3. Build PVC nest container

Step 1. Cut lengths of PVC

Materials

• Respirator that covers your face and mouth
• Vice and workbench
• Work gloves
• Ear muffs or plugs
• Multi-tool with semi-circular bit
• Metal hose clamp that fits around 3in diameter PVC
• 3in diameter PVC (Schedule 40)
• Flexible measuring tape
• Pencil
• Large flathead screwdriver

Methods

1.1. Protect yourself with the respirator, work gloves, and ear muffs

1.2. Place the PVC in the vice attached to the work bench

1.3. Use the measuring tape to mark a ~14 cm length of PVC

1.4. Place the hose clamp at this mark and tighten with the screwdriver. Make sure the hose clamp sits evenly around the PVC

1.5. Mark a circle around the PVC with the pencil using the edge of the hose clamp as a guide. Then remove the clamp

1.6. Use the multi-tool to cut the PVC along this line. Shift the PVC in the vice to make 3-4 separate cuts

Step 2. Drill entrance holes for nest containers

Materials

• Full-face respirator, work gloves, ear muffs
• Vice and workbench
• ~14 cm lengths of 3in diameter PVC
• Cordless drill
• 2 1/8in diameter hole saw and chuck (Milwaukee)
• Flathead screwdriver
• Pencil
• Flexible measuring tape

Methods

2.1. Protect yourself with the respirator, work gloves, and ear muffs

2.2. Secure the length of PVC horizontally in the vice, with one end sticking out

2.3. Use the measuring tape and pencil to mark a horizontal line 5.5cm from the bottom of the end of the PVC that sticks out

2.4. Secure the hole saw in the chuck and then in the drill

2.5. Place the bottom of the hole saw just above the marked line

2.6. Drill the hole while placing even pressure on the hole saw from above. You may need to stand on a short stool for more leverage. If the hole saw sticks, then reverse the drill and gently drill forwards again until the drill eats smoothly through the PVC

2.7. Use the screwdriver to push the circular piece of PVC out of the hole saw

Step 3. Place beam breaker mounts on nest containers

Materials

• Full-face respirator, work gloves, ear muffs
• Vice and workbench
• One pair of 3D-printed beam breaker mounts
  • Each mount holds 1 of a pair of beam breakers. Across the 2 mounts, the outer beam breakers will be the first a bird encounters while entering the nest container (before the RFID antenna). The inner beam breakers will be the second (these sit outside of the nest container but after the RFID antenna)
• ~14 cm lengths of 3in diameter PVC with a circular entrance hole
• Cordless drill
• 9/64 in and 7/32 in drill bits
• Hot glue gun
• Dremel with a thin cylindrical and tapered bit for grinding/smoothing
• Thin file
• Pencil
• Flexible measuring tape

Methods

3.1. Protect yourself with the respirator, work gloves, and ear muffs

3.2. Secure the piece of PVC in the vice horizontally with the hole facing upwards and the bottom sticking out

3.3. Use the pencil and measuring tape to mark a horizontal line 7cm from the bottom of the PVC, immediately adjacent to the entrance hole

3.4. Use the measuring tape to extend this line across the entrance hole, up to ~ 1cm on either side of the hole

3.5. Use the measuring tape again to mark a vertical line 0.5 cm from the edge of the entrance hole on either side. These lines should now mark the corners where the 3D-printed beam breaker mounts will sit (e.g. line up the corners)

3.6. Drill through the top holes (2 total, 1 hole for a screw per beam breaker) of each beam breaker mount with the 9/64 in bit

3.7. Place a dab of hot glue on the back side of each mount, while making sure that the hot glue doesn’t cover the holes for the inner beam breaker. Any hot glue that covers the holes will cause the drill to slip in later steps, and the mounts will need to be reattached. Secure each mount to the nest container while lining up the corners with the corner marks made in the previous step

3.8. Apply pressure to each mount for about 20 - 30 seconds while the hot glue dries. As you do so, check that the bottom holes for the outer beam breaker pair line up well with each other

