Spring Harvest Management for Rio Grande Turkey
The drought and excessive heat of 2011 probably had a significant impact on Rio Grande turkey recruitment (the number of poults that reach juvenile age in the fall). Many landowners who saw fewer turkeys during the fall of 2011 and winter of 2012 are convinced that the impact was negative.
Weather conditions and predation are the two main factors influencing Rio Grande turkey nesting success and poult survival. Effects from weather and predation can be direct, indirect or interrelated; therefore, complicated and not completely understood. In spring 2011, nesting cover was probably adequate in most locations of south-central Oklahoma and north-central Texas because of fairly normal rainfall. However, the subsequent summer's drought and heat produced minimal vegetative growth, negatively affecting food for poults and hens, and perhaps fall recruitment. Landowners who witnessed poor fall recruitment are likely wondering whether they should harvest turkeys in spring 2012. Following are a few considerations.
If numbers are low, consider not harvesting turkeys. Adult male and female natural mortality rates are moderate, ranging from 38 to 46 percent. The odds are good that turkeys alive during the winter will contribute to reproductive success in the spring or at least survive until next year. Eliminating or limiting hunting mortality, which can be additive to natural mortality, is a management practice landowners can control to improve reproductive effort in the spring. Turkeys can always be "shot" with a camera.
Limit spring harvest to males only, even though bearded females are legal to hunt in Oklahoma and Texas. Loss of females (including those with beards) due to spring hunting mortality or mortality in the fall due to either sex harvest regulations has been shown to negatively affect population growth. Make sure all hunters can identify the difference between females and males.
Consider shortening the hunting season by allowing hunting for males only after the majority of females are no longer visiting males. Landowners, including those leasing their property to other hunters, have this option. This is usually well after the onset of gobbling in the spring and when the majority of females are incubating. Also, consider only hunting until noon to protect nesting females from harvest during their afternoon foraging activity. The downside to late season hunting is males may be less responsive to calls, especially during years when temperatures are warmer than normal.
Male mortality from spring hunting is widely assumed to be additive to natural mortality. Evidence suggests harvesting 25 to 30 percent of available males in the spring still allows for population growth and provides good hunting, but may shift the age structure of the male population to juvenile males. The proportion of males in a population will decline if too many are killed through hunting. If most males in the population are juveniles, reproduction might be hampered because not all juvenile males are sexually mature. Landowners observing low adult male numbers should consider reducing harvest rates to improve hunting quality and possibly future reproduction.
Spring turkey harvest regulations designed to remove a portion of males after most breeding has taken place have proven sustainable in Oklahoma and Texas. Landowners observing fewer "gobblers" on their property can implement a more conservative approach to harvest than state regulations allow. Managing harvest and habitat is the key to enjoying turkeys on your property.