Livestock Monitoring
Brenda Land, Project Leader
Tracking Movements of Domestic Sheep with
Global Position System —
an Application for Public Land Managers
Mark Moulton, Fisheries and Watershed Program Leader
Seth Phalen, Range Management Specialist
Sawtooth National Recreation Area, Idaho
Executive Summary
A core objective of most
allotment management plans on public lands administered by the U.S. Department
of Agriculture (USDA) Forest Service is the movement and use of permitted
livestock to achieve the resource objectives desired, and/or prevent conflicts
with other uses. However, monitoring and documenting livestock movements
and use through a grazing season is expensive and difficult, typically
requiring several field reviews by qualified resource specialists. This
demonstration project evaluated the use of the Global Positioning System
(GPS) to achieve these monitoring objectives on sheep allotments.
The cost, size, and accuracy
of GPS have all converged in recent years to make their use for tracking
animal movements practical. During the summer of 2001 movement of a herd
of sheep grazing in the Smiley Creek Sheep Allotment within the Sawtooth
National Recreation Area (NRA) in Idaho, was recorded using the GPS_2200L
datalogger.
Two sheep within the band were
collared. The very high frequency (VHF) /GPS datalogger collars are designed
and sold by Lotek Wireless Inc. of Ontario, Canada. This report addresses
the procedures and success of applying the technology. The underlying science
of GPS is not presented.
Both collars performed without
compromise for 128 days between early June and mid-October, 2001. Ninety-four
percent of the position attempts were successful over the period despite
the mountainous and forested conditions. Launching and retrieving the data
was less than intuitive, as with many new technologies; but once understood,
the process was effective. The final data product includes animal positions,
which are date and time stamped throughout the grazing season.
The two collars were launched
with different sampling frequencies - every two hours with one, and
every four hours with the other. Although a finer temporal resolution provides
greater route detail, further analysis will be required to determine if
the added detail is meaningful for day-to-day allotment management. Memory
capacity of the collars could have easily accommodated an even more frequent
sampling.
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