3.9. Once the hot glue is dry, use the holes in the mounts as guides for drilling through the PVC at the right angle to attach the beam breakers with screws, and also to open up a hole for the inner beam at the right angle. The receiver and emitter need to be able to communicate smoothly, and it’s very difficult to drill a hole for each LED at the right angle without a guide. Rotate the PVC in the vice so the area you want to drill faces straight up. Drill through the top holes of each mount with the 9/64 in bit. These holes are for attaching each beam breaker with screws. Then drill through the bottom hole for the inner beam breaker only with the 7/32 in bit. Make sure the drill passes through the PVC.

Making the LED holes for the inner beam breaker pairs increases the likelihood that the receiver will pick up the beam from the emitter. This could be done for the outer beam breaker pair too, but I haven’t found that to be necessary.

If a mount pops off of the container while drilling at this step, then rip off the old hot glue (e.g. with a flathead screwdriver) and reattach with hot glue again as in steps 3.7 and 3.8. If a mount pops off after you drilled a hole, then just make sure that the holes in the mount and the PVC line up as you’re gluing the mount back on. You can stick the thin file or a pencil through the hole while gluing just to be sure

3.10. Countersink the holes for all 4 screws on the inside of the nest container (e.g. right next to the entrance hole and inside the PVC after the entrance). These are the screws that birds will see as they move into the nest container, and any screw heads sticking out could be a source of neophobia for some birds. Use the Dremel with the thin tapered bit to countersink these holes

3.11. Use the thin file to clean the edges of the mount holes and the new holes in the PVC. Remove burrs and threads of PVC, especially for the LED holes

Step 4. Drill holes for airflow

Materials

• Full-face respirator, work gloves, ear muffs
• Vice and workbench
• ~14 cm length of 3in diameter PVC with a circular entrance hole, beam breaker mounts, and a back door
• 3 in diameter PVC cap
• Multi-tool with semi-circular bit
• Hammer
• Cordless drill
• 5/64 in bit and/or 3/32 in drill bit
• Dremel with a cylindrical bit for grinding/smoothing
• Pencil
• Flexible measuring tape
• Eraser
• Black Sharpie

Methods

4.1. Protect yourself with the respirator, work gloves, and ear muffs

4.2. Place the nest container in the vice with the entrance hole facing straight up

4.5. Move the PVC piece around in the vice to mark and drill holes for airflow. Note that these airflow holes do not have to be perfectly measured, but these measurements are a guideline to ensuring that similar containers can be used across experimental replicates:

For less airflow holes

• Mark 2 columns 1 cm and 3 cm from the right edge of the door without hinges. Then mark rows 2 to 10 cm every 2cm from the top of the nest container

• Repeat for the left hinged edge of the back door, but skip the hole 3 cm across / 6 cm down or other holes if they interfere with the beam breaker mount

• Mark a horizontal line above the entrance hole, 2 cm from the top of the container, that connects the two 3 cm column lines at the very top of each. Along this line, mark columns from 1 to 10 cm every 1 cm

• Drill these holes for airflow using the 5/64 in bit (Drill on all “+” marks)

• Place the PVC cap in the vice with the bottom facing up. Mark 2 circles of holes for airflow:

  • Mark 4 holes in each cardinal direction about 2 cm in from the outer edge. Then mark additional holes evenly spaced between these for 12 holes total

  • Mark 4 holes in each cardinal direction about 4 cm in from the outer edge. Then mark additional holes evenly spaced between these for 8 holes total

  • Mark 1 hole in the very center

• Drill these holes for airflow in the cap, which is where the birds should nest, using the 3/32 in bit

For more airflow holes

• Start marking holes before drilling, and with the nest container body separate from the cap

• Mark holes to the right side of the door (no hinges) up to just before the adjacent beam breaker mount:

