Changing...
Round Holes In Gourds
To
Starling Resistant Entrance Holes
In the last few years
there has been a major drive to find some way of eliminating
European Starlings from Purple Martin nesting sites. Both
martins and starlings are cavity nesting species and fiercely
compete for nesting sites. The starling is around most of the
year and begins nesting much earlier than the migratory martin,
thus, when the martins return, the starlings have all the natural
cavities taken up. However, we as humans supply housing for
martins and therefore, they have a place to nest. Starlings
that still don't have a nesting site are also looking for a place to
nest and often will force their way into a martin site and literally
take over a cavity regardless if a martin is interested in it or
not. Because of their aggressive nature, they will simply take
any compartment they want and once established, are just about
impossible to remove. Often they will evict the martins and
then simply take over the cavity. Starlings then start
building their nest right over the original martin nest, even if
there are eggs or young. Sometimes, they will kill the young
and then toss them out and other times, they will build their nests
right over them as if they weren't even there.
Many uninformed
landlords have the belief that martins and starlings will get along
just fine living in the same proximity of each other in the same
house. This belief is very wrong and starlings should not be
allowed to nest in martin housing. Martins are no match in a
one on one encounter with starlings, especially within the confines
of a cavity such as a martin house and the starling will win every
time. Such encounters often result in the death of the
martin.
Starlings nesting in
a martin site will travel from compartment to compartment,
maliciously breaking the eggs and killing the young of martins while
the martins are away from the nest feeding. They do this to
cut down on competition for nesting space between themselves and
martins.
Also, if a starling
is the first to begin nesting in a martin house, then they will
drive any martins away that try to nest in the same house, thus
resulting in no martins coming to your housing.
However, recently a
man by the name of Charles McEwen from Moncton, New Brunswick,
Canada, made a discovery that has made a large impact on the hobby
of keeping purple martins. It's called the 'Crescent
shaped' Starling Resistant Entrance
Hole. The use of crescent shaped SREH's does a number
of things to protect your martins while they are nesting in your
housing, and for the most part, will end most of the problems having
to do with starlings. In fact, the use of them will prevent
the starling from even entering your martin housing.
Here are a few
examples of why I say that:
-Purple Martins are
able to negotiate crescent shaped SREH's.
-European Starlings
are not and thus can no longer get into your martin housing.
-Not only starlings,
but other possible threats to the martins are also eliminated.
Some of these are:
-The friendly little squirrels that just happen to like freshly laid
eggs.
-Blue Jays
-Crows and Ravens
-Screech Owls
-Barred Owls
-and the Great Horned Owl
Here's how it
works. If you put a hole in your housing that measures exactly
to the dimensions shown above, it will just about solve all your
problems that you've had around your site dealing with the above
list of predators. The dimensions are critical. Anything
under 1 3/16 inches high and the martins can't get in, anything over
and the starlings can. The two dimensions are critical and it
takes a little longer to cut the holes, but if cut accurately to the
dimensions, then it all works. The easiest way I've found to
make them is to carefully make yourself a very accurate template
from a flexible material and then use that to trace the lines onto
your housing. Then, you simply have to cut it out using a jig
saw and then finish it with a wood rasp.
Sound too good to be
true. I thought so too, but this spring, I changed my entire
site over to them and trust me, they work. I am no longer
plagued by starlings. In fact, I can honestly say that since I
made the switch over, not one starling has made it into my
gourds. I have not lost one egg or a single chick to
starlings. In fact, I watched for over 2 weeks while a pair of
starlings tried to get into a gourd and no matter how hard they
tried, they never made it in.
So, you're starting
with a new site and have been told to start with round holes and
then switch over after they have been established. Not
so. New sites are being established every day and they are
starting out with the crescents. I've even helped change over
a number of sites to the SREH's and they too are now starling
free. Therefore I strongly urge anyone that wants to keep
martins, make the change and just watch for yourself. It won't
be long before you realize your martins are safe within their gourds
or houses and you will feel much better about it.
Materials/
tools required and some suggested sources for them:
A good sharp Utility
knife (Wal-Mart, K-mart)
A bunch of #6 x 1/2"
lg Phillips Pan Head self tapping sheet metal screws. (Wal-Mart,
K-mart, 100 to a pack)
"Small" Keyhole saw
or jigsaw
A wood rasp with one
side rounded (Wal-Mart)
A pair of safety
glasses. (A blade could snap and let's just be safe).
A short scale or
ruler that has graduations of 1/16"
A small flat paint
brush (If you use caulking)
DAP caulking with
silicone added. (Brilliant white)
A caulking gun
The following are the
procedures for making and cutting these holes in gourds that already
have round holes in them.
Materials/
tools required and possible source for them:
Some Polystyrene or
Polypropylene (source given below)
A good sharp Utility
knife (Wal-Mart, K-mart)
A bunch of #6 x 1/2"
lg Phillips Pan Head self tapping sheet metal screws. (Wal-Mart,
K-mart, 100 to a pack)
1/16" and 1/8" drill
bits and a drill
"Small" Keyhole saw
or jigsaw with a scroll cutting blade
A small wood rasp
with one side rounded
Flexible straight
edge (I used a 6" piece of the Styrene)
A pair of safety
glasses. (A blade could snap and let's just be safe)
A short scale or
ruler that has graduations of 1/16"
White Latex Caulking,
(Optional)
A small flat paint
brush (If you use caulking)
First, you have to
obtain some material to make the "add-ons" from. The thickness
for these add-ons can be .040" to .060" (approximately
1/16 inch thick) and if possible, the color you want is white, (of
course). I found that the easiest material to use was the
small thin somewhat square plastic household trash cans sold at
Wal-mart and K-mart. They are very 'flexible' and easily cut
with a sharp utility knife. Once you get your trash can,
simply cut out all the flat sections with your knife and you're
ready to begin.
