begins the quest of starting a Purple Martin colony quickly learns
that two major problems almost immediately surface. One is the
European Starling. The other is the English House Sparrow.
By now, anybody
that has taken the time to educate themselves about purple martins
and wants to start a colony knows about the wealthy
New Yorker named Eugene Schieffelin, who in the late 1800's,
imported and then turned loose all the birds that were in the
Shakespearian plays. Well, needless to say, it wasn't the
smartest of things to do, but back then, we weren't so aware of the
'politically correct' things to do. Out of all the birds that he
brought over, the only two species to survive were the European
Starling and the English House Sparrow. Both of these are
cavity nesting species and have literally taken over every possible
natural opening where our own native wild cavity nesting birds would
normally nest. And of course, when we humans put up housing
for purple martins, they immediately usurp the house and a nesting
cavity and of course, defend it with their lives.
is now an all out war between the purple martin landlord and the
seemingly never ending hoards of these pests that continually
come. As a good many know, the S&S is a popular trap,
however, being on the larger side, it has troubles actuating quick
enough to capture the sparrows.
with this in mind, I decided to do a little investigating on the
trap and see what I could do to make it just a little
first thing I decided to do was downsize it to specifically fit the
sparrow. If the larger one was too slow, what could be done to
make the mechanism a little faster so we could catch some of the
sparrows that are plaguing everyone. What I've done is make
the trap 'specific'. In other words, I made it to trap
sparrows and not starlings. I made the access hole 1 1/2" in
diameter and that means all the birds that normally look for holes
of that size will fit in it, including the sparrow. However, I
wanted to do one more thing with it. I wanted to be able to
place it directly in the middle of a martin colony without the worry
of catching a martin. The 1 1/2" hole should accomplishes
this. Most of the time, when the martins get back in numbers,
the rest of the birds will leave. But the sparrow is a very
tenacious bird and will take up residence right in the middle of a
martin colony without fear. Sparrows are actually a member of
the Weaver Finch family and because of the way they build their
nests, (filling the compartments with materials to overflowing), the
martins won't even enter the compartments, therefore; they get away
with it and are not bothered by the martins. However, they in
turn won't show the same respect for the martins. They'll
vindictively go from compartment to compartment, pinning (pecking
holes in) the eggs and even killing the young. This is one of
the reasons these birds have to be trapped and destroyed.
within the following page, I'll try to show and describe what can be
done to make a smaller version of the S&S trap, make it
specifically for the sparrows and then put it right in the middle of
your colony. Now, that's not saying that it has to go there,
but that's just one of the options. It can just as easily be
hung under the eaves of a building or on a stand alone pole or where
ever you want to put it.
sheet of 1/2" exterior plywood or one 10 foot long Western Cedar
dozen 1 5/8" long treated bugle head decking screws
gallon Mayo or Miracle Whip jug.
small 1 1/2" hinges
very small diameter nails. I used small finish nails
small piece of .040" thick aluminum
very small washers
#6 x 1/2" long sheet metal screws
sq ft of 1" x 1/2" welded wire screen
dozen short roofing nails
stick (piece) of 4" diameter thin wall PVC tubing
can of black spray paint (If you want the tubing to be
empty 35 mm film canister w/cover
small box of BB's
1 1/4" long 1/4-20 bolt, 2 flat washers and a wing nut
2" long piece of 1/4" all thread, another flat washer and wing
feet of small diameter flexible wire. (small electric fence
wire works good).
- drill motor
with a good selection of drill bits
- a 1 1/2" hole
- jigsaw with
wood cutting blade
pair of tin snips to cut the aluminum
pair of wire cutting pliers
- pair of good
needle nose pliers
drivers (I use a Phillips drive inserted in my drill.
Much easier and faster).
Before we begin
making your trap, we need to assume a couple of things.
One, that the
maker has basic wood working tools and knows how to use them.
Two, that the
maker understands a little about working with wood.
Three, that by
looking at a picture, the viewer understands what is being said or
And four, the
maker can follow written instructions.
So, with that
said, let's build a sparrow trap.