  • 3 columns of holes that are 4 cm from the top of the container, and 1 cm right from the edge of the door, 1 cm between columns. 6 rows of holes per column, and 1 cm between rows per column

• Mark holes to the left side of the door (with hinges) up to just before the adjacent beam breaker mount:

  • 1 column of holes 4 cm from the top of the container and 1.5 cm left of the edge of the door. 4 rows of holes 2 cm apart

• Mark holes within the bounds of the door

  • 9 columns of holes from 0.5 cm from the top edge of the door to ~1 cm from the bottom edge of the door. Columns should be 1 cm apart, and rows will be about 1 cm apart within a column. This turns out to 8 rows of holes per column

• Mark holes around the lower part of the container and around the sides of the cap

  • Here you should place the cap firmly onto the bottom of the nest container. You can set the nest container upside down and gently tap the bottom of the cap with a hammer to make sure that the cap sits firmly and evenly on the container itself. There should be ~ 1.5 cm of free space between the bottom of the door on the nest container and the lip of the PVC cap

  • Use the Sharpie to draw a vertical line from the right bottom corner of the door down to about 1cm onto the PVC cap itself. Draw a horizontal line right where the cap meets the container, from a few cm left of and just under the bottom right corner of the door. These lines should make a T shape

  • Use the multi-tool with the semi-circular bit to score each of these lines into the nest container and cap. Scoring these lines is important to ensure that you can line up the container and cap later after these parts are disassembled for cleaning. Without these markers, it can be very hard to later line up holes for airflow that will be drilled through 2 layers of PVC (through the side of the cap and the nest container)

  • Mark two rows of holes on the bottom area of the nest container starting 0.5 cm below the bottom of the door. Rows should be 0.5 cm apart, and make holes per row 1 cm apart all around the nest container

  • Mark 6 rows of holes all around the side of the PVC cap (these will be the holes drilled through 2 layers of PVC). The first row should start at the very top edge of the cap itself. Make the holes 1 cm apart per row, and continue marking holes in columns all around the cap, with columns spaced 1 cm apart

• Mark holes on the bottom of the PVC cap. Start with 1 hole in the very center, then 4 evenly spaced holes around this center hole. For each of these 4 holes, mark a matching hole at the very edge of the bottom of the cap, and connect these with a line of 5 evenly spaced holes. Then fill in the gaps between these lines of holes such that there are concentric circles spaced ~1 cm apart. Holes within each concentric circle should also be spaced ~1 cm apart

• Drill all holes with the 3/32 in bit

Step 5. Make doors for nest containers

Materials

• Full-face respirator, work gloves, ear muffs
• Vice and workbench
• ~14 cm lengths of 3in diameter PVC with circular entrance holes and beam breaker mounts
• Multi-tool with semi-circular bit
• Cordless drill
• 5/64 in and 3/16 in drill bits
• Small vice grips
• Heavy duty wire cutters
• 3/4 in hinges with 4 screw holes x 2
• 2-28 x 3/8in long Phillips head screws x 8
• M5 12mm long screws x 2
• Thin flexible wire (10 cm long)
• Needle nose pliers
• Dremel with a cylindrical bit for grinding/smoothing
• Pencil
• Flexible cloth measuring tape
• Flexible metal measuring tape
• Small and large Phillips head screwdrivers

Methods

5.1. Protect yourself with the respirator, work gloves, and ear muffs

5.2. Place the PVC in the vice with the entrance hole facing straight down

5.3. Use the pencil and cloth measuring tape to mark a door on the opposite side of the entrance hole:

• 5cm from the bottom of the container
• A 10cm wide, 8cm tall door

5.4. Use the metal measuring tape as a guide to extend these marked lines and outline the straight edges

5.5. Place each hinge about 1cm from the top and bottom of the marked door, while lining up the middle of the hinge with the line marking the left side of the door. Use the pencil to mark where the holes for each screw (4 per hinge, 8 total) should be drilled

