The use of satellite telemetry to track Greater Snow Geese

We compared the performance of two models of satellite transmitters and two types of attachments to track Greater Snow Geese (Chen caerulescens atlant ica) from their Arctic breeding grounds to their wintering areas along the Atlantic coast of the United States. Six birds were fitted dth a Toyocom T- 2038 attached with a back-mounted harness (141 g, vertical upward antenna) in 1993, 5 with a back-mounted Telonics ST-10 (116 g, horizontal antenna) i n 1994, and 11 with a Telonics ST-10 fixed on a neck collar (99 g, vertical downward antenna) in 1995. The transmitters represented 3.5-5.2% of goose body mass. All transmitters operated on a 84-96 s repetition period with a duty cycle of 8 h on and 16 h off and were tracked using the Argos system. Six birds tall dth harness attachment were shot by hunters; 12 could not be tracked for the entire migration because of mortality, radio loss, or radi o failure; 4 tall with neck collar attachment reached the wintering grounds . Overall, we obtained 2.4-7.2 locations/goose/day with a greater number at higher latitudes than at lower ones. In 1993, 75% of locations had a quali ty class (LC) greater than or equal to 1, while only 18-20% of locations we re similarly classified in 1994-1995. We could not evaluate the relative ef fect of the antenna orientation and the intrinsic characteristics of the tr ansmitters on the PTT performance and location quality. The difference betw een true and estimated locations ranged on average between 1.4 km for LC 2 to 23 km for LC B. Geese fitted with harnesses spent more time in comfort m ovements than unmarked birds. We recommend that harnesses be avoided for ge ese. Satellite telemetry is adequate to track long-distant movements of mig rants or to locate unknown critical areas (breeding, wintering, etc.) but n ot for detailed studies on habitat use or local movements.