First, you need
to find the material you want to make it from. 1/2" thick
exterior plywood will work good (If plywood is used,
predrilled holes must be used in any edge screwing). I like to
use Western Cedar because it's readily available to me, it's light,
very easy to work with and it will last a long time out in the
elements. White pine will also work if treated and then
The first thing
to do is make the trap frame. The outside dimensions
are 18" long, 10" high and 5 1/2" wide. If you get 11" wide
cedar, this can be made by cutting the board right down the
middle. (The 5 1/2" is plenty for sparrows). I added a
couple of "foot" boards, one under each end because later in the
design, a wing nut will be under the assembly and these feet will
let it set flat on the table.
frame should look like the one above...
Next, let's cut
the jug. Since your trap body is only 5 1/2" wide, the jug
required to fit in this trap has to be as close to between 5 1/8"
and 5 1/4" long as you can get it. I used my table saw
to cut mine, but you can use a good sharp pair of scissors or even a
Dremel tool with a cutting blade on it.. Mark it very
accurately first and then follow the lines closely.
everybody has table saws, so here's a simple way of marking a round
Stack a couple
pieces of wood on a flat surface to form the desired height you
want. Now, lay a 'Sharpie' pen on its side on this stack of
boards and with the jug standing up, slide the jug up to the
pen. Now, as you turn the jug, this leaves you with a nice
level line on your jug. Repeat for the second line at 5 1/4".
build the counterbalance mechanism.
The secret to
quick actuation is the lightness of the materials used to
make the counter balance. The board required is 12" long, 1
1/4" wide and approx 1/2" thick. If you don't have the ability
to plane lumber, then a 3/4" thick piece will work, however, this
piece of wood has to be very light. White pine will
work, but plywood is not a good material to use here. On one
end and along the centerline of the board, pre-drill 2, 1/16"
diameter holes, 1 inch apart. These will be used to mount your
jug. On the other end, pre-drill 1 more hole to hold your
counter balance weight. (Film canister).
At the center
point of your jug, mark and drill two clearance holes, 1/8" in
diameter and 1" apart. Using 2 #6 x 1/2" Phillips head
machine screws, carefully screw the jug in place as
Now in the
center of the bottom of your film canister, drill another
1/8" clearance hole and using a #6 screw, screw it in place as
Now, 4 inches
from the "weighted" end, drive two small nails into the side
of the board at the 4" mark as shown. Leave them sticking out
about 1/4". If you use nails that have heads on them, snip
them off with a pair of wire dykes. I used very small finish
nails, they have very small heads and work very good. Make
sure they are directly opposite each other, forming a straight line
To make the
pivot bracket, first cut a piece of aluminum, 2" wide x 6"
long. It has to be bent to the shape as shown above. The
distance between the two side arms is 1 3/8" if you cut a
piece of wood 1 3/8" wide, the aluminum can be folded down over it
giving you the required inside dimension. This piece doesn't
have to be super strong. It's the vertical sides that create
the strength in the piece and for this purpose, it will do just
fine. Next, mark and drill 2 holes just barely larger than the
nails, 1 1/2" up from the bottom and in the center of each bracket
arm. Then using your tin snips, cut the alum to the approx
shape as shown above. File or sand away any burrs and sharp
Finally drill a
5/16" diameter hole in the bottom center of the bracket. This
hole will be used to attach the balance mechanism to your trap so do
Next, put two
washers on each of the nails and then slightly spread the bracket
arms and alternately insert each nail into its hole. Make sure
the washers are in place and that the bracket arms are not pushing
inward on these washers. If they are, lightly force them
outwards until they are loose. The washers are only spacers
and should not be tight at all. Now, place the unit in the
frame for your trap. Carefully position it in the frame making
sure it will pivot through the full range of motion required to
operate. (I filled my canister with BB's so that it made it
easier to work with). Make sure it sits squarely within the
frame. By moving the bracket around, position the balance so
that the jug is fully within the edges of your frame when
operated. Once you get it located, left to right and front to
back, carefully mark where your bracket hole is on the inside of the
frame. I drew a line at right angles to the mark because I
transferred the mark to the underside of the box so I could drill
it. A small square will work wonders in this situation.
Once marked, use a 3/8" diameter drill and carefully drill the hole
to mount the pivot bracket. Now, add your 1/4-20 bolt and
washer to the bracket, insert it into the trap and then add another
washer and wing nut from the underside to hold in place. After
verifying that you again have full range of operation, everything is
clean and clear of obstruction, tighten the wing nut from
underside. (Now you know why the need for the 'foot boards').
I made a couple
of these traps and in some, I painted the jugs black so that it
would give the illusion of a dark interior. I know sparrows
don't care about shiny surfaces, but just in case, I left a few that
were unpainted and shiny just to see if it did matter.
