
A good club turn-out heard Dr. Colin Gooch detail radio equipment used to track birds during daily feeding habits and migration. Three systems were explained: Radio Tracking, good for short range, A Position Logging GPS receiver gives good data, but must be retrieved from the bird to access the data, and for the longest range measurements, Satellite Tracking, which yields good data but is expensive. Of course, small birds can only be expected to carry small transmitters which must not be more then 5% of the birds body weight. The limiting factor is generally the weight of the battery. These transmitters are only detectable over a short range of perhaps a hundred meters, so not useful for GPS or Satellite tracking. Dr. Gooch showed maps of various feeding patterns exhibited by types of gulls and also the long range migration patterns of those birds that travel to western Africa and sometimes beyond.