Category: Boxes
Q:
"I want to mount a Bluebird box but do not know
where to begin."
A: Once you've
caught the ‘bluebird bug,’ it's difficult to resist these
beautiful creatures. However, bluebirds have quite specific
nesting requirements, so it is important to understand that
the keys to attracting bluebirds are placing properly
constructed nest boxes in suitable habitat.
Bluebirds are insectivorous during
the nesting season, feeding mainly on ground-dwelling
insects. Ideal bluebird habitats are open and barren or
short-cut/sparsely grassed areas (so they can see their
food) with a few trees nearby (for perching). Pesticide
and herbicide-free cattle or horse pastures, cemeteries,
acreages, abandoned orchards, hike-and-bike trails,
prairie coulees, lightly traveled roadsides, abandoned
railroad rights-of way, golf courses, open areas in
parks, the edges of meadows, clear cuts adjacent
to or within forested areas that have been recently
burned, and sagebrush flats provide excellent bluebird
habitat. Bluebirds will also nest on the fringes of
towns and cities, especially if they were nesting in
those areas prior to development
Poor bluebird habitat includes areas that they naturally
shun (i.e., city centers, densely wooded areas, or
intensively farmed areas where there is a lack of
natural habitat), areas where they are in competition
with House Wrens or House Sparrows, or locations where
the boxes are at risk of being subject to predation or
vandalized.
Q:
"How do I know if I have the right kind of nest
box for my bluebirds?"
A: There is no
one single perfect, ultimate bluebird nestbox. Dozens of
different nestbox designs are being used with equal success
by bluebird trail operators throughout North America.
Although styles and designs can vary, all boxes should
provide the birds with a safe and secure nesting site. If
possible, build or purchase a box that is NABS-approved.
The following are some tips for a good bluebird box:
-
The best materials for bluebird box
construction are 5/8 or 3/4-in. exterior grade plywood
or cedar. Redwood and pine boards can be used, but
redwood often splits when it dries so it should be
avoided in dry areas, and most boards will warp over
time. Do not use treated lumber or interior grade wood
(including OSB board). When possible, use scraps
salvaged from construction sites, or where it is
available, try to use environmentally sound certified
lumber from sustainable managed forests. Cardboard, plastic jugs,
milk cartons and large tin cans provide little
insulation (especially against heat) so should not be
used.
-
Bluebird boxes made from good
quality plywood do not need to be painted, but most
trail operators paint the outside of their boxes with a
good quality exterior paint (use non-leaded paint only)
or stain. Do not paint the inside or the inside of the
entrance hole). Use a neutral color in northern areas,
and a light colors in hot areas to reduce overheating.
-
Assemble the box with screws or
nails. Screws are more expensive, but they make
construction easier, and make it easier to replace
parts.
-
One panel (top, front or side)
should open to allow for monitoring and cleaning. Make
sure the panel fits snugly to prevent rain from blowing
in the seams.
-
If plywood or smooth boards are
used, place hardware cloth or etch shallow saw kerfs on
the inside of the front panel, just below the entrance
hole. Although young bluebirds are fairly adept at
exiting most boxes, this roughness provides an extra
toehold for them. If using hardware cloth, be sure the
material is pressed tight against the wood so the birds
won’t get a toe caught.
-
Perches encourage House Sparrows
and predators. Do not build or purchase a nestbox that
has a perch.
-
Dimension recommendations box are
as follows:
-
Entrance hole -
Eastern or Western Bluebirds: 1 1/2-in.; Mountain
Bluebirds: 1 9/16. In areas where overlap with
either use the larger entrance hole on all boxes.
Oval holes, measuring 1 3/8 in. x 2 1/4 in. are also
used with success in Peterson-style boxes.
-
Nestbox depth -
at least 7 in. (17.8 cm) from the bottom of the hole
to the bottom of the box. Shallow boxes put the
occupants at greater risk of predation.
