NECK COLLAR RETENTION IN DUSKY CANADA GEESE
--A total of 4965 Dusky Canada Geese (Branta canadensis occidentalis) were neckcollared on the Copper River Delta, Alaska, in 1984-1990. Collar retention rates for adult geese were obtained from examination of 910 recaptures. The effects of sex, collar age and collaring year on retention rates were determined using logit models. As there was a significant interaction between the effects of sex and collar age on retention rates, the sexes were modeled separately. The average annual retention rate for female geese (0.875 ___ 0.163 SE) was independent of all effects considered. Retention rates for males was influenced by collar age and the year collared. It is concluded that collar losses were substantial and that losses pecific to the years modeled should be considered in any population model. RETENCI•N DE ANILLOS EN EL PESCUEZO POR PARTE DE INDIVIDUOS DE BRANTA 1⁄2ANADENSIS OCCIDENTALIS Sinopsis.--Entre el 1984-1990 un total de 4965 individuos de gansos del Canada (Branta canadensis occidentalis) fucron anillados cn la pescuezo en el delta del Rio Copper, Alaska. La retenci6n de las anillas, pot parte dc adultos, fue obtenida del estudio de 910 individuos rccapturados. E1 efecto dcl sexo, edad dc la anilla y afio de la anillada, en la tasa de retcnci6n de anillas, fuc determinada utilizando modelos dc "logit." Como hubo una interaccion significativa entre el efecto del sexo y edad de la anilla, en la tasa de retenci6n, se hicieron modelos separados para ambos sexos. La retenci6n promcdio anual para hembras (0.875 + 0.163 EE) result6 set indepcndiente dc todos los otros efectos considerados. La tasa dc rctcnci6n cn los machos fue influcnciada pot la cdad de la anilla y el afio dc anillamiento. Sc concluye quc las p6rdidas de las anillas fue sustancial, y quc los extravlos en aftos particulates deben set consideradas en cualquier modelo poblacional. Neck collars have been used to mark geese for several decades (Marion and Shamis 1977). Observations of these birds have provided much valuable information about population dynamics (Hestbeck and Malecki 1989, Rusch et al. 1985), migration (Craven and Rusch 1983, Koerner et al. 1974, Raveling 1978, Trost et al. 1980), and behavior (Macinnes and Lieff 1968). Recently, observations of marked geese have been applied in methods used to estimate survival probabilities (Ebbinge and van Biezen 1987, Hestbeck and Malecki 1989, Raveling and Zezulak 1988, Rusch et al. 1985, Yparraguirre 1982), statistics that have traditionally been calculated from models utilizing band recovery data (Brownie et al. 1985). These models generally do not account for marker loss (Brownie et al. 1985, Pollock and Raveling 1982), which is probably of little consequence for-short lived species. In the case of potentially long-lived animals such as geese, however, marker loss may severely affect survival estimates (Nelson et al. 1980). The Dusky Canada Goose (Branta canadensis occidentalis), which nests primarily on the Copper River Delta, Alaska, and winters in the Willamitte Valley in Oregon and southwestern Washington, has steadily declined in number since 1979. Harvest was restricted in 1984 and is
Observations of Neck-Collared Canada Geese Near John F. Kennedy International Airport, New York
Canada geese (Branta canadensis) often cause significant damage when they strike aircraft. They are responsible for a reported minimum of $2.6 million in damage per year to civil aviation in the United States. Knowledge of goose movements in relation to airports would allow wildlife managers to allocate time and funds to manage those populations that pose the greatest threat to aircraft. We placed alpha-numeric neck collars on 300 Canada geese within 8 km of both John F. Kennedy International Airport (JFKIA) and LaGuardia Airport in New York, New York. We conducted weekly observations for 2 years within a 12-km radius of JFKIA at locations used by the geese. At the conclusion of the study, 45% of the collared geese remained within an 8-km radius of JFKIA, and four were killed at JFKIA during wildlife control operations. We observed birds at their original banding sites 75% of the time, and within 5 km of the banding location 95% of the time. Geese that remained in the study area were re-sighted at a mean straight-line distance of 3.6 (±3.1) km from their original banding location. We note that 78% of the re-sighting locations used by geese were within 8 km of JFKIA and that movements of these geese could take them over or onto JFKIA. Oiling goose eggs to kill the embryos, rounding up of flightless birds within 8 km of the airport, and bird-control activities at JFKIA and nearby areas all should be continued to reduce the probability of a catastrophic bird strike between aircraft using JFKIA and local Canada geese.
The Marking of Ruffed Grouse for Field Identification
The possibility of identifying individuals of any species in field research work on wildlife simplifies innumerable problems, many of which may not otherwise be solved. With some problems and some species, the use of leg bands suffices, but when field identification of a species like the ruffed grouse is required, bands are not enough. Leg bands do have a definite value in ruffed grouse research, however, and all grouse brought to hand in the New York work are banded on both legs before release. When these birds are