Northern Prairie Wildlife Research Center
Captain Michael C. Carter, Air Force Research Laboratory, Noise Effects Branch, 2610 Seventh Street, Building 441, Wright-Patterson AFB, OH 45433-7901 USA and John McQuiddy, McQ Associates, Inc., 1551 Forbes Street, Suite 100, Fredericksburg, VA 22405 USA
The public continues to raise concerns over the possible effects of noise resulting from low-level military aircraft. That is why McQ Associates, Inc. developed a new Animal Noise Monitor (ANM) collar for the U.S. Air Force Research Laboratory. The current ANM collar configuration will be tested initially on free-ranging bighorn sheep (Ovis canadensis) in Idaho to monitor their reactions to low-level military aircraft overflight events, beginning winter 1997.
The Animal Noise Monitor collar is a combined releasable collar, electronics and battery housing unit. Features include two-way VHF communications, GPS locating, accelerometer, acoustic noise level and event monitoring, a heart rate monitor, and remotely-commanded collar release. Each of these features will be briefly discussed.
Two-way VHF Communications: A VHF transceiver with an integrated antenna within the battery/electronics housing will transmit nominally at 142.25 MHZ. Transceiver range will be VHF line of sight. When a correctly addressed data retrieval command is received, the collar will use the transmitter to send packets of collar data, time stamps, and check-sums.
GPS: A GPS navigation system will be programmed to automatically compute a GPS position every 4 hr; compute a GPS location on command from a remote processing unit; and compute a GPS location immediately after acoustic, accelerometer, and heart rate data are downloaded.
Accelerometer: Collects 240 accelerometer samples per hour, calibrated to cover the range of animal movement from "still" to "jumping/running", and then displays the data for the operator as an accelerometer average and accelerometer max. Accelerometer data will be presented to the operator in conjunction with acoustic events, thus providing animal physical reactions to those events. Accelerometer data will be displayed for the period starting 10 min before through 30 sec after an acoustic event.
Acoustics: Hourly noise levels will be calculated and provided from samples taken four times per second. An acoustic event will be defined as being greater than 75 dB, having greater than 1 sec duration, and be at least 20 dB greater than the average noise level for the last 10 min. If an "event" occurs, pertinent noise, sound exposure level, duration, heart rate, and accelerometer data will be recorded and placed in memory for commanded retrieval.
Heart Rate Monitor: The sensor under development by SAIC is a non-intrusive device that will collect heart rate data from the animal at regular intervals with specific focus and display in conjunction with acoustic events, similar to accelerometer monitoring.
Collar release: The ANM collar will be capable of a remotely-commanded release, triggered via VHF transmission. GPS data from the collar can be used to locate the collar. The 2.5" wide collar attached to the electronic and battery housing will be adjustable in length. The collar will be a stitched, double-layered design of impact, abrasion, and tear resistant materials which are rated "excellent" for weather, oxidation, and ozone resistance in temperature ranges from -40 to 150°F. The collar and housing combined will weigh approximately 4.7 lbs.