This guide helps diagnose what's digging, tunneling, feeding, and otherwise disturbing turf grasses. Use the links above the graphic to find more information about many of the offenders and be sure to check out our Problem Wildlife page for more details on other wildlife conflicts around homes and farms.
Producers all across the state ask this question every year: crops that were growing healthy one day can be shreaded or knocked over the next, ruining chances for a yield on small, and sometimes large scales. Sometimes, the likely culprit is still visible, or left behind evidence of its presence like tracks or feces. But more often, the evidence is circumstantial, and producers have to diagnose the likely cause and consider options for abating the issue.
Researchers from Purdue University extension conducted a detailed research study in a corn-bean rotation system in Northern Indiana to help provide some insights into what causes crop depredation and how to identify and diagnose the likely culprits. Here are the key findings from that study:
Check out the guide to Identification of Wildlife Crop Depredatation produced by the Indiana study for help diagnosing damage on your farm.
The likely culprits on your own farm will depend a lot on what other sorts of cover is found around your fields. In the Indiana study, raccoons were really problematic because there were high raccoon densities in isolated woodlots in the middle of the crop fields. Producers in some parts of Iowa may face similar problems, whereas in other parts of the state with fewer trees, raccoons may not be a major issue. A study in Iowa described in an Iowa DNR brochure on wild turkeys found that although many producers in Northeastern Iowa suspected turkeys were depredating crops there, little damage by turkeys was documented. Rather, turkeys were just conspicuously feeding on insects and earthworms in the crop fields.
For help diagnosing wildlife depredation issues in your fields, check out the Iowa DNR website on wildlife damage management. There you can find an article on identifying crop damage, abatement techniques to deal with damage, information on options available to producers with deer damage, and more resources on wildlife damage in Iowa.
Pee-Yew! It's fall and you've caught a whiff of that unmistakable pungent smell drifting on the night air that could only belong to the skunk. Skunks, now classified in the family Mephitidae, like members of its former family Mustelidae, the weasels (mink, weasel, badger, otter, etc.), emit an oily musk from their anal glands. Members of these families use musk to mark territories and den sites, and attract a mate. But, in the case of skunks, they can release a potent mist or stream, at close range and up to 20 feet, to defend themselves against predators!
Iowa has two species of skunks: the striped skunk and the spotted skunk. The latter, also known as a "civet cat", is smaller than the striped skunk, has white spots and shorter, broken white stripes against black fur, and is listed on Iowa’s endangered species list. Little is known about where they may still be found in Iowa. With the loss of small farms, diversified agriculture, and the lack of rodent prey attracted to readily available grain, once stored in open cribs, the “civet cat” has all but disappeared from Iowa’s farms and countryside. Meanwhile, the striped skunk has remained ubiquitous, occasionally to the chagrin of a dog or homeowner.
Striped skunks are typically nocturnal, but during times of increased feeding, such as spring when the female is pregnant and fall, when fattening up, they can be seen earlier in the day or evening. Seeing a skunk in daylight is not necessarily an indication of rabies and should not cause undue alarm. Pay attention to the overall health and behavior of the skunk, and if it appears to be going about its business, do not disturb it and maintain a respectable distance.
Striped skunks typically have litters of 4 to 6 young born between May and June. The young stay with the female until fall, when they begin to disperse in search of their own territories and winter den sites. This behavior, known as the “fall shuffle” puts roaming skunks at risk, increasing encounters with humans, our pets, and predators. As evidence of this shuffle, notice how many road-killed skunks and raccoons you see during the fall.
Striped skunks have a very good sense of smell, and being omnivores, consume a varied diet, preferring insects and their larvae. They also consume eggs, berries and other fruits, and in winter and early spring when other food is scarce, small rodents. In late summer and fall, skunks can cause damage to lawns as they search for insect larvae, such as white grubs. The damage is distinguishable from that caused by raccoons, as the sod appears as if someone has neatly rolled it back with the intent of transplanting it elsewhere. Any control of this damage must first begin with the control of white grubs in the soil. Contact your local County Extension office or Horticulture Extension for the appropriate timing and chemicals necessary to control grubs. This feeding activity in the fall builds up fat reserves for winter. Skunks do not hibernate but will sleep for a week or two during severe winter weather.
