We tested prototype GPS collars on 8 free-ranging wolves (Canis lupus) and
3 white-tailed deer (Odocoileus virginianus) for varying periods between Fe
bruary and August 1997, We programmed the 920-gm collars to make a location
attempt 6-96 times per day. The collars were designed to be remotely relea
sed from the animal and the data were then downloaded to a desktop computer
. The collars produced 47-1,549 locations each during 11-41 days; locations
were successful in 26-95% of the attempts ((x) over bar = 70%). Eight coll
ars released successfully. Three collar-release failures were caused by con
densation. Two collars had GPS antennas that were improperly attached and d
id not collect data. Life was as long as, or longer than, expected in 4 col
lars, less than expected in 5 collars, and unknown in 2 collars. Limitation
s of this type of collar include brief life if programmed at short location
-attempt intervals (less than or equal to 1 hr) and possible drop-off failu
re. Nevertheless, the large volume of data we collected with no field telem
etry effort demonstrates the potential for this type of GPS collar to answe
r questions about movements of medium-sized mammals.