In some areas of the country, particularly north of the Mason-Dixon Line, landlords can enjoy a reprieve from the vandalous European Starlings. Landlords, in these areas, notice that the starlings nest one time, and after they are either already on nests, or after they have nested, starlings are not as fierce in their search for nest sites in martin houses. Consequently, this is a more restful time for martins from starlings.

If you have half-moon, or crescent-shaped, starling-resistant entrances, you can now make them adjustable. In other words, when the starlings are not aggressively seeking nest cavities in martin houses, you can raise the entrance doors a 1/4"+ higher allowing the busy martin parents easier entrance to their compartments when the demand to feed their young is high and requires many more trips in and out of the compartments.

If starlings do persist, then, you can always set the doors to the original position according to specs:   1 3/16" opening.

MATERIALS

Plastic (1/8" plexiglass, plastic gutter, PVC
Plywood (1/2" outdoor grade)
Pan Head sheetmetal screws (8x3/8")
Wood screws (6 x 3/8")
Primer
White oil-based paint (lasts longer)
Trio-Mfg. house doors

TOOLS

Tin snips
Jigsaw or scroll saw
Drill
2 drill bits (1/8" & 1/2")
Tape measure
Pencil
2 cans (2" diameter and 3" diameter)
Phillips screwdriver

You can download a larger version of this drawing.

Making Adjustable Plate

1. Cut plastic into 2" x 3½" square.

2. Measure 5/8" from bottom of plastic square and make a straight line.

3. (fig 1) Find the center of the above line, place the 3" can at the edge and trace the outside diameter onto the plastic square.

4. Measure a ¼" on both sides and mark 3/8" from the top and 1" apart.

5. (fig 2) Connect the two lines so you have a 1" long line. Make another 1" line 1/8" parallel to t his. You now have your screw slot. Repeat this procedure for the opposite side.

6. Take a 1/8" drill and drill holes from top to bottom of the screw slots.

7. If necessary, use a scroll saw or copping saw to make it a clean and continuous slot.

8. (fig 3) Cut out the semi–circle. You now have a complete adjustable plate.

Making Modified Hole

1. (fig. 4) Cut out a 4" x 4½" piece of ½" plywood.

2. Measure ¼" from the bottom and draw a line across the length. Find the center along this line and darken 3".

3. (fig. 5) At the center of this 3" line, measure 1 3/16" up and mark it. Take the 3" can, center and line it up with the 1 3/16" line. Trace the outside diameter of the can down to the 3" line. You now have the standard starling–resistant entrance.

4. Take the 2" can and center it with the bottom of the 3" line. Trace the outside diameter of the can. You now have an enlarged starling–resistant entrance.

5. (fig. 6) Drill a large hole (½" bit) in the center of this diagram. (as instructed in #4)

6. Use the scroll or copping saw to cut out this diagram by using the drilled hole to insert the blade.

7. (fig. 7) The cut hole should resemble a bell.

8. Seal and paint.

Modifying Trio Doors

1. Take the finished wooden hole, center and trace the bell shape ¼" from the bottom of the aluminum door.

2. (fig. 8) Draw a diagonal line from the middle edge of both sides of the Trio hole. Make it a little bigger than the lines you traced from the previous step. The shape should resemble a large triangle with a rounded top.

3. Cut out this shape with the tin snips, and, file the edges.

Attachment of Wooden Hole to Trio Door

1. Place the wooden door on a flat surface with the front of the Trio door on top.

2. Center the wooden door. Don’t leave any aluminum hanging over the wooden hole. Cut it larger, if necessary.

3. (fig. 9) Once this is done, drive (2) 8" x 3/8" sheet metal screws through the Trio doors into the wooden hole at the two farthest points. Drill small holes, by hand if necessary, or use a power screwdriver.

Attachment of Adjustable Plate

1. Place the plastic adjustable plate over the hole of the modified Trio door.

2. Measure 1¼" from the bottom of the hole to the top center of the semi–circle of the adjustable plate.

3. Use permanent marker and mark the wooden plate with a line jus below the plastic adjuster. This will serve as the 1 ¼" marker for easy measurement when adjusting the door up and down.

4. (fig. 10) Hold adjustable plate at the mark previously made, and place (1) 6" x ½" wood screw in the center of both screw slots. Once again, drill pilot hole, if necessary, and screw by hand. Tighten down the plate just enough to keep the plate from moving.

5. Check the hole openings and make sure it is opening is 1 ¼". This size should deter starlings from entering. You can make the hole smaller by loosening the screws and moving the plate to the bottom of the adjustment mark. To enlarge it, follow the same procedure, just move the plate up. To maintain the 1 ¼" size, lower it to the top of the mark.