Reproductive ecology of Rio Grande wild turkey in the Edwards Plateau of Texas

摘要

The abundance of Rio Grande wild turkeys (Meleagris gallopavo intermedia) inthe southeastern Edwards Plateau of Texas has declined since the late 1970s. Becauseknowledge of reproductive rates is important to understanding the dynamics of apopulation, radio-tagged hens were monitored during the 2005?2007 reproductiveseasons to evaluate and compare reproductive parameters from areas with both decliningand stable population trends.During January?March of 2005?2007, turkey hens were captured and radiotaggedon 4 study areas; 2 within a region of stable turkey populations, and 2 within aregion of declining populations. Monitoring occurred from January?July each season todetermine nest- site locations. Nesting attempts, nest fate, clutch size, initiation date,and nest age were recorded. Nests were monitored ?3 times weekly in order to estimateproduction parameters and daily nest survival. Poults were captured by hand and fittedwith a 1.2 glue-on transmitter and monitored daily to estimate daily survival.Estimates show production was greater in stable regions than declining regions ofthe Edwards Plateau. Eighty-four percent of hens attempted to nest in the stable region and 67% attempted in the declining region. Eighteen of 102 nests were successful (?1egg hatched), in the stable region and 7 of 60 nests were successful in the decliningregion. Nest-survival analysis showed an influence of temporal variation within years,yet no differences in nest survival were detected between stable and declining regions.Poult survival also showed no difference between regions.The 2 overall objectives of this study were to determine if nesting parameters andnest survival were limiting factors in Rio Grande wild turkey abundance in the EdwardsPlateau. Regional differences in production suggest the cause of the decline in thesoutheastern portion of the Edwards Plateau could be associated with lower reproductiveoutput and consequently, success. Regional differences in nest survival were notdetected, thus not likely to cause differences in turkey abundance between regions.