-
Floor size
- Eastern and Western
Bluebirds: at least 4 x 4 in.; Mountain Bluebirds:
at least 5 x 5 in.
-
Roof overhang -
approximately 3 in. to provide shade, protect the
entrance hole from driving rain and to discourage
predators.
-
Ventilation -
the hotter the climate, the more ventilation should
be provided. Vent holes should be drilled near the
top of each sideboard (drill holes at an upward
angle to provide ventilation without allowing rain
to blow in). Use 1/2-in. holes in hotter regions,
1/4-in. holes in the north.
-
Drainage - cut
off a small amount of each corner of the bottom
board or drill 3/8- in. holes in each corner. The
floor of the box should be recessed ¼” to prevent
the floor from absorbing water.
To learn more about proper nest box construction, go to
Q: "Where and how
should I mount my box?"
A: Boxes should be
spaced at intervals of about 300 ft. If House Wrens are
likely to be a problem, be sure the box is mounted at least
200 feet away from a wooded or brushy area. If Tree
Swallows or Violet-green Swallows are likely to use the box,
try setting out two boxes about ten feet apart so that the
bluebirds can use one and the swallows the other. Most
bluebirders have found that this practice of pairing the
boxes will allow both species to nest side by side in
relative peace. Boxes should be mounted on a smooth metal
pole at a height that is convenient for monitoring and
maintenance. Bluebirds tolerate a box mounted as high as 15
feet and as low as 3 feet from the ground. However, a box
mounted lower than 4 or 5 feet is at greater risk of
predation. The nest box should be mounted so the entrance
hole is directed away from prevailing winds to reduce the
amount of rain that might be blown into the box. The box
opening should also face away from direct sun exposure. A
nearby tree provides young bluebirds both with a place to
fly to when they first leave the nest, as well as shelter
from the elements and predators. Boxes mounted along roads
should always face parallel with, rather than perpendicular
to, the road so that the birds (especially the fledglings)
are more likely to fly along the road ditch, rather than out
across the road and into the path of oncoming traffic.
For more information go to "Getting
Started."
Q: "OK, I've got my
box mounted. Now what?"
A: Monitoring
your box on a regular is very important, as it will enable
you to collect important scientific information (e.g., the
number of eggs, nestlings, fledglings etc.), and it will
also help you take the necessary steps should problems
arise. Because bluebirds and other songbirds have a very
poorly developed sense of smell and they are not able to
detect human scent, they will not abandon their box if you
open it. Click here to learn more about
monitoring nestboxes.
Category: Monitoring
Problems
Q:
"Everything seemed to be going fine with my
bluebird family, but today I've only seen one bluebird
parent at the box. What should I do?"
A:
If the male bluebird is killed, the female can—as
long as there is plenty of food - take care of the young
herself. Since only the female has a brood patch (a bare
patch of abdominal skin), she is solely responsible for
incubating the eggs and keeping the young warm (called
brooding) during their first week of life. If she is killed
during these two critical stages, the nest is doomed unless
the nestlings can be moved to a foster box or delivered to a
wildlife rehab center. If the nestlings are older than
about seven days, they are sufficiently feathered to stay
warm at night, and the male can (again, as long as there is
adequate food) take care of them.
When you notice that one parent is missing, check the nest
to see what condition the nestlings are in. If they have
succumbed, clean the box out. If they are still alive, make
your decision based on the information, below.
To locate a nearby wildlife rehabilitation expert, go to:
http://www.tc.umn.edu/~devo0028/contact.htm
You might also try contacting your area or regional NABS
affiliate group. You can find a list by state or
province on our Affiliates
page.
Q:
"Something isn't right because I don't see the
parents around and the babies look hungry. What should I
do?"
A: If neither
parent returns after an hour has passed, then check the box
to see if the young are alive. If they are begging
vigorously, they are hungry. If they are listless, they are
in a weakened condition and will likely perish if they are
not immediately warmed up and fed. In either case you should
contact your local wildlife rehabilitation expert as soon as
possible. Not all of the nestlings will necessarily
survive, but the sooner you get them to a licensed wildlife
rehabilitation expert, the better their chances. See
question above for contact information.