Now, let's add
the front door.
First cut the
door from one piece of wood, big enough to cover the entire front of
the frame. (Should be 18" x 10"). Before drilling any
holes in the front door, measure down from the top of the frame to
the very top of the opening of the jug. This will be the same
dimension for the top of your hole in your front door.
Now add another 3/4" to get the center of your 1 1/2"
Mine measured 1 1/2" + 3/4" = 2 1/4" from the top of the door down
to the center of my 1 1/2" hole.
horizontally from the end of the box to the center of the jug so
that you have both dimensions to locate the hole. Now you
can drill your 1 1/2" hole in your front door.
Once the hole
is drilled, you'll need to add the hinges...
I used some small 1 1/2"
utility hinges from Wal-Mart and mounted them as shown below.
Adding the latch...
I made a very
simple latch to get into the trap. What I did was cut a small
slot in the end of the door with my jigsaw. I then closed the
door and marked the center of the slot on my frame edge. I
then drilled a hole just a little smaller than the outside diameter
of my piece of all thread. I then stuck it into my drill and
literally screwed it into the hole using my drill. I then
released it from the drill, closed the door and then added the
washer and wing nut.
This makes for
an easy way of opening and closing the front door.
Now if you
like, you can add the front porch so that the sparrows have
something to sit on. And with that done, the front of your
trap should look like the above.
Now for the
by cutting a one piece board for the back panel. (18" x
10"). Then, by pressing down on the jug, measure up from the
bottom of frame. The resulting dimension is the bottom
of the hole in the back panel. Add the required 3/4" to the
center and drill the hole.
Mine measured 1 1/4" + 3/4" = 2" from the bottom of the back panel
to the center of the hole. After drilling the 1 1/2" hole,
attach to the back of the frame with screws as shown.
The Down Chute:
Next, you have
to make a down chute for the sparrow to escape the trap and be
funneled down to the catch cage... This is done as shown
above. The tubing I used is 4" thin walled PVC tubing.
(It can be purchased just about anywhere). The outside
dimensions to this tube are 4 1/4", therefore, you need to make a
frame that has a 4 1/4" inside dimension. The actual
dimensions for the boards used here are (1) @ 4 1/4", (2) @ 5" and
the long one is 8" long. I made mine all 3" wide. Drill
pilot holes and then assemble as shown.
purchase your tubing, take note that one end is larger than the
other. That is the top of the tube. From the
bottom of the tube, cut off a short 10" piece of the
tubing. Now, pre-drill some pilot holes and screw it into the
wood as shown (freshly cut end up).. Now, test fit to
make sure the top of the tube will fit over the short piece in the
Now, you need
to cut your 1 1/2" hole in the back of the assembly. Using
your hole saw, carefully cut the hole making sure it goes through
the tube. Be careful that you don't hit any screws when
drilling the hole.
Next, cut a
piece of 1/2" x 1" cage material and add it on the top of the
assembly as shown. I used short roofing nails to hold it in
place. 1/4" wire cloth will work just as well...
Now, add the
finished assembly to your trap by screwing it in place with two
At this point,
your main trap body is complete. Set the entire unit on the
edge of a table with the down chute hanging over the edge, open the
door and double check your balance mechanism inside and make sure it
is still operating properly. You don't want to accidentally
drive a screw too far through the back and hit any part of the
balance mechanism or it won't work properly.
Now, what you
need to do is fine tune your trap. This is done by adding or
subtracting BB's from your film canister. I used fishing
sinkers to start out with because lead is heavier and will take up
less room. Then, when I got close to the required weight, I
used BB's to fine tune it. Make sure everything is level when
fine tuning the "trip" of the jug. When done, as little as a
quarter and usually about a quarter and a nickel should trip the
trap. It should then slowly return to the top when they are
removed. When this is accomplished, put the top on the film
canister and the fine tuning is complete.
are the numbers you need to work with. They are translated
into pocket change so that the average person can use them to tune
their trap... Although this trap wasn't designed for starlings, the
numbers are here just in case you want to make a larger version and
use it for them. The starling version is 9" wide, has a jug
that is 8 1/2" long and has 2" holes instead of 1 1/2".
put the starling version within your martin colony or anywhere near
where martins will go. It will catch your martins and you do
not want to do that...