During the fall, skunks, as well as woodchucks, raccoons, rabbits, chipmunks, opossums, and others are all on the lookout for winter shelter. The deck or patio becomes a popular hangout for these critters, sometimes for the long run. Skunks can cause an odor problem, not to mention the damage and mess of digging. The solution is to exclude them, thus preventing access in the first place. This can be done by adding a fence below the deck, using 1/2 inch mesh hardware cloth, attaching it firmly to the deck frame and burying it 10-12 inches below ground.
Fall is also a common time when your dog or cat, if left to wander at night, may bring home the odiferous perfume of a “not-so-romantic” encounter with a skunk. What to do? The commonly suggested bath in tomato juice fails to adequately do the job and usually just make us or pets smell like tomatoes and skunk! If you, your pet, or side of your house is ever sprayed by a skunk, there is a very effective home remedy that works on almost all surfaces. The ingredients are inexpensive and commonly found around the house.
In an open container, mix together ¼ cup baking soda, a fresh 1 quart bottle of 3 percent hydrogen peroxide, and 1-2 teaspoons of liquid dish detergent. This solution must be used right away and cannot be stored. For pets and people, thoroughly work the mixture into the fur, hair, or skin, avoiding the eyes and mouth, and leave on for 5 minutes. Then rinse with fresh water and repeat if necessary.
This should eliminate the order, but avoid getting it on cloths that you don’t want bleached. Well laundered and deodorized clothing will, over time and exposure to air, lose the odor, although the garbage may be their ultimate fate way before then!
Skunks may get a bad rap for the smell, but remember to appreciate their striking pattern of black and white and their ecological role as consumers of our insect pests. And keep the hydrogen peroxide handy, just in case!
Photo Credits: Skunk damage, Iowa State University Extension and Outreach; Deck fencing exclusion, Jim Pease Iowa State University
Perhaps nothing is as frustrating to a gardener as losing their hard work and crop to unwelcome wildlife. After working hard all spring to get plants and seeds into the ground, fighting the weather, and conquering the weeds, just when the harvest is to begin some other vertebrate critters begin to harvest the plants. Rabbits, ground squirrels, tree squirrels, pocket gophers, or deer arrive to take advantage of the plantings you have provided--assuming you provided food just for them!
The two major defenses gardeners have against such competition are: repellents and exclusion. Repellents are either area repellents or taste repellents. Area repellents repel the animal by smell. As the name implies, the chemical is aromatic and fills the air in the general area of the planting. The smell is offensive to the animal and it avoids the area. Examples of such repellents include hanging bags of human hair or bars of soap or commercial products like moth balls (naphthalene).
Taste repellents are more effective in that they are applied directly to the plant and repel the animal by having a bad taste. The idea is that the animal may sample the plant once, but the bad taste keeps it from trying it again. Examples include such "home remedies" as cayenne pepper and commercial products containing such chemicals as thiram, putrescent egg solids, or other foul-tasting products.
Repellents are not, however, a cure-all. Area repellents are limited in effectiveness, but may be useful if placed around the perimeter of the garden area. Taste repellents cannot be applied to plants you intend to eat since you would also find the taste offensive, and thus are mostly useful in landscaping. Most repellents must be reapplied regularly, especially after rain or periods of extreme heat. Not all products are registered for or effective against all species. And, if an animal is hungry enough, they will often ignore the bad smell or taste. Despite these limitations, many gardeners may find repellents to be the best alternative in their particular circumstance.
