Evaluating Reproductive Parameters of Rio Grande Wild Turkeys to Guide Policy Decisions in Texas

Historically, Rio Grande wild turkeys (Meleagris gallopavo intermedia) in south central Texas have been at lower densities than in other por-tions of the state. Within the Oak-Prairie Wildlife District of Texas, Rio Grande wild turkey regulatory restrictions are different for counties in the east- ern and western portions of the region. Due to perceived increases in turkey density in the eastern portion of the ecoregion, Texas Parks and Wildlife Department (TPWD) considered increasing the bag limit in the Rio Grande wild turkey spring-only 1-bird zone counties to increase hunting oppor-tunities. However, if regulatory changes are to be considered in the absence of estimates of abundance and harvest rate, then estimates of demograph- ic parameters will provide the basis for regulatory decision-making. Therefore, we evaluated reproductive metrics for 138 radio-marked female Rio Grande wild turkeys in four of the 10 counties in the Oak-Prairie Wildlife District's 1-bird harvest zone and two counties in the District's 4-bird harvest zone during 2016-2018. We also evaluated the influence of six nest- and female-specific covariates on survival of 131 nests. We found that reproduc-tive timing varied little between zones and across years. Nesting rates were higher in the 1-bird zone (74%) than the 4-bird zone (63%), and re-nesting rates were higher in the 1-bird zone (49%) than the 4-bird zone (25%). Conversely, nest and female success rates were higher in the 4-bird zone (18% and 15%, respectively) than in the 1-bird zone (2% and 3%, respectively). Nest survival analysis indicated higher daily nest survival in the 4-bird (0.94) than 1-bird zone (0.90). While causation is unclear, our results suggest that biologically significant differences potentially occur in basic reproductive parameters within the Oak-Prairie Wildlife District of Texas, and that the proposed regulations change may not be appropriate given reproductive rates observed in the 1-bird zone.

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