The weights are
not exact but are within 2 grams. This should provide you with a
pretty good method of testing your trap.
All of these are
nickel = 5.1 grams
penny = 2.7 grams
dime = 2.3
weights were taken from actual weighed Starlings and Sparrows:
sparrow = 1.1 ounces or 30 grams
starling 1 = 3.0 ounces or
starling 2 = 3.1 ounces or 90 grams
starling 3 = 3.2
ounces or 92 grams
For example, 5 quarters and 2 dimes would
be the approximate weight of a male sparrow.
quarters and 2 pennies would be the approximate weight of a
want your trap to 'trip' as quickly as possible so work to get it to
trip with as few coins as possible. But if it trips with
numbers less than the above, it should work just fine...
Now, you need
to add an attachment board. This is the method used to hang
your trap to where ever you plan to put it. I simply stuck a
board on the back of mine at the centerline of the trap so that I
could screw it in place when I hang it. You can make this
board, (size and shape), to fit your own needs. I made mine so
that I could put the trap on a 4 x 4 post or on the corner of a
building or where ever I wanted to put it.
If you plan to
paint your trap, a good coating of Latex Primer and then a couple
good coats of good White Exterior Latex will make things really look
good and will help make it last a lot longer. I make the down
spout black so that it is less conspicuous.
Now, lets make
a down spout. This is the part of the trap that will deliver
the trapped birds to the cage near the ground where you can get at
On the bottom
of your tube, (where you cut the 10" piece from), is where we're
going to attach the cage. The flared end of the tube has to be
up so that it can be slid over the piece in the down chute.
First, you have
to measure the circumference of your tube. If you have a
normal tube, it should measure about 13 1/2".
about 4, 3/16" diameter holes equally spaced about around the tube
and about 1" up from the end.
Now, cut a
piece of wire cage 12" high and 14" wide. Leave the ends of
the wires on one side. The ends on the bottom are not required
and can be sniped off clean to the bottom cross wire.
Roll the cage
until the ends almost meet.
Using a pair of
needle nose pliers, curl the ends of the wire around the first
vertical wire so that the cage is now closed.
Now, using some
small screws and some large fender washers, attach the cage to your
tube as shown above.
inside diameter of your screen and then cut a round piece of wood to
match. Place it inside the cage and then using at least 3
screws and washers, screw the bottom in place.
Using your wire
dykes, cut out a piece of the cage large enough for you to easily
get your hand inside the cage. Cut as close as you can so
there isn't any long sharp edges to catch a hand on. I used my
Dremel tool to grind them off. A small metal file will do the
Now cut a door
that is 1" taller and 2 full sections wider than the door you cut
out. Leave the 2 end wires on the left side and remove all the
others. Remove all the right wires except the middle one on
the right side. On the left side of the door, bend the two end
wires around the left side vertical of the door to form a hinge.
Now, form the
single wire on the right side of the door to form a small hook so
that it hooks under the right vertical wire of the door. Now,
form the door so that it has some spring to it. That way, the
springiness of the door will keep it latched. When you want
in, all you have to do is squeeze the door and open it.
done, you should have a cage at the bottom of your tube that looks
like the one shown above. Now, what you have to do is practice
opening it with one hand and reaching in with the other while not
allowing your hard caught prey to escape... a trick in itself.
Use a small
metal file and clean off all the little ends of wire that are left
from cutting with the wire dykes. It'll save a lot of
scratches to your own hands and arms.
Now all you
have to do is place your trap where you want to put it. Put it
high enough so that when you slide your down spout onto the down
chute, that the catch basket is about hip high. Makes it
easier to work with. What I did was drive a sturdy nail into
my post and then, once I raised the tube in place, I "hung" the back
of the basket on this nail. It makes for easy removal if
And that's all
there is to it. This trap can be placed right in the middle of
your colony if that's where the sparrows are or anywhere you would
like to put it. They like corners of out buildings a
lot. They seem to look for little nooks and crannies or little
holes that they can nest in. Just BEWARE.
Bluebirds and other small cavity nesting birds will also be looking
for the same thing, so make sure you monitor your trap very closely
and let them go when they get caught. Usually one or two trips
down the tube will make them look elsewhere.
I suggest very
strongly, that if you catch an unwanted sparrow that it be dealt
Back to Chuck's Purple Martin
This page created and
by Chuck Abare
The Registry of Nature Habitats
Copyright 1999 -
All Rights Reserved