Another more permanent protection against unwanted sampling of your garden is exclusion. You may exclude in several ways, depending upon the area you are in and the situation. Individual plants may be surrounded by plastic tubes, chicken wire, or hardware cloth fences. You may also fence off your whole garden area to exclude the worst offenders – rabbits and deer.
The size and mesh of the fence depend upon what you are trying to exclude. For rabbits, 1-inch mesh "chicken-wire" fence at least 2 feet high will successfully exclude them, especially if the bottom 2-3 inches are buried below ground level. For deer, you may use a variety of fences including electrical tape or strong large mesh of any kind. Old "hog wire" fencing filling many farm gullies will suffice, especially if several sections are erected, reaching a height of 8 feet. In small garden plots, you may be successful with fences somewhat shorter than that, but no lower than 5-6 feet.
Gardeners may find also that general clean-up of garden areas to eliminate the brush, log, or junk piles that provide protective cover for many of the offending critters will help. Also, the presence of pet dogs will often serve as an aversion to these wildlife.
Above all, keep in mind that a reality of gardening is dealing with pests and factors out of your control like weather. Gardens inevitably attract both those critters you want and those you don't. Some damage should be expected. When your tolerance level for such damage cannot be raised any higher try some of these repellent or exclusion methods.
The coming of every fall often also brings with it something else: mice! Two species of mice native to Iowa are seasonal visitors to homes in which they can gain access. 
The deer mouse and white-footed mouse make their way into homes in search of winter shelter after having spent the spring and summer outdoors raising young and foraging. The aptly named house mouse on the other hand, will live year-round in your home without the seasonal migration. Requiring enough space to fit their head through, about ¼ inch or larger, both outdoor species will bring in nesting material or create their own inside, chewing apart paper, insulation, foam and any other material deemed suitable for a cozy nest. These mice also begin stashing food, such as corn kernels and bird seed, which they survive on for portions of the winter.
Exclusion is the preferred method of avoiding the seasonal visits of deer mice and white-footed mice. Look for gaps in siding where the siding meets the foundation or where pipes and other utilities enter. Cracks in foundations and loose-fitting doors without proper weather stripping are other obvious places where mice can get in. And, because mice are good climbers, don’t forget to check for poorly-fitted windows and disrepair around the roof, including attic vents. Mice can easily travel within walls, and without a way into the living quarters, you may never notice them. Repairs to exterior openings are necessary to avoid costly damage to wiring and other fixtures of your house. Rodent-proofing can be as simple as adding or replacing weather stripping on doors and windows, which will reduce your heating costs, to filling cracks and holes with an expanding foam sealant. Because mice are chewers, it is recommended to tightly pack steel wool into the gaps first, and then apply the foam. Metal flashing will also create a chew-resistant barrier over openings. Other kinds of repairs may be necessary, depending on the location.
Trapping is necessary to remove mice already inside. Several varieties of traps are available, including the snap trap and the box trap. The snap trap, such as the Victor® EasySet, is a kill trap and can be baited with peanut butter or moistened rolled oats. Mice travel along the edges of and behind objects, taking advantage of the protection and cover this provides. Set traps against walls, along likely travel routes, and behind objects where you have seen or suspect mice. Their droppings provide a clue to where they have been. You can improve your chances of catching mice by setting multiple traps in different locations. Consider setting two together with the bait sides opposite each other. The box trap is a live trap, which includes the Victor® Live Catch and the Victor® Tin Cat Repeating Mouse Trap. The latter is ideal if you have more than one mouse in the house. This trap has two chambers, one where the mouse enters and one where the mouse goes when it is caught. The trap is designed to automatically reset itself so that multiple mice can be caught at once. The trap works without bait and relies on the natural curiosity of mice. Again, these traps should also be set against walls and along likely travel routes. Mice can be released outside, but complete repairs so these same mice do not return.
