bat can eat thousands of mosquitoes a night.
Martins are entertaining creatures, however, and you’ll enjoy watching
their antics in your backyard. You have the best chance of attracting
martins if you put a house on the edge of a pond or river, surrounded
by a field or lawn. Martins need a radius of about 40 feet of
unobstructed flying space around their houses. A telephone wire nearby
gives them a place to perch in sociable groups.
[Illustration: Ceramic house]
Martins nest in groups, so you’ll need a house with a minimum of four
large rooms—6 or more inches on all sides, with a 2½ inch entrance
hole about 1½ inches above the floor. Ventilation and drainage are
critical factors in martin house design. Porches, railings, porch
dividers and supplemental roof perches, like a TV antenna, make any
house more appealing.
You can also make houses from gourds by fashioning an entrance hole
and small holes in the bottom for drainage. If you use gourds, it’s
not necessary to add railings and perches. Adult martins will perch on
the wire used to hang the houses. Before you select a house, think
about what kind of pole you’re going to put it on. Martins occupy a
house ten to twenty feet off the ground. Some poles are less
cumbersome than others.
Gourd houses are the easiest to set up. String them from a wire
between two poles, from a sectional aluminum pole, or on pulleys
mounted to a crossbar high up on a pole.
You can mount lightweight aluminum houses for martins on telescoping
poles, providing easy access for maintenance and inspection. Because
of their weight (more than 30 pounds), wood houses should not be
mounted on telescoping poles. You’ll have to use a sturdy metal or a
wood pole attached to a pivot post. The problem with this lowering
technique is that you can’t tilt the house without damaging the nests
inside. If you put your house on a shorter, fixed pole, ten to twelve
feet high, you can use a ladder to inspect and maintain it.
_Flycatchers_
The great crested flycatcher and its western cousin, the ash-throated
flycatcher, are common in wooded suburbs and rural areas with
woodlots. Their natural nesting sites are abandoned woodpecker holes.
Flycatchers may nest in a bird house if it is placed about ten feet up
in a tree in an orchard or at the edge of a field or stream. This is a
longshot, but well worth the effort if you are successful.
_Woodpeckers_
You can attract all types of woodpeckers with a suet feeder, but only
the flicker is likely to use a bird house. They prefer a box with
roughened interior and a floor covered with a two-inch layer of wood
chips or coarse sawdust. Flickers are especially attracted to nest
boxes filled with sawdust, which they “excavate” to suit themselves.
For best results, place the box high up on a tree trunk, exposed to
direct sunlight.
Try building a birdhouse for the other species of woodpeckers
following the guidelines in this booklet. You might be surprised!
_Owls_
Most owls seldom build their own nests. Great horned and long-eared
owls prefer abandoned crow and hawk nests. Other owls (barred, barn,
saw-whet, boreal and screech) nest in tree cavities and bird houses.
Barn owls are best known for selecting nesting sites near farms. Where
trees are sparse, these birds will nest in church steeples, silos and
barns. If you live near a farm or a golf course, try fastening a nest
box for owls about 15 feet up on a tree trunk.
Screech owls prefer abandoned woodpecker holes at the edge of a field
or neglected orchard. They will readily take to boxes lined with an
inch or two of wood shavings. If you clean the box out in late spring
after the young owls have fledged, you may attract a second tenant—a
kestrel. Trees isolated from larger tracts of woods have less chance
of squirrels taking over the box.
[Illustration: Owl house]