Reproductive Parameters of Wild Turkey Hens in North Missouri

Abstract

Reproductive parameters of eastern wild turkeys (Meleagris gallopavo silvestris) were studied on a 52-km2 area in north Missouri during 1981, 1982, 1984, and 1985. Nest success, hen success, nesting rates, clutch size, fate of nests, and poult mortality were estimated from a sample of 127 radio-instrumented hens. Nesting success and hen success were highly variable among years. Average nest success was 30.6% with hen success averaging 37.8%. Few differences were detected between adult and subadult hens in nest success or hen success. Predation was the major cause of nest losses. Renesting rates averaged 55.0% in 1981, 1982, and 1985; but only 14.0% following a late spring in 1984. Both renesting rate and nesting chronology appeared to be affected by early spring temperatures. Poult mortality averaged 61.9% at 4 weeks post-hatch. Reproductive success in this study was lower than has been reported elsewhere in the subspecies range. J. WILDL. MANAGE. 51(3):535-540 Reproductive parameters of recently reintroduced eastern wild turkey populations have been studied extensively (Eichholz and Marchinton 1975, Little and Varland 1981, Clark 1985, Miller et al. 1985). Reproductive success and nesting ecology also have been examined in indigenous turkey populations in the south (Williams et al. 1968, Hon et al. 1978, Everett et al. 1980, Metzler and Speake 1985, Speake et al. 1985). Porter (1978) investigated reproduction in an established, but rapidly expanding, turkey population in Minnesota, the northern boundary of the eastern wild turkey range. To date no studies have reported reproductive parameters from stable turkey populations in the Midwest. Eastern wild turkey densities in this region of the country are among the highest reported for the species, exceeding 30 birds/ km2 of timber (Kurzejeski et al. 1987). Effective management of these populations requires quantitative estimates of reproductive success and poult mortality. The purpose of this paper is to report reproductive parameters and poult mortality estimates for an established wild turkey population in north Missouri, and to examine the relationship between yearly breeding chronology and temperatures. Assistance was provided by E. A. Keyser, J. S. Fleming, B. J. Otten, D. J. Newswanger, and K. C. Ehlers. E. R. Jayne, C. J. Scriven, M. E. Wade, C. Turner and numerous others provided access to their private lands that was essential in conducting this study. G. S. Olson and S. L. Sheriff assisted with data analyses. Partial funding for this study was provided by the State Chap. and local chapters of the Natl. Wild Turkey Fed., and by the Fed. Aid Wildl. Restor. Act, under Pittman-Robertson Proj. W-13-R. The Wildl. Res. secretarial staff typed drafts of this manuscript. K. C. Sadler reviewed the manuscript. STUDY AREA AND METHODS Wild turkey hens were captured using cannon nets during 4 winters (1980-81, 1981-82, 198384, and 1984-85). Each hen was aged (subad or ad), instrumented, and released at the capture site. A 140-g mortality-sensitive radio package, operating on 164-165 MHz band, was attached using a back-pack harness. The radio package was powered by a lithium battery with an expected life of 24 months. Instrumented hens were monitored daily on a 52-km2 study area about 8 km west of Kirksville in Adair County, Missouri. A more detailed description of the study area can be found in Kurzejeski et al. (1987). We monitored hens using an ATS programmable-scanning receiver and a 4-element handheld Yagi antenna. Prior to 1 April, mortality was monitored daily by taking single readings. Beginning 1 April, triangulation occurred daily. Highly localized movements were assumed to be indicative of nest initiation (Porter 1978:61).