5.6. Drill these holes using the 5/6in bit

5.7. Cut out the door along the marked lines with the multi-tool

5.8. Use the Dremel and smoothing bit to smooth all new edges around and on the door itself

5.9. Cut the hinge screws so that they don’t poke into the inside of the nest container. Hold each screw about halfway down from the head with the vice grips and clip off the extra length with the wire cutters

5.10. Use the small screwdriver to attach each hinge with the trimmed screws

5.11. Drill 2 holes with the 3/16 in bit for the M5 screws. These screws will hold thin flexible wire to secure the door:

• Drill one hole on the top right of the door, 1 cm from the top and 1 cm in from the edge of the door
• Drill another hole in the main container in line with the edge of the door and 1cm to the right of the door

5.12. Attach these screws with the large screwdriver, making sure the ends are flush with the inside of the container. Make a loop fastener by twisting the thin wire around these screws with the needle nose pliers:

• Wrap the wire loosely around the head of the M5 screw just above the door, leaving about 1 cm free

• Make a loose loop by twisting the free end around the wire that hangs down below the screw. use the needle nose pliers for twisting and flatten the sharp end

• While holding the loop to have some slack on the wire, twist the opposite end just under the head of the M5 screw in the door. Make sure that the sharp end is up against the head of the screw itself

Step 6. Finishing touches on the nest containers

Materials

• Full-face respirator, work gloves, ear muffs
• Vice and workbench
• ~14 cm length of 3in diameter PVC with a circular entrance hole, beam breaker mounts, and a back door
• 3 in diameter PVC cap
• Square corner brackets (1 3/16 in x 1 3/16 in legs, 4 holes per bracket) and M3 6mm screws x 4
• Philips head screwdriver
• Cordless drill
• 9/64 in, 5/64 in and 3/32 in drill bits
• Dremel with a cylindrical bit for grinding/smoothing
• Pencil
• Flexible measuring tape
• Eraser
• P60 or other rough sandpaper
• P220 or other fine sandpaper
• Sink and soap
• Hammer
• Fine metal punch
• Black Sharpie
• 2 pairs of beam breakers with 4 M3 screws 35mm long, M3 hex nuts, and small flat washers that fit M3 screws
• Local setup of tracking system on a Raspberry Pi connected to a display, mouse, and keyboard

Methods

6.1. Protect yourself with the respirator, work gloves, and ear muffs

6.2. Place the nest container in the vice with the entrance hole facing straight up

6.3. Use the pencil and measuring tape to mark 4 holes about 0.5 cm above and below the entrance hole. These can be used to secure the RFID antenna with cable ties if necessary

• Use the 9/64 in bit to drill these 4 holes

6.4. Mark and drill holes for attaching the temperature probe inside the nest container with a cable tie

• Mark a horizontal line 7 cm from the top of the container next to the right side of the door (no hinges), and mark 2 vertical lines at 1 cm and 2 cm over from this same side of the door

• Drill these holes on the “+” marks with the 9/64 in bit

6.5. Attach two square corner brackets to each container. This is to stabilize the containers in the modified Prevue cages:

• Mark a vertical line 10 mm left of the top left edge of the door (the side with hinges). Line up the right side of one bracket with this line while lining up the top corner with the top edge of the nest container. Use the pencil to mark both holes that should be drilled into the container

• Mark a vertical line 22 mm right of the top right edge of the door (the side without hinges). Line up the left side of one bracket with this line while lining up the top corner with the top edge of the nest container. Use the pencil to mark both holes that should be drilled into the container

• Drill these 4 holes with a 3/32 in drill bit

• Use the Philips head screwdriver and the M3 6mm screws to attach each bracket to the container, with one arm per bracket sticking off the top edge of the container

6.6. Drill holes for the two nest container shields that will be placed over the beam breaker mounts on either side. In order to do this, you need to already have templates of the shields made that work with this nest container design and the mounted beam breakers:

• Use the pencil and flexible measuring tape to make 4 "+" markers where holes should be drilled:

