Nesting Ecology of Rio Grande Turkeys

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The nesting ecology of Rio Grande turkeys (Meleagris gallopavo intermedia) was studied on the Rob and Bessie Welder Wildlife Refuge (WWR), Sinton, Texas, during January-August 1983 and 1984. Radio telemetry was used to monitor the nesting activities of turkey hens. Twelve of 31 radio-tagged turkeys died during the study: 8 from predation, 1 from disease, 2 from trapping related injuries, and 1 from unknown causes. An annual hen survival rate of 0.73 was calculated from the total number of observation days and the known number of deaths. Ten (58%) of 17 instrumented hens reached incubation in 1983, but all nests were destroyed by predators. Two turkey broods were observed in 1983, one of 2 hens with 5 poults, the other 2 hens with 3 poults. In 1984, nesting data were gathered on 6 hens which reached incubation; 3 hatched eggs. Seven turkey broods totaling 8 hens with 40 poults were observed in August 1984. Nest sites were located in pastures deferred from livestock grazing. J. WILDL. MANAGE. 51(2):435-439 The population of wild Rio Grande turkeys, which occupies the Aransas River bottoms and surrounding uplands of the WWR, has declined from a high of approximately 700 (Watts 1969) in 1966-67 to <100 birds in 1983. In recent years, no broods have been observed by WWR personnel (J. G. Teer, pers. commun.). Although there have been several studies of the wild turkey on the WWR (Watts 1969, Smith 1977, Baker 1979b), none has directly investigated the nesting ecology of this population. Decreases in nesting attempts, nest success, or poult survival-all of which influence juvenile recruitment-could have played a part in this decline. This study was to determine whether reproductive failures by turkey hens wintering and breeding on the WWR and adjacent areas were responsible for the population decline. Financial support was provided by the Rob and Bessie Welder Wildl. Found. (WWF), Sinton, Tex., and the Coll. Agric. and Life Sci., Univ. Wisconsin, Madison. We gratefully acknowledge the assistance of several WWF students, as well as J. G. Teer, D. L. Drawe, and T. M. Yuill in trapping birds. We thank J. F. Rooke, P. H. Welder, H. Thomas, and N. E. Adams for access to their property. We also wish to thank W. Aschenbeck, of Cuero, Tex., for donating the domestic turkey eggs used in the simulated nest study. This is Welder Wildl. Contrib. 301.