Return Rates and Reproductive Output of Captive-Reared Female Mallards

Abstract

From 1993 to 1995, we evaluated the se of captive-reared, released female mallards (Anas platyrhynchos) to increase local breeding populations. A total of 146 females in 1992, 480 in 1993, and 1,140 in 1994 was released onto pothole habitat. Return rates for females released in 1992 and resighted in 1993 were 18-24%. Return rates for females released later were much lower, ranging from 2 to 10%. Released females homed to an average of 1.17 km (SE = 0.28, n = 28) from their original release site. Released birds had low direct recover rates, which suggests poor prefledging or premigratory survival. Comparisons of reproductive output of released females to wild conspecifics were limited by low return rates. Attempting to increase local breeding populations of mallards with released birds is not a viable management technique.