few species that appreciates an
open, mowed yard with scattered
Some species, such as robins
and swallows, prefer a ledge
rather than a cavity for nesting.
Putting up a simple shelf about
6" by 8" may encourage them to
nest in your yard.
If it is in an area of human
activity, a slightly larger platform
below the shelf will catch
droppings and be easy to clean.
The nesting shelf should have a
roof, or be placed so that another
structure provides protection
from rain and hot sun.
Wherever you attach your
nesting boxes, they need to be
secure, even in high winds. The
birds should have a clear path to
the entrance, and a perch within
15' for resting and checking for
Many of our favorite songbirds
build the familiar cup-shaped
nests that we find abandoned in
the fall but, as with everything
else, these exhibit many different
characteristics. Some are woven
with an intricacy that amazes us,
while others are amazing only
because they manage to hold
Building Materials For Birds
Often the availability of
materials determines what is
used in construction. We can
encourage nesting by offering
"short cuts," filling a mesh onion
bag with lengths of string or yarn
(no longer than 8" for safety),
pet fur, human hair, soft strips of
cloth, and even dryer lint.
Hanging it near likely nesting
spots will save the birds both
time and energy. Place small
twigs and bits of bark in a pile for
the same purpose. Species such
as robins which use mud to
strengthen their nest will
appreciate a pan of moist dirt.
Unlike territorial species,
purple martins enjoy living in
close quarters. They are a
challenge to attract and require
a unique type of house. The
commercial aluminum models are
the only metal houses
recommended for birds.
If you build your own from
wood, good air circulation is
critical, and each nesting
compartment needs to be the
right size. A balcony with a 2"
high fence around each level of
the house will keep fledglings
from falling out.
Dividers on the balconies
between the entrance holes keep
older chicks from joining younger
ones and out-competing them
for food. Ideally, the house
should allow new levels to be
added as the colony grows.
It needs to be placed in the
open, at least 40' from any tree
or structure, although purple
martins like utility wires within
30' to use as perches.
Covering the entrances after
the birds migrate keeps
sparrows and starlings out.
Purple martins are the largest
North American swallow and will
reward your efforts by eating
huge quantities of insects.
Although it is illegal to
interfere with or harm any native
birds (with the exception of
licensed hunting periods), non-
native species don't enjoy this
protection. Two in particular need
to be mentioned: European
starlings and English (or "house")
They are extremely aggressive
and frequently take over nesting
sites from native birds, often
killing the parents and babies.
When monitoring nest boxes,
you are advised to remove the
nests of these birds as soon as
Both species build loose, messy
nests, so they are usually easy to
identify. While you may find it hard
to take this step, remember that
these species can literally
eliminate some of the native birds
in your area by taking over all of
the available nesting sites.
Bluebirds are particularly at
risk, and often need human
This article was written by
Maryland Master Wildlife Habitat
Naturalist Cathy Gilleland.
For more information or for the
name of a Master Wildlife Habitat
Naturalist in your area, please
WindStar Wildlife Institute
10072 Vista Court
Myersville, Maryland 21773
WindStar Wildlife Institute is a
national, non-profit, conservation
organization whose mission is to
help individuals and families
establish or improve the wildlife
habitat on their properties.
"Birds, not rooted to
the earth, are among
the most eloquent
expressions of life."
- Roger Tory Peterson