Keep in mind this additional information. First, properly store grains and other seeds in rodent-proof metal containers and avoid leaving food out overnight. We do not recommend poisons as an initial solution unless all other methods have been unsuccessful. Use of poisons can be a risk to pets and children and often means mice die in inaccessible places, which can cause order problems. Also, glue traps, while effective at catching mice, are also not recommended, as this is generally messier and subjects the mice to a slow death due to starvation and injury. Finally, ultrasonic devises labeled as rodent repellants do not live up to company claims and independent research has not shown they are effective at rodent control.
Photo Credit: White-footed mouse, D. Gordon Robertson, https://commons.wikimedia.org/wiki/Main_Page Mouse entry hole, http://ICWDM.org
Reference to brand names should not be taken as an endorsement but rather is used to illustrate available methods.
Bats are extremely valuable in insect control and a welcome and often misunderstood part of Iowa's natural environment. We want them flying around outside gobbling mosquitoes, crop-damaging insects, and others. We just don't want to share their living space with them! Click here to learn more about Iowa's bats and the challenges they face.
Like almost all other animal species, Iowa law protects bats. While homeowners are allowed to protect their property, repellents are largely ineffective, including those expensive "sonic" or "ultrasonic" devices and the relatively inexpensive mothballs. Thus, excluding bats from buildings is the only way to deal with them. Understanding some bat habits is the key to successful exclusion.
First, bats are nocturnal. They emerge from their roosts at dusk each evening, searching for food and water. Thus, exclusion activities must be done after they've emerged, NOT during the daytime. Blocking entrances during the day only guarantees more severe problems, increasing the likelihood that they will come down through the walls in search of a way out or die in the house, causing a different set of problems for the homeowner.
Second, bats follow air currents. Any spaces--say, your attic and a bedroom--that have different temperatures and are connected by a crack or hole, automatically have airflow between them. Bats simply follow those air currents. Blocking those air currents is the key to successful bat exclusion.
Third, August and September are the best time to do the exclusion. Bats are mammals and often form maternal colonies, a mother and her one or two young hanging together with dozens of other mothers and young. Since young bats are naked and blind, mothers leave them behind each night to seek food and water, returning later in the night to nurse. If exclusion is done prior to August you may only exclude the mothers and end up having the young die in your house.
Finally, only two of Iowa's nine bat species, the big brown bat and little brown bat, commonly use buildings in the summer for colonies. Only the big brown bat uses buildings in winter. It is mainly these two species that cause problems for homeowners.
Wait until after August 1st to exclude bats to ensure flightless young are not orphaned inside the home.
Finding the entrance can be a family affair. Take lawn chairs, your favorite drinks, and a flashlight and sit outside in your yard about sundown. Watch for emerging bats. Check the obvious places first: around the chimney, gable vents, or roof vents. Don't forget the not-so-obvious places also: under the eaves, behind the rain guttering, under torn shingles. All these are common entrance sites and indicate that some repair is in order. Some buildings have more than one entrance site. Any holes the size of your thumb or larger are enough for bats to find and exploit. Don't forget, many bats may use the outside of your house without posing any issues to the inside, so be sure to find likely entry points, as illustrated in this figure.
Once you've identified the entry points around your home build a one way door on the outside of the house to allow the bats to crawl out of the hole, but not fly back in. A one-way door will be anchored above the hole and then hang loosely below. It can be made from half-inch mesh bird netting, screen wire, heavy cloth, or even a sock with the end cut off to create a tube around the hole.
Let's say, for example, the entrance is a crack one half inch wide and 6 inches long. Cut a piece of netting or screen. Place it over the entrance crack so that the entrance is in the upper half of the net/screen. Use duct tape to tape the top and two sides of the screen to the building, leaving the bottom edge open and just loose enough for the bats to squeeze out. Bats will emerge that evening, hit the screen, crawl around until they find the bottom loose, and then fly out. When they return, they return to where the air current is--the crack--not to the bottom of the screen. If you leave this up for 4-7 days, you can be assured that all bats are out and the repairs can be made, this time during the daylight hours.
