Dept. Forestry and Natural Resources
715 W. State Street
W. Lafayette, IN 47907
(765) 494-3590
FAX: (765) 494-9461

Project Partners

Amount and Timing of Wildlife Damage

We sampled corn and soybean fields that were representative of the distribution of field sizes in the study area. Technicians walked field transects (along the field edges and interior) and surveyed each field approximately once per month from plant emergence until harvest. Survey crews documented all plants that exhibited any sign of wildlife-caused damage visible from transects. Where depredation events (any previously unrecorded damage to a single plant caused by wildlife) were documented, crews recorded the number of plants damaged, wildlife species responsible, amount of leaf area damaged, amount of seed damage, height of damage, growth stage of plant at the time of damage, and remaining yield. All documented damage was marked clearly with paint to avoid recounting during subsequent surveys.

Researchers documented a total of 582,515 depredation events in 149 of 160 corn and soybean fields (93%) surveyed over the growing seasons of 2003 and 2004. No wildlife damage was observed in 5 corn fields and 6 soybean fields. Our surveys in soybean fields yielded 131,556 depredation events in 2003 and 377,859 depredation events in 2004. The average number of soybean plants damaged per field was 8,490 (SD = 23,708) and the maximum number of plants damaged in a single soybean field was 162,453. White-tailed deer (61%) and groundhogs (38%) were most often responsible for damage to soybean plants. Eastern cottontail, raccoon, small rodents, and unidentified species combined were responsible for less than 2% of the total damage to soybean plants. We detected no measurable wild turkey damage to soybeans. Damage to soybeans remained relatively constant throughout the growing season as long as plants were green and succulent.

Our depredation surveys in corn fields yielded 24,623 depredation events in 2003 and 48,477 depredation events in 2004. The average number of corn plants damaged per field was 731 (SD = 1,440) and the maximum number of plants damaged in a single field was 8,357. Raccoons were responsible for 87% of the observed damage to corn, an amount more than 8 times greater than damage caused by deer. Small mammals (e.g. eastern cottontail, fox squirrel, thirteen-lined ground squirrel, and chipmunk), beaver (Castor canadensis), birds, and other wildlife had little effect on field corn yield in our study area. We detected no damage to corn by wild turkey. Deer damaged corn steadily from plant emergence through harvest (October). Conversely, raccoons rarely damaged corn until the beginning of the corn reproductive stages (early to mid-June); raccoons subsequently caused substantial amounts of damage until harvest (October).