Here's how I did
mine:
First, a pattern of a
crescent shaped SREH "add-on" will have to be made. (Use the
drawing below). I made mine from a piece of the plastic I cut
out of my trash can. Take your time making it. The
outside dimensions don't have to be that accurate, but it will be
the pattern for all your add-ons so you want it to be pretty
good. The hole portion however, has to be pretty
accurate. It also has to be accurate because if it's too big,
the starlings can get in and if it's too small, the martins
can't.
You should end up
with a piece that looks like this.
Next, I laid the
pattern on my plastic, traced it with a thin marker and simply cut
it out by following the lines using the ‘utility’ knife. I then
drilled the 1/8" holes to screw it onto my gourds. (One in each of
the 4 corners approx as shown).
Now,
gourd prep.
Take a gourd that has
a round hole in it. Lay your flexible straight edge even with
the bottom of the hole so that it will be parallel with the ground
when it's hanging. Using a ‘sharp’ pencil, draw a
horizontal line, even with the bottom of the round hole. About 3
inches either side of the hole will be plenty long enough.
Now, lay your freshly
cut out ‘add-on’ over the hole with the bottom of the piece setting
on the line and trace the inside curvature of the crescent on the
gourd. Only part of it will actually be on the gourd, the rest
is hole. Using a jig saw or even a small keyhole saw, start at
the hole and work your way out in both directions being very careful
to keep the line very straight. Next, remove the part of the
gourd that you drew the line around.
Now, lay your SREH on
the gourd with the bottom setting exactly on the horizontal line you
cut and centered over the hole. Pre-drill a 1/16" hole in the gourd
where the lower left screw hole is in the pattern. Add a 6-32
x ½” long Phillips self threading screw. Now that one screw is
in place, you can maneuver the piece around more easily. Level the
other side of the piece to the horizontal cut. Now, use the
scale and check your measurement. It has to be 1 3/16" and is
easy to achieve by just twisting the add-on. Now holding the
piece in place, pre-drill and add the right screw. Complete
the assembly by pre-drilling and adding the two top
screws. Double check your opening dimension, it's
important. Now if necessary, using your knife or round edge of
your rasp, clean up the edges of the gourd near the half moon so
that the crescent is accurate. If you need to do a little fine
tuning, use your wood rasp and file away the required material.
I like the clean
look, so I added some DAP Kwik Seal (white… 15 year... in the red
tube… no added silicone… dries faster… Wal-Mart brand), and made the
front of the gourd look like there wasn't even an add-on
there. Apply the caulking and then with a small paint brush,
smooth it out to make it look good. I even put a little under
the hole for their feet to grab onto. I just think it gives a
better finished look. Then, let it dry over night.
What you end up with
is the following. A good looking gourd that is starling
resistant and just waiting to be filled with baby martins.
The reason I left the
bottom of the add-on piece open was I wanted the martins to have
natural gourd surface for their feet to land and cling to.
Just my own little quirk, but I feel they like the feel of natural
better. It also makes it easier to add it to a spherical
surface.
Now, one last thing,
if you don’t want to spend the time making them from plastic, Frank
Prekup http://www.atlanticbreezes.com/pprekup.htm
has a die that punches these crescent shaped SREH’s out of thin
aluminum and they are ‘very accurate’ and I’m sure he could be
persuaded to make these for you, and yes, it would work just as well
as the plastic and the caulking would fill all around it and make it
look just like my plastic versions. You would just have to make sure
all the sharp edges were well covered with caulk so neither you nor
your birds would be hurt. A claw could become entangled in a
loose edge. I don’t know what Franks prices would be, but I’m
sure he would come up with something fair.
OH, and one last
thing. This will also work for any type of housing you want to
change. Wooden houses and plastic gourds alike.
Plastic
Gourds
As of late, some plastic gourds have made their
introduction to the martin markets. Both of these can and should be
worked to include the crescent SREH's.
The above
gourd is made by Natureline. Although they don't yet have the
crescent blanks, you can get a solid blank and then cut the crescent
into it yourself. It really isn't that hard. Most of the material
can be drilled away using a 3/8" drill and then use a utility knife
to trim away the rest to form the crescent.
Likewise,
the SuperGourd with round holes and sold by the PMCA can be changed
using the same technique as shown above. The add-on should be
rounded on top to fit the curvature of the SuperGourd canopy. It
works exactly the same and the birds hardly even notice. However,
the caulking doesn't stick to the plastics very well, but if the job
is done neatly enough, it really isn't needed.
These
Crescent SREH's are something I feel are very important. Starlings
have become a very big problem in some places and of course, the
average landlord can't sit around all day keeping watch on his
colony. With the employment of these SREH's, 99.9% of your starling
problems are no longer existent, and I personally enjoy sitting back
and watching my martins go in and out of their gourds, free from
harassment from starlings.
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Woodside Gardens
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