Use foam sealants, fine (half inch or less) wire mesh, new boards or soffit, plaster, or any other means necessary to fill all holes in and around your home to prevent bats from finding their way in again.
For more detailed information on issues with bats around the home visit the detailed article on bats from the Prevention and Control of Wildlife Damage manual.
The eastern cottontail rabbit (Sylvilagus floridanus) and the white-tailed jackrabbit (Sylvilagus townsendii) are both found in Iowa. The eastern cottontail is far more common, as white-tailed jackrabbit populations have declined considerably in abundance and distribution. Rabbits have large incisor teeth which they can use to cause damage to flower and vegetable gardens, as well as trees and shrubs. This page will focus on cottontail rabbits since they are much more common and are more likely to be a source of damage in Iowa. There are several methods for preventing and reducing damage caused by cottontail rabbits.
Habitat: Cottontail rabbits like brushy areas and landscaped backyards. As long as sufficient food and cover are available, rabbits can spend their entire lives within a few acres or even within the same backyard. Cottontail rabbits don’t dig burrows. In the summer they use plant growth for cover. In the spring and fall when plant growth is sparse they will dig a small nest at the surface of the ground to decrease their visibility to predators.
Reproduction: Mother cottontails dig small nests in the ground for their young. They line the nest with fur and also cover their young with fur to help protect them. Cottontail rabbits are prolific in their production of offspring and can have up to six litters per year with each litter having up to 6 babies.
Damage: Cottontail rabbits have a broad plant-based diet which means they can cause damage in multiple areas and seasons. They will eat flowers as well as fruits and vegetables. Rabbits will also chew on woody plants and remove bark from trees and saplings to get to the nutritious cambium between the bark and the wood. Teeth marks are often visible upon close inspection of damaged woody stems.
Damage Control and Prevention: As with most nuisance wildlife, exclusion is the best way to prevent rabbits from causing damage to certain plants. To exclude rabbits, consider the following options or steps:
Efforts to make your yard less appealing to rabbits can help reduce their impacts. Removing brush piles, reducing thick patches of grasses and flowers, or eliminating other features such as piles of stone that may provide cover for rabbits can deter them from spending time in your yard. Fencing off spaces under decks and buildings also removes these as shelter options for rabbits.
If direct exclusion practices are not effective in addressing your rabbit issues, consider methods to reduce their populations. Hunting is permitted for eastern cottontails state wide during specific season and with specific licenses. Hunting can reduce the population of rabbits on a farm, but is not effective in small yards or cities.
Many vendors and gardeners suggest a wide range of possible deterrents to scare or dissuade rabbits also. Methods that involve scaring rabbits away include scarecrows that spray water, lifelike recreations of common rabbit predators such as owls and snakes, glass jars filled with water, and shiny spinning objects. These tactics will only provide limited results and are only effective within a close proximity. Rabbits will also become used to them over time. Commercially available or home-made taste repellents can be used on plants that are not meant for human consumption. Usually these make the plants taste or smell bad to the rabbits. However, these usually wear off especially when the area is watered or rained on so they must be re-applied regularly.
This article is an update of "Rabbit damage to tree plantings" (WL-47) originally authored by Robert B. Moorman and Reinee R. Eshelman and reviewed by James Pease.
In the fall and winter, groups of wild turkeys are easily spotted in fields, giving the impression that they may also be wandering there during the growing season and causing damage. However, in the spring and summer wild turkeys are much more likely to be eating insects and leftover grain from the previous year than actually having any effect on crops. If damage is discovered in a field it is more often caused by less conspicuous culprits such as night time visitors like deer and raccoons or smaller mammals that go unseen. Even in hay and oat fields where the wild turkey’s large size can be attributed to knocking plants over, damage caused by wind, rain, or water can occasionally be misattributed to the trampling of turkeys.