Q:
"I checked the nest box and found broken eggs on
the ground outside the box."
A: House Wrens,
which are protected migratory birds, will enter a nest box,
poke small holes in the eggs and sometimes turf some or all
of the eggs out onto the ground. Remove all the pecked eggs
from the box, pick up all eggs and shells from the ground
and dispose of them. If there are intact eggs still
remaining in the box, the female—depending on the stage of
incubation and her temperament—may return. Leave the nest
for a day or two to see what happens. If it is abandoned,
remove the nesting material and move the box to a more
suitable location for bluebirds. House Wrens are less likely
to use a box that is placed at least 200 ft. away from
wooded or brushy areas.
Q:
"I came out to check my babies, and found several
of them dead and strewn out on the ground. Others were still
in the box, but looked like they had been battered on the
head and eyes. HELP!"
A: House
Sparrows, which are exotic pest species, will enter a box
and peck the occupants to death. Clean out the box and
either take steps to either eliminate the sparrows or move
the box to a more suitable location. House Sparrows are
found only around human dwellings, in cities and around farm
buildings. To minimize competition from this aggressive
predator and competitor, place your boxes where sparrows are
not likely to be a problem. Please see our
House Sparrow Control
page for more sparrow management techniques.
Category:
Bluebird Behavior
Q:
"I have a bluebird that has
been relentlessly pecking at our windows for days! We can't
get it to stop. Please help!"
A: During the
nesting season, both male and female bluebirds are extremely
territorial. Typically, the male more aggressively defends
the edges of the territory while the female tends to defend
the area around the nest site. When bluebirds display
territorial behaviors at windows, they are reacting to what
they perceive to be a rival bird. While seldom resulting in
death or injury, this behavior can cause increased stress
levels (for both the birds and the house occupants!) and is
a waste of energy. The behavior generally ceases once egg
laying commences.
The only effective way to deal with this problem is to
eliminate the reflection. Closing the curtains does not
usually work, so other options that might be considered
include: covering the window on the outside with cloth,
newspaper or any other type of paper; hanging garden netting
over the windows; covering the window with hand soap;
placing a window screen over the window; tying several rows
of string across the window (to which are tied several thin
pieces of colorful cloth or ribbon from the string);
hanging long, thin pieces of reflective Mylar over the
window, allowing them to blow in the breeze.
Note: It is important to
remember that bluebirds and all other native birds that use
nest boxes are wild birds that are protected under Migratory
Birds Convention. It is not legal to touch or handle
bluebirds or any other native bird without being in
possession of a banding permit or other special permit.
State DNR offices or provincial Fish and Wildlife offices
should be contacted for more information about permit
requirements.
Getting specific:
Attracting and Keeping Bluebirds
I live in
southern NH. I have six houses in a cluster from 15 to 30
feet apart. The bluebirds come in the morning, sit on the
houses and mess around for a while and then leave. No
takers. Any ideas why they won't stay?
NABS Reply:
If there is
not a football field between your boxes, then they're too
close together. WHY? Because bluebirds are territorial. With
that many houses in close of an area, the bluebirds are
probably using them as perches to look for insects. If this
has been happening on a regular basis, there's a good chance
they are nesting near by. Check to make sure your boxes meet
the requirements for bluebirds and space them further apart.
Please see the NABS fact sheet,
Getting
Started with Bluebirds.
Raising Bluebirds
My mother
has 9-day old Bluebirds. For the first 8 days of their
lives, they were active and appeared healthy. Today, the 9th
day, they are very lethargic and just lay in the nest. She
has checked for parasites and there are none. She lives
south of Dallas. The weather has been very warm until today.
We have had about a 10 to 15 degree weather change due to a
cool front. It is cooler today by maybe 15 degrees. Do you
have any suggestions about what we should do? They have been
very active until today. Now they just lay in the nest and
barely move.
