MSU Extension

White-tailed deer depredation of field crops occurs throughout Michigan on an annual basis, resulting in significant economic losses. Research has suggested crop losses to deer greater than 10-15 percent of the total crop or $20 per acre are viewed as significant and are requiring remedy by Michigan producers and hunters. Campa et al. (1997) surveyed alfalfa, grain corn, soybean and dry bean producers in the Lower Peninsula and found that 20 percent of alfalfa, 25 percent of grain corn, 30 percent of soybean and 55 percent of dry bean growers had experienced substantial losses.

Northeast Michigan has been identified as a region of special concern for white-tailed deer management due to current deer population densities above DNR goals, high incidence of crop depredation and the presence of bovine tuberculosis-infected animals in the deer herd. Exclusion research conducted in the region by Michigan State University Extension in the late 1980s showed kidney bean yield losses ranging from 24 to 43 percent and alfalfa yield reductions averaging 18.7 percent. Similar research conducted in northern Michigan in 1993-94 recorded an average yield reduction of 5.23 percent in alfalfa and 9.87 percent in kidney beans caused by deer feeding.

Today, grower reported soybean yield losses to deer average 30 percent across smaller fields in northeast Michigan. However, differences may exist between real and perceived loss due to deer feeding, and no data on local soybean yield losses to deer has been published, despite increased soybean acreage and significant changes in both crop production systems and deer management policy/behavior in recent decades.

Several tools, including special DNR harvest permits and the custom harvest by USDA Wildlife Services, are available to address crop damage caused by deer. However, all available tools are currently underused. Deer Damage Assistance Permits and Deer Management Assistance Permits have been the principle tools available to producers demonstrating significant crop damage. Approximately 8,234 Deer Management Assistance Permits were issued in 2012, but only 4,008 deer were harvested. Antlerless deer hunting license sales for DMU 487 were about 19 percent below quota in 2012, and only 62 percent of antlerless licenses sold were used to harvest an animal.

In 2015, MSU Extension, with support from the Michigan Soybean Promotion Committee, will measure soybean yield loss to wildlife, principally white-tailed deer, by constructing and installing exclusion cages in soybean fields expected to experience high, medium and low deer feeding pressure based on habitat conditions noted in the literature (field size, proximity to cover, etc.).

Each of the nine fields will include four cages to act as replicates placed in a radial pattern from field center to edge, and soybean yield will be compared within and outside of the cages. Plants will be hand-harvested within the cages and from a non-caged area of equivalent size.

Study results will be summarized in a bulletin targeting soybean producers, which will also include information on available deer management tools such as field selection, special harvest permits, etc. Study results and the bulletin will be shared with producers through a deer management field day, the new MSU Extension Vertebrate Pest Workgroup, and with sportsmen through an ongoing partnership with the Michigan DNR, Michigan United Conservation Clubs and the Quality Deer Management Association.

Northeast Michigan soybean growers with interest in deer management may inquire about participating in this study by contacting James DeDecker at 989-734-2168 or dedecke5@msu.edu.

References

• “Ecological factors influencing white-tailed deer damage to agricultural crops in northern Lower Michigan,” K. Braun, MSU Department of Fisheries and Wildlife
• “An evaluation of a multidisciplinary problem: Ecological and sociological factors influencing white-tailed deer damage to agricultural crops in Michigan,” Campa et al., Transactions of the North American Wildlife and Natural Resource Conference
• Wildlife damage to crops; perceptions of agricultural and wildlife professionals in 1957 and 1987, M. Conover et al., Wildl. Soc. Bull.
• Michigan deer harvest survey report 2012 seasons, Michigan Department of Natural Resources
• A comparison of deer hunter and farmer attitudes about crop damage abatement in Michigan: Messages for hunters, farmers and managers, A. Fritzell et al.
• Deer exclusion efforts to reduce crop damage in Michigan and Northeast Wisconsin, Jim Isleib
• Michigan Deer Management Plan, Michigan Department of Natural Resources and Environment, Wildlife Division Report No. 3512