Survival and Reproduction of Female Wild Turkeys in New York

Annual fluctuations of northern wild turkey (Meleagris gallopavo silvestris) populations often are attributed to high winter mortality. However, studies conducted in agricultural environments have demonstrated that seasonal survival can be highest during winter, suggesting other factors are more important to annual population change. We examined survival and reproduction of female eastern wild turkeys in south-central New York during 1990-93 and conducted a sensitivity analysis to determine the relative importance of demographic parameters to annual population change. Seasonal survival rates (n = 238) were 0.800 for spring, 0.855 for summer, 0.834 for fall, and 0.873 for winter. Fall survival rates varied by years (P < 0.01) and were higher during years of above average hen success. Annual survival rates averaged 0.498, and crude annual mortality rates (M̂) averaged 0.321 for predation and 0.117 for poaching, hunting, and wounding combined. Subadult females had lower nesting rates (P = 0.002, n = 201), lower renesting rates (P = 0.001, n = 115), and lower hen success rates (P = 0.02, n = 196) than adult females. Nest success averaged 37.9% (n = 232) and was highest (P = 0.005) during years with average to below average May rainfall. We observed annual variation in nest success (P = 0.001), hen success (P = 0.003), and hatching rates (P = 0.04). Poult survival averaged 40.0% (n = 605) and did not vary among years (P = 0.73). Nest success was the primary factor contributing to annual population change. We suggest that annual fluctuations of northern populations in mixed agricultural and forested environments rarely result from variability of annual survival and may result from variability of annual nest success and poult survival. Northern populations subjected to infrequent severe winters in mixed agricultural and forested environments likely would benefit more from enhancement of nesting and brood-rearing habitat.