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A Less Expensive Wireless Tree Cavity Viewer
Overview:
What: A system used for research
requiring viewing of nesting bird cavities. A simple, clean system without a lot of components to haul around.
Where: Flagstaff, Arizona
When: August, 2004
How: Designed a unit with easily available components ordered from Internet sites and purchased from local stores.
Why: Commercially available product, the Tree Top Peeper (tm) (link to maunfacurer) did not fit in budget.
Huebner, D. P. and S. R. Hurteau. 2007. An economical wireless cavity-nest viewer. Journal of Field Ornithology. 78(1):1-6. [PDF]
Short video clips of camera in action. What you will see is the
examination of Western Bluebird nests in Ponderosa Pine snags in Northern Arizona. Shortly after the camera enters the
cavity it adjusts to the illumination provided by the IR LEDs. Each clip is about 1mb in size, .wmv format. If you have questions about
the design or construction of the system or how this video was captured contact me.
June 2, 2006 (eggs)
July 28, 2006 1 (nestlings)
July 28, 2006 2 (nestlings)
Note the video quality on the tv used to monitor the nest is sharper and clearer than what
you see in this video. Noise was introduced by file compression.
 
Parts:
| Telescoping pole | Long enough to reach cavities of interest. e.g. Hastings HV-240 40' telescoping fiberglass pole
e.g. Crain CMR 50 50' telescoping pole. | $475 |
| Wireless camera | ST-100A 434 Mhz black and white wireless camera. Small enough to fit in most cavities, transmits to TV cable channel 59
CAUTION! The following link may possibly take you to some of the seedier places on the Internet (spy camera suppliers, etc.) but for all the right reasons.
Google search for ST-100A | $200 |
| Handheld TV | Any battery operated TV that receives this non-standard frequency (434 Mhz is between vhf channel 13 and uhf channel 14) will work.
| ~$110 |
| Lighting | Originally used white LEDs from head worn flashlights (less expensive than buying from local
electronics store). Now using 6 near infrared LED's from local electronics store
(#2760143) and a current limiting resistor. Please note that diodes
(including Light Emitting Diodes) only pass current in one direction. This means it matters which side of the LED is connected to the positive
battery terminal. Also, if multiple LEDs are used connect them in series, anode to cathode (+ to -).
These are very bright LEDs and 1, 2 or 3 of them are probably enough to provide good near infrared illumination.
This great LED web site will help you identify anode vs. cathode and
provides other LED info.
If you use a 9 volt battery and #2760143 LEDs, try these values.
| for 1 LED | 270 Ohm, 1/2 watt resistor |
| for 3 LEDs | 220 Ohm 1/2 watt resistor |
| for 6 LEDs | 68 Ohm, 1/8 watt resistor |
Remember that you will not be able to see if the near
IR LEDs are on by looking at them as they produce light longer in wavelength than we humans (and birds) can see.
You will need to point them at the camera and look at your tv to see if they are on. Previewing with a digital still cameras
in a dark room may also permit you to tell if IR LEDs are on (shift the IR light to our visible range).
If you use LEDs other than #2760143 you will need to calculate for its characteristics. Here is one of many on-line LED calculators.
| $14 |
| Camera boom | Protects camera and holds it to telescoping pole. The end of a 24" x 1/4" rod was hammered flat to form a shelf. This proved to be a simple and strong method - recommended. | shop scraps |
| Clamp | Small pieces of 1/4" thick flat aluminum stock to make boom clamp/pole fastener from. Thumb screw to fit thread on telescoping pole attachment point. | shop scraps |
| Heat shrink tubing | Various sizes. Holds camera to boom, protects wires, and gives that "tactical black" look | $15 |
| Miscl. | (2) 9 volt battery clips, 9 volt batteries, wire, solder etc. | $10 |
| Grand Total | Note: the majority of this cost is the telescoping pole | ~$850 |
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