History: By the early 1900s settlers in Iowa had wiped out wild turkey populations through unregulated harvest and habitat destruction. There were multiple attempts to reintroduce wild turkeys to Iowa but none were successful until the 1970s when wild turkey numbers increased enough for a spring hunting season to be available. By the 1980s both spring and fall hunting seasons were available. Since then, wild turkeys have provided great hunting and viewing opportunities throughout Iowa.
Breeding Behavior: During spring breeding season males can be seen displaying their impressive tail fans and heard uttering their iconic gobble calls. Females lay their eggs on the ground in the woods near bushes or brush that provide cover. Turkeys stay in small groups after the breeding season. In the fall the young males form their own flocks. During the winter multiple flocks congregate together and typically feed on waste grain in fields. These large flocks break up into smaller groups again in the spring when food is more readily available across the landscape.
Habitat: In Iowa, turkeys prefer habitat that includes a mixture of wooded and open areas like fields. They utilize woods primarily for nesting and roosting but will search for food in these areas as well. Open areas near woodlands are also utilized for foraging.
Diet: As wild turkey numbers increased in Iowa, some people worried about the effects they would have on crops. Multiple studies have been conducted to learn what wild turkeys eat. These studies have found that wild turkeys rarely, if ever, dine on standing crops. Wild turkeys have a small pouch in their neck called a crop that holds food before it is digested. A study in southwest Wisconsin examined the crops of over 100 wild turkeys and found that over 50% of the turkeys’ diet was waste corn, which was easily distinguished from kernels of growing crops by its dirty and worn appearance. They also found that wild plants made up 27% of the turkeys’ diet. Insects are also an important part of all turkeys' diets, but they made up a much larger portion (77%) of the diet of young turkeys who need protein to support their growth. In Iowa the Department of Natural Resources and Iowa State University conducted a study where they watched turkeys eating in fields. During this study turkeys were never observed digging up crop seeds or seedlings. Instead the turkeys mostly just looked and consumed insects on and near plants. The researchers did find that if another animal, like a raccoon, knocked down corn stalks the turkeys would feed on the corn that was then available on the ground.
Damage Identification As described above, multiple studies have found that the primary food sources for wild turkeys in Iowa are wild plants, insects, and waste grain, rather than standing crops. It is more likely that any damage identified in a field was caused by other wildlife.
If you do have damage in your fields and want to know which wildlife are causing problems check out our Wildlife Crop Depredation page, the guide Identification of Wildlife Crop Depredation produced by Purdue University, and the Iowa DNR article on identifying crop damage. The Iowa DNR also has a Wildlife Damage Management page with other resources, including a Wild Turkey and Crops brochure.
This article is an update of "Managing Iowa Wildlife: Wild Turkeys" (PM 1302f) by Steven Gabrey, Paul Vohs, and James Pease
With their colorful plumage, quirky habits, and a propensity to attend backyard feeders, woodpeckers are among the most well-known and popular birds in Iowa. Unfortunately, their habit of drumming on wood siding and metal gutters sometimes gets them into trouble. Fortunately, with proper construction techniques and building materials, we can limit the damage that they might cause.
In Iowa, there are seven woodpecker species, all of which dwell around human habitation at various times of year. The downy woodpecker, hairy woodpecker, and red-bellied woodpecker are resident woodland birds that have adapted to living in wooded towns, farms, and cities, where they frequently visit feeders. The strikingly patterned red-headed woodpecker prefers open woodlands and farmlands with scattered trees, especially in areas with abundant mast-producing trees (oaks and hickories); it stops by residential areas largely during spring and fall migration. Likewise, the northern flicker likes open ground to search for ants and other invertebrates during warmer months. However, in fall and winter, the flicker incorporates a variety of wild berries into its diet; other woodpeckers also make this dietary shift, albeit to a much lesser extent.
The crow-sized pileated woodpecker principally inhabits large tracts of mature forest with numerous dead or dying trees, on which it creates large, square-shaped drillings in search of insects. Although secretive and less common than other Iowa woodpeckers, this vociferous giant occasionally finds its way into urban/suburban neighborhoods bordering parks and greenbelts, as well as wooded farmsteads that have extensive forests nearby. Finally, the yellow-bellied sapsucker, which nests in aspen woods in the northern third of the state and silver maple floodplains in the northern half, spreads out to visit towns, parks, orchards, and farm groves across Iowa during migration and winter.
