Wildlife Damage Management, Internet Center for


Date of this Version

April 1995


Ripening field corn lost to wildlife was measured in fall 1993 in 10 midwestern states that have produced 83% of the field corn in the United States over the past 10 years. Sampling of damage was stratified by producer expectation of likely wildlife damage or unlikely wildlife damage. Damage was assessed immediately before harvest. Two plots that measured 4.5 m x 2 rows were assessed in each selected field. Of assessed fields, wildlife damage was present in 340 of 1,259 (27.0%) likely damaged fields and 108 of 1,243 (8.7%) unlikely damaged fields. As a percentage of harvested production, birds (Aves) damaged an average of 0.19% of field corn while deer (Odocoileus spp.) damaged an average of 0.23% of field corn. Unidentified wildlife caused the loss of an additional 0.27% of corn. The average yield loss was 1.73 + 0.17 bu/ha. Loss rates were greater where producers had expected damage (3.7 bu/ha) than where damage had not been anticipated (1.5 bu/ha). Among states, yield lost to all wildlife differed among 3 groups of states. Wisconsin and Missouri had the greatest wildlife-caused loss rates. Indiana, Michigan, Minnesota, and Ohio had intermediate loss rates. Iowa, Illinois, Nebraska, and South Dakota had lower loss rates. In total, an estimated 35 + 4 million bushels of corn were lost to wildlife in 1993 when harvested field corn production for the 10 selected states totaled 5.14 billion bushels. Total estimated value of field corn lost to wildlife was $92 + 9 million, when the harvested corn crop was valued at $13.3 billion in the 10 states.