  • Turn the container so the back door faces you. Mark 4.5 cm to the right of the lower right edge of the door

  • 3 cm left of the lower left edge of the door

  • Turn the container around so the front entrance faces you. Mark 5 cm left of the righthand bracket, use the lowermost screw as a visual guide for horizontal placement

  • 3.5 cm right of the lefthand bracket, again using the lowermost screw as a horizontal visual guide

If the distance between the brackets and entrance holes varies across containers (such that the nest shield will partially cover the entrance), then shift the uppermost marks left or right as needed

6.7. Shift the PVC container in the vice again so that the entrance hole faces straight up. Use the Dremel with the sanding bit to sand down an area shaped like an inverted funnel right above the top of the entrance hole. The wide side of the funnel should connect to the entrance hole. This is to create a smooth edge and a sloped area for the the thin wires of the RFID antenna that will sit in the entrance

6.8. Shift the container in the vice to smooth sharp edges and burrs all over the inside and the outside with the Dremel and the sanding bit. Use the thin file to smooth areas that are hard to reach with the Dremel, Make sure to smooth down any sharp edges from the hinge screws poking inside the container with the Dremel

6.9. Use the Dremel and the sanding bit to create a scuffed surface inside the nest container below the entrance. Make horizontal and vertical scuffed lines in this area. This is to create a slightly rough surface so the birds have some grip if they need to climb out (especially fledglings)

6.10. Use the P60 or other rough sandpaper to smooth off sharp edges and burrs inside and outside of the cap

6.11. Place the nest container back in the vice. Use the P220 or other fine sandpaper to sand all printed text on the surface of the container. The container should now be a uniform white color all over, aside from some scuffing marks from wear and tear

6.12. Wash off all of the fine plastic residue with mild soap and water. Let the container dry for a few hours

6.13. Use the flexible measuring tape to mark vertical and horizontal 1 cm lines (forming an L) on the inner side of the door of each nest container (between the 2nd and 3rd air holes on the bottom row). Then use the Sharpie to pass over these pencil lines. These lines will be a guide for videos, such that we can measure distance in videos as needed (with the caveat that the horizontal line was drawn on a curved surface)

6.14. Add a unique identifier to each nest container. Write out "container_XX", with XX being a unique numeric identifier, in Sharpie underneath the door or elsewhere on the back side of the container. Use the metal punch and a hammer to mark out the "XX" numeric identifier for more permanent identification

Step 7. Test beam breaker sensors on the nest container

Materials

• Fully assembled nest container (~14 cm length of 3in diameter PVC with a circular entrance hole, beam breaker mounts, a back door, and the 3 in diameter PVC cap)
• Eraser
• 2 pairs of beam breakers with 4 M3 screws 35mm long, M3 hex nuts, and small flat washers that fit M3 screws
• Local setup of tracking system on a Raspberry Pi connected to a display, mouse, and keyboard

Methods

7.1 Test the beam breaker mounts to make sure the beam breakers communicate well. Attach the 2 pairs of beam breakers to the mounts with the M3 screws and hex nuts. Place 2 flat washers (or 1 if thicker) between the mount and the beam breaker on the hole for the screw, so that each beam breaker is evenly oriented while tightening the hex nuts

7.2. Attach the beam breakers to the jumper cable harnesses (power, ground, data) while the Pi is powered off

7.3. Turn on the display and the Pi, and open 2 terminal windows

7.4. In one window, navigate to the tracking system software:

• cd /home/pi/Desktop/Abissmal

7.5. Run the tracking system in this same terminal window:

• bash Main.sh

7.6. In the second window, print the contents of the log for the current data to monitor sensor output:

• tail -f /home/pi/logs/[name of log file for the given day]

7.7. Then move an object through the nest container entrance to confirm that the resulting beam breaks per each pair of beam breakers appears in the log file

7.8. Turn off the Pi and display and disconnect the beam breakers

7.9. Erase all pencil markings from the surface of the nest container