Survival and Reproduction of Pen‐Reared vs Translocated Wild Pheasants Phasianus colchicus

Abstract

We compared vital rates of two different ring‐necked pheasant Phasianus colchicus stocks (pen‐reared and wild) and assessed effects of predator control on these pheasants released into current range. Wild (31 males and 112 females) and pen‐reared (230 males and 1,059 females) ring‐necked pheasants were released in spring into two areas in southern Idaho during 2000–2001 to augment low resident populations. Wild female survival (value ± 95% CI) from 1 March‐1 October was significantly greater than that of pen‐reared females in both 2000 (0.40 ± 0.14, N = 62 vs 0.04 ± 0.07, N = 49) and 2001 (0.43 ± 0.16, N = 40 vs 0.08 ± 0.10, N = 40). Of 134 documented deaths of radio‐marked female pheasants, 54% were due to unknown predation, 26% to mammalian predators, 12% to avian predators, 4% to natural causes, and 4% were human caused. Wild females had a 0.23 ± 0.09 (N=88) nesting rate and pen‐reared females 0.28 ± 0.18 (N = 25). During 2001, predators were removed within our study areas. Survival of wild male pheasants increased after predator removal (0.20 ± 0.35, N = 6 vs 0.70 ± 0.28, N = 10), but survival did not increase for either stock of female pheasants after predator removal. Predator control did not increase the number of hens surviving to reach the nesting season (1 May), nesting rate or nest success. Wild female pheasants were seven times more likely to survive translocation to 1 October, 10 times more likely to survive to the nesting season, eight times more productive, and one‐third as expensive per egg hatched than pen‐reared females. Low survival, poor productivity and higher costs of spring‐released pen‐reared female pheasants strongly suggest that this is an inappropriate management tool for increasing pheasant numbers.