NABS
Reply:
It is quite
possible that something has happened to the parents of your
baby Bluebirds. The first thing you must do is be 100% sure
the nestlings have been abandoned. If possible, watch the
box from a distance for one to two hours to see if they are
being fed. If this is not possible, wedge a very small stick
or weed stem in the entrance hole and return later to see if
the obstruction remains. Nestlings require a great deal of
sleep and that could be one reason they seem lethargic. If
you are POSITIVE the nestlings are abandoned, it is possible
to place them in nests with other nestlings close to the
same age. If this is not possible, call a licensed bird
rehabilitator.
Their problem is not a cold snap but lack of food and water.
It is difficult to revive and raise Bluebird babies. The
female feeds the young every 20 minutes. The babies receive
body fluids via insects. NOT PURE WATER. Do not try to raise
them yourself, but move the babies to different boxes along
your trail with babies of similar ages. Let another bluebird
pair raise the young for you. Make sure the adult birds are
not around before you move them and remember that it is
difficult for the Eastern Bluebird to raise more than six
birds at a time.
The male bluebird will feed the babies if the female is
killed. She won't abandon her babies voluntarily, so
something must have happened to her. The male cannot
incubate the eggs but he will raise the babies by himself
once they have hatched. The male bluebird is very active in
child raising. Also, previous broods have been known to help
a single parent to raise the babies.
The "open-top nesting box"?
I have
heard of another way to discourage house sparrows by cutting
a 3 inch diameter hole in the roof of the blue bird boxes
and putting chicken wire over this. The house sparrows do
not like nesting in the open. Have you ever heard of this
method? Supposedly, it is very new. Vince Baudry and a
company called Native American Nest Boxes also believe these
boxes work well.
NABS
Reply:
Prior to
1979, NABS recommended the open-top box. However, after
receiving a large volume of letters and phone calls from
people across North America telling of how nestlings were
dying in the open-top box from hypothermia caused by wet
nests and cold weather, NABS no longer recommends the box.
NABS' Technical Advisory Committee recently readdressed the
open-top box and voted to not recommend the box. The
Bluebird Restoration Association of Wisconsin (BRAW) which
once recommended the open-top box, no longer does so.
Through their data analysis study, BRAW has determined that
bluebirds do not prefer this style of box. A nest should
never be allowed to get wet. A properly ventilated box with
an adequate roof overhang will prevent this. Bluebirds can
tolerate the cold weather very well, but once a nest gets
wet during a period of cool, damp weather, the chances of
losing nestlings to hypothermia greatly increases.
Is there a way to make supporting NABS part of my
everyday routine?
NABS Reply:
Yes! We
count on the continued support of members like you to make
all that we accomplish at NABS possible. Yet, we know that
there are only so many hours of time you can give and only
so many donations. Now there's a way you can help the
bluebirds while doing your everyday online shopping. When
you access any one of the hundreds of brand name online
retailers through our new online catalog, a portion of
everything you spend comes back to us. Best of all, it
doesn't cost you - or NABS - anything! Click on the button
below and visit our storefront now (major credit cards
accepted!).
Please read
a good book on bluebirds such as THE BLUEBIRD MONITOR'S
GUIDE BY Jack Griggs, Keith Kridler, Cynthia Berger; THE
BLUEBIRD BOOK by Don and Lillian Stokes; or BLUEBIRD TRAILS
by Dorene Scriven, all available from our Bluebirder's
Catalog. Also please consider joining one of North America's
most successful conservation organizations and help NABS
protect our bluebirds.
Note:
The above replies are of the opinion of the North American
Bluebird Society. These replies should be used to help in
your understanding of bluebirding issues. Further research
is often needed, and frequently underwritten by NABS. NABS
welcomes differing points of view which can be submitted in
writing to: NABS, PO Box 43, Miamiville, OH 45147.
