Quantifying White-tailed Deer Damage to Soybean Yields in Kentucky

Wildlife are believed to cause significant losses to yields for grain farmers within the state of Kentucky. Currently, no research has attempted to quantify yield losses directly attributed to white-tailed deer within Kentucky. Previous research on deer damage to grain crops in other regions of the United States have found contradicting results, with some research showing significantly decreased yields while others showing little to no effect on yields. Within Kentucky overall the last several decades deer populations have drastically increased in many areas. Increasing deer densities have been shown to alter impacts on several ecosystems however no previous agricultural damage studies have not attempted to link deer densities to impacts on yield. With the advancements in technology and decrease in costs, we are now able to estimate deer densities at a relatively accurate level in a localized setting such as a farm or park. Pairing damage estimates to deer densities may provide more of an insight into the impacts of high density deer populations. If a correlations between deer density and yield loss exists, managers and farmers could estimate potential losses by simply estimating deer densities on their properties. Related to this, many of our management strategies to off-set deer damage involve the reduction of local populations through damage tag programs. At this time these style programs have never been tested to determine their effectiveness at reducing wildlife damage to crops. If state agencies are going to continue to use this method for deer damage control, the effects of reducing deer population on crop yields should be documented. The overall objectives of this study are to quantify the impact white-tailed deer are having on soybean yields within Kentucky, determine if deer densities are correlated with yield losses, and to test the ability of the deer damage tag program used by Kentucky Department of Fish and Wildlife Resources (KDFWR) to reduce the crop damage incurred by producers. Funds are being requested to off-set costs of hiring technicians to calculate deer densities on study farms and to hand harvest plots to acquire yield estimates. To accomplish these objectives, over two years this project will involve establishing protected and unprotected plots across multiple farms that have had a history of deer damage. On these farms, local deer populations will be estimated using two methods, a trail camera survey technique and a pellet based sampling technique. Prior to the second year of the study, we will use the estimated populations on a subset of farms to decrease deer densities by 40-60% of the estimated populations using the help of KDFWR and their annual herd health checks. After reduction we will be repeating the first year's methodology of quantifying yield loss and population densities. Using a BACI design we will be able to estimate the impact of reducing deer populations on yield losses; in essence as assessment of the deer damage tag program implemented by KDFWR.