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Capture & Tracking Techniques In North Carolina, pintails are a coastal oriented species as the overwhelming majority of the pintail harvest occurs in 6 coastal counties.
We thus focused our marking efforts along the coast at several locations where suitable trapping sites could be found. Pintails were caught with both rocket nets and swim-in traps and then fitted with transmitters. The heaviest birds with adult plumage characteristics were chosen to be fitted with transmitters. All were kept overnight for observation and then released at the capture site. Other pintails captured were leg-banded and released on-site. Birds were marked at 4 different locations: 4 from Mattamuskeet National Wildlife Refuge (NWR) (Hyde Co.), 3 from Pocosin Lakes NWR (Washington Co.), 2 from Pea Island NWR (Dare Co.) and 2 from Pine Island Hunt Club (Currituck Co.).
The satellite transmitters (called PTT’s or Platform Transmitter Terminals) are manufactured by Microwave Telemetry, Inc. and weigh 20g. The weight of the transmitter is critical as the overall weight of the transmitter/harness package should not exceed approximately 3-4% of the weight of the bird. Until very recently, technology did not exist that allowed for such a lightweight package with an extended battery life. The transmitters rest on the back of the bird and are attached with a Teflon ribbon harness. Birds appear to adapt well to the transmitter package although we do suspect that it takes several days before the bird has adjusted and preened in the harness to their liking.
Transmitters
may be programmed an infinite number of ways, depending upon study
objectives. Because we are primarily interested in large-scale
movements over the course of 1 year, our transmitters are programmed
to send a signal every 65 seconds for eight hours every six days.
This routine conserves battery power and should allow researchers to
track
the pintails through spring migration, breeding, and the following
fall migration. Signals are picked up by an ARGOS tracking system
receiver attached to several NOAA polar-orbiting weather satellites.
SERVICE ARGOS is a cooperative venture under the joint management
of France's
Center of National Space Studies, and the United States of America's
National Oceanic and Atmospheric Administration (NOAA) and the National
Aeronautics and Space Administration (NASA). The purpose of ARGOS
is to allow researchers to remotely collect environmental data on a
wide
range of subjects, including: meteorology, oceanography, and animal
ecology. The data is then relayed down to earth where locations are
determined by ARGOS and then finally where it is sent to project
personnel. |
