Wildlife eating feed crops cause problems

Apr 27, 2012

—“At least it wasn’t a corn-fed elk!”

One night in late January, Wendy Flatt Rapp of the University of Missouri Extension Service was driving home from work. In a scene that has played out with countless drivers, a doe ran out in front of her car and Missouri had one less deer.

Rapp was fine, though the same could not be said of the deer, nor the car. She described the doe as a big, corn-fed animal who had likely been making dinner of nearby corn fields.

Referencing the ample food in the form of cropland, Rapp said in a Facebook post the next day, “I can’t imagine what an elk would have done to me or the vehicle.”

Though the story ended relatively well for Rapp— admittedly not for the deer—the issue of “corn-fed elk” is nothing to take lightly. Wildlife who help themselves to whatever’s in their reach can cause serious damage to agricultural interests as well as traffic.

Deer, hogs and other wild animals can significantly damage crops and pasture land. Both of these can be anything from a nuisance to a significant problem for ranchers and farmers.


Deer have long been a concern for crop farmers with significant documentation of the damage they can cause. Fields of highvalue commodity crops like corn and soybean make ideal “hide and eat” locations for deer.

“A lot of the deer here in Missouri eat a lot of the grain. They destroy the plants. In the fall, they hide in the corn and eat it,” said Rapp of deer in her area. The elk might catch on, too.

“The concern is the elk [the state has] reintroduced in the south will find their way north and have a lot more access to the crops.”

Deer damage crops primarily through eating key portions of the plant at important development periods and secondarily through lying on or trampling plants. Lacking top front teeth, deer damage to plants is ragged as they have to grab and pull to eat. Young plants or new growth are particularly attractive to deer, though they will also eat the crop item itself.

Other damage can include damage to young orchard trees through antler polishing in the fall or bark eating in the winter, and eating new buds, new twigs and even the fruit itself in fruit orchards.

According to a Purdue University Extension report, deer damage to crops is exceedingly common in areas where deer live. In one study, 93 percent of surveyed fields showed signs of deer. However, despite the widespread nature of deer eating crops, the economic damage they cause is not as serious as one might expect.

“For the most heavily damaged fields we surveyed, yield losses were less than $500 based on the number of damaged plants, assuming 100 percent loss for each damaged plant. A total loss of approximately 1.4 acres of corn, or 32,000 plants, would equal $500 in damage.”

Of course, this information is limited to the area of study and value of damage depends on the going value of corn. The Purdue report added that most deer browsing of soybeans did not cause yield-affecting damage.

Though deer do most of their damage to crops, they are also attracted to winter feed put out for livestock. Not only does this harm cattle who are out the feed—and the rancher who is out the cost of the feed— but wild ungulates can also spread parasites and diseases to cattle. Brucellosis spread from elk to cattle and ticks spread from deer are particular concerns.

Feral hogs

Feral hogs can be a big issue in southern states like Texas. The hogs—also called wild pigs—can not only eat stored or distributed feed for livestock, but they can severely damage feed and commodity crops, pasture land, feeding equipment and fences. Though uncommon, feral hogs also pose predation risks to small livestock such as lambs or newborn calves.

For those in hog territory, the damage they can cause to crop and pasture land is likely well known.

The damage comes from their indiscriminate diet— they will eat just about anything and everything— and their meticulously thorough approach to seeking food.

When a sounder (a group of hogs) descends on a pasture, cropland or even a suburban lawn, the destruction from their rooting can be devastating. Not only can plants in the area be eaten, uprooted, trampled or otherwise destroyed—representing a huge economic loss if the target area is cropland— but the ground itself can be severely damaged.

While digging up the ground hunting for roots, tubers and other underground edibles, hogs can leave extensive, deep trenches in the ground. Many reports exist of rooting holes and trenches so deep or wide as to make a piece of land impassible to tractors.

No dependable estimates exist of the annual cost of property damage caused by hogs in the U.S. The closest “next best” estimate places the average per hog property damage at $200 annually. Based on this estimate multiplied by the very rough estimate of the total U.S. hog population, some reports suggest $1.5 billion is the annual price tag of hog property damage.

Billy Higginbotham of the Texas A&M AgriLife Extension, however, warns that this method of estimation is suspicious at best.

“…[T]he problem there is that the assumption is made that a 40-pound hog causes as much damage as a 300-pound hog, which is unlikely. [And] if the population estimates (guesstimates) are wrong—so is the total damage estimate.”

In 2004, the total agricultural damage caused by feral hogs in Texas was priced at $52 million, according to an AgriLife survey. In addition, Texas landowners (agricultural and non) paid a combined $7 million in out-of-pocket expenses to have hogs controlled or physical damage corrected.

In addition to eating crops and harming land, hogs can cause a number of other expensive damages to agricultural interests. Acting like little (or big) four-legged bulldozers, hogs can lift up or tear through wire fences. Damaged fences can let out livestock and resources must be expended to fix them. Similar damage can result when particularly determined hogs decide to take on livestock feed bunks to get at grain.

The risk of predation of small livestock animals by large hogs—though minimal—also exists. The smell of afterbirth can attract hogs, and young lambs are the most at risk from actual predation due to their small size and frailty. However, it is more common for hogs to opportunistically scavenge on livestock carcasses if anything.

A final area of hog damage to agricultural interests lies in the impact feral hogs have on deer. Recreational activities like hunting can be a source of revenue for owners of rural or ag land. Feral hogs can negatively impact deer populations—and thereby hunting opportunities—by out-competing deer for native food sources, by scaring deer off by their very presence, and by eating winter corn from deer stands.

Control measures for bothersome wildlife consuming or destroying crops vary. Hunting is often cited as effective control measures for both deer and feral hogs, but that can be limited by season and area regulations.

The use of deterrents is another option, though effectiveness of any specific strategy is anecdotal at best. For more information on dealing with crop- or feed-consuming wildlife, contact your regional Extension office to find out about options available to you. — Kerry Halladay, WLJ Editor