Survival Rates of Hand-Reared Mallards Released on 2 Private Farms

Abstract

I derived survival rates of hand-reared mallards (Anas platyrhynchos) released on 2 private farms in Maryland using stochastic models. Survival rates of summer-banded young for the first hunting season to the time of postseason banding in February averaged 0.29 and 0.47 for males and females, respectively. Survival rates of adults banded postseason generally were lower (f difference = -0.18, P < 0.02) than those of wild mallards banded postseason in Maryland. Survival rates of hand-reared adult males averaged 0.35; female survival rates were 0.27 at Remington Farms and 0.55 at Money Point Farm. Survival rates of handreared mallards were lower and nonhunting mortality rates higher than those of wild mallards. J. WILDL. MANAGE. 53(1):114-118 Releasing hand-reared mallards is controversial in the Atlantic Flyway (Atl. Waterfowl Counc., unpubl. min. of annu. meetings, 1979, 1980). Released birds may have traits that lead to low survival in the wild and they may contaminate the wild gene pool (Banks 1972). Previous estimates of survival rates for hand-reared mallards used early unsophisticated methods based on invalid assumptions (Brownie et al. 1985:8). My objective was to estimate survival rates, derived from stochastic models, of handreared mallards released on 2 private farms in Maryland. I thank A. G. Decker, Jr. for allowing me to use hunting and banding records, and his staff for assisting with bird banding. J. D. Nichols and the U.S. Fish and Wildlife Service's (USFWS) Bird Banding Laboratory assisted with compilation and analysis of data. Remington Arms Company, Incorporated, funded the study. STUDY AREA AND METHODS Mallard releases were made on Money Point and Remington F4rms located on Maryland's Eastern Shore. Money Point was a 95-ha grain farm, located in Cecil County on the north shore of the Sassafras River. Remington Farms was a 1,330-ha grain farm and wildlife management and demonstration area, located in Kent County, and bordered an estuarine creek of the Chester River. Money Point Farm released about 1,000 mallards annually. Each spring 80 carry-over second-year females and 20 males were selected as breeders. Ducklings were raised in a brooder house for 10 weeks, then released (about midJul) in groups on 3 ponds and the creek shore. Mallards were fed until 10 days before the start of the hunting season. Remington Farms released about 5,700 mallards annually. One-day-