SM4 Study Protocol

Have An SM4 Sensor?

Download our settings file here. Deployment criteria are:


  • Wildlife Acoustics SM-4 recorder (provided)
  • 18-gauge or thicker galvanized wire (provided)
  • Four D-sized alkaline batteries (provided)
  • SD card (provided)
  • GPS device or smartphone with GPS and compass capabilities
  • Camera or smartphone
  • Notepad and writing utensil

Sensor Location Criteria:

  1. Greater than 5 km from an airport
  2. Greater than 2 km from a highway (speed limit greater than 50 mph)
  3. Greater than 300 m from any other roads
  4. Greater than 100 m from the habitat edge
  5. Greater than 4 ft from a walking trail
  6. Not located next to a river
  7. Flat terrain preferred


  1. After identifying a suitable location using the criteria above, mount the sensor on the smallest tree available with a DBH between 3” and 3’ and without secondary branches. Trees with smaller diameter trunks are favorable. Upon finding a suitable tree:
    • Make sure the recorder is facing south. The recorder should be installed at eye level.
    • To install the recorder, feed the wire through the eye-holes at the top and bottom of the recorder and wrap the wire half-way around the tree. Where the wires cross, twist them multiple times in order to fasten the sensor. Make sure that the wire is taut so that the recorder will not slip. Any additional wire should be folded up and tucked close to the tree.
  2. Save a GPS point or write down the coordinates
  3. Take photos of the recorder on the tree and of the surrounding habitat
  4. Write down a brief description of the location (Are there trees, shrubs, grasses, other plants? How dense is the vegetation?) and what you hear (Are there people talking, road noise, aircraft, running water?)
  5. Turn on the recorder no later than 11:59 pm on Thursday, August 17
    • Open the recorder cover using the latch on the right hand side
    • Move the power switch (“A” on figure below) on the upper right-hand side from “EXT” to “INT”
    • Wait for unit to turn on.
    • Press the “Start Schedule” button (“B”)
      1. The screen will have a message that says “WARNING! Delaying until 2017-August-18 00:00:00”
      2. After this message, the screen will go blank. This means everything went well!
      3. If you do not see this message, or if you have any questions regarding the deployment, please immediately call somebody at the Center for Global Soundscapes using the phone numbers listed at the bottom of this protocol sheet.
    • Close the cover of the recorder
  6. Remove the recorder from the tree after 12:01 am on Friday, August 25
    • Open the recorder cover
    • Press the “Stop Schedule” button (“C”), the screen will show the main menu options
    • Move the power switch from “INT” to “EXT”