Frequency List

The following frequencies (in MHz) have been used for wildlife tracking:
30.0500 L1
30.0600 L2
30.0700 L3
30.1700 L4
30.1800 L5
30.1900 L6
30.2000 L7
30.2100 L8
30.2200 L9
30.2300 L10
30.2400 L11
30.2500 L12
164.4375 H1
164.4625 H2
164.4875 H3
164.5125 H4
164.5375 H5
164.5625 H6
164.5875 H7
164.6125 H8
164.6375 H9
164.6625 H10
164.6875 H11
164.7125 H12

Multi Use Radio System. Some have suggested using MURS for tracking. Though specifically not authorizied for use in aircraft, some feel MURS would be suitable for birds. MURS is authorized for the frequencies 151.820 MHz, 151.880 MHz, 151.940 MHz, 154.570 MHz, and 154.600 MHz The authorized bandwidth is 11.25 kHz on frequencies 151.820 MHz, 151.880 MHz and 151.940 MHz. The authorized bandwidth is 20.0 kHz on frequencies 154.570 and 154.600 MHz. These frequencies are in a part of the spectrum that should make them physically suitable for avian telemetry.

From the USGS at http://www.npwrc.usgs.gov/resource/2002/radiotrk/convent.htm

Transmitters. Each radio transmitter consists of electronic parts and circuitry, usually including a quartz crystal tuned to a specific frequency. Crystals come in different degrees of shock-resistance, and for animals such as wolves that lead aggressive lifestyles, high-shock resistant crystals are usually used.

Signals can be either continuous, which sounds through a speaker like a high-pitched whine, or pulsed, which sounds like a series of "beeps." Pulsed signals are usually used at rates of 30-120 per minute. Lower pulse rates yield longer transmitter life. Pulse widths can also vary, with 18 milliseconds being the minimum that is easily tracked. The narrower the pulse, the longer the life.

Transmitting Frequency. Frequencies used in wildlife telemetry usually range from 27 MHz to 401 MHz. VHF transmitters typically give a ground-to-ground range of 5-10 km which is increased to 15-25 km when received aerially (Rodgers et al. 1996). Lower frequencies propagate farther than higher frequencies since they reflect less when traveling through dense vegetation or varying terrain (Cederlund et al.1979; Mech 1983). However, lower-frequency signals (e.g., 32 MHz) consist of longer wavelengths, which increase the size of the transmitting and receiving antennas necessary for detecting them. This has implications for feasibility and receiver portability (see below).

The commonest frequency ranges used for VHF tracking are 148-152 MHz, 163-165 MHz, and 216-220 MHz. The higher frequencies bounce more (e.g. off mountains) but have the advantage of requiring smaller antennas. Whatever frequency is selected, individual transmitters are usually tuned 10 KHz apart to allow distinctiveness despite signal drift (1-2 KHz) due to temperature and battery fluctuations (Mech 1983).

Some wildlife tracking (primarily birds) is also done at frequencies of 216.010, 216.030, and 216.080 MHz.

Governing Regulations
[Code of Federal Regulations]
[Title 47, Volume 1, Parts 0 to 19]
[Revised as of October 1, 1998]
From the U.S. Government Printing Office via GPO Access
[CITE: 47CFR5.108]

[Page 599]
                       TITLE 47--TELECOMMUNICATION
                     Subpart C--Technical Standards
Sec. 5.108  Wildlife tracking and ocean buoy tracking operations.

    Except as provided in Secs. 5.101, 5.102, 5.103 and 5.106, the use 
of frequencies in the bands 40.66-40.70 MHz and 216-220 MHz for the 
tracking of and telemetry of scientific data from ocean buoys and animal 
wildlife are subject to the following conditions:
    (a) All transmitters used at stations first licensed after February 
18, 1975, shall comply with the technical requirements in paragraph (b) 
of this section and shall be verified as provided in Sec. 5.109.
    (b) Technical requirements for transmitters used for these 
operations are as follows:
    (1) In the 40.66-40.70 MHz frequency band, the bandwidth required 
for frequency tolerance plus the occupied bandwidth of any emissions 
must be adjusted so as to be confined within this band, except as 
permitted by paragraph (b)(6) of this section.
    (2) In the 216-220 MHz frequency band, the carrier frequency shall 
be maintained within 0.005 percent of the assigned frequency.
    (3) Classes of emission will be limited to A0, A1, A2, F1, F2 and/or 
    (4) Occupied bandwith shall not exceed 1 kHz.
    (5) The maximum carrier power shall not exceed 1 milliwatt for 
airborne wildlife applications, 10 milliwatts for terrestrial wildlife 
applications and 100 milliwatts for ocean buoys.
    (6) The mean power of emissions shall be attenuated below the mean 
output power of the transmitter in accordance with the schedule shown in 
Sec. 5.103(b) of this subpart.

[40 FR 2814, Jan. 16, 1975; 40 FR 6474, Feb. 12, 1975; 48 FR 52738, Nov. 
22, 1983; 63 FR 36602, July 7, 1998]

    Effective Date Note: At 63 FR 36602, July 7, 1998, in Sec. 5.108, 
paragraph (a) was amended by removing the term type accepted and adding 
in its place verified, effective Oct. 5, 1998.