The following tendencies make woodpeckers prone to causing property damage at times.
Keep in mind that even the best deterrents fall short of stopping all woodpecker damage. These techniques merely reduce the problem, with varying levels of success. Below, we have listed some of the available remedies from most to least effective, approximately, based on current research.
More Effective
Less Effective
Selecting the right materials when designing a house is by far the foremost means of curtailing woodpecker damage. If the external elements do not appeal to woodpeckers for drumming or feeding, then they are less likely to damage a building. But if you choose materials that make great drumming platforms or harbor tasty insects, then you’re inviting a perpetual battle.
Construction materials on exterior of houses and other buildings
Avoid: wood shakes, grooved plywood, tongue-and-groove, and board-and-batten sidings
Use: clapboards and modern non-wood sidings whenever feasible.
Sealants/paint on exterior of houses and other buildings
Do not: use stain sealants, especially earth tones, as these colors attract woodpeckers.
Do: protect existing wood siding with paint rather than reapplying stain sealant.
Sapsuckers occasionally injure trees by drilling numerous “sapsucker wells”, rings of holes from which the birds feed on sap and insects trapped in the sap. These holes sometimes serve as entry points for infections in the trees. If you have a persistent issue of sapsuckers on your valuable trees, consider some of these possible remedies.
Keep in mind: The Migratory Bird Treaty Act protects all woodpeckers as native, migratory, non-game birds. It is illegal to kill or harm them. The U. S. Fish and Wildlife Service issues permits for lethal control only in extreme circumstances. Thus, prevention and exclusion are keys to limiting the potential impacts of woodpeckers.
This article is an update of "Managing Iowa Wildlife: Woodpeckers" (PM-1302c) originally authored by Steven Gabrey and James Pease.
Although not as notorious in Iowa yards as moles, the plains pocket gopher (Geomys bursarius) can be an unwelcome guest in lawns and fields across most of Iowa, generally becoming less common in the eastern quarter of the state. It is an expert burrower, and its habit of creating dirt mounds and vigorously tunneling through soil on occasion leads to conflicts with property owners, including impairment of drainage tiles and underground utility lines, weakening of embankments along ditches and dikes, damage to mowing equipment, and diminishing the general aesthetics of lawns and other manicured areas. Pocket gophers can clip and girdle the bark of trees and shrubs and can consume the underground and aboveground portions of various garden, commercial, and ornamental plants.
Pocket gophers are a species of conservation concern in Iowa because the loss of Iowa's native grasslands and farm pastures has reduced the amount of habitat for them throughout the state. Therefore, caution should be taken in the control of their populations, and only efforts to reduce or dissuade their presence on your farm should be considered if they are doing economically consequential harm.
Habitat: The plains pocket gopher occupies open, grassy areas, such as prairies, meadows, pastures, hayfields, lawns, cemeteries, golf courses, and sports fields. Generally, pocket gophers are more likely to colonize locations surrounded by extensive grassland. However, the presence of ditches, fencerows, field borders, and other grassy corridors can enable pocket gophers to survive within stretches that would otherwise be uninhabitable. In any setting, soil composition is key: pocket gophers reach their highest densities (6 to 8 gophers per acre) in sites with porous, well-drained, loamy soil. Excessively rocky soils present too many obstacles for burrowing, while shallow or extremely sandy soils are not stout enough for tunnel walls to stay in place. Furthermore, because pocket gophers seal their tunnels off from the surface, they must breathe air that circulates through the surrounding soil. Thus, soils that are excessively compacted, like those with clay or heavy moisture, do not allow for enough air to cycle in and out of the tunnel.
General biology: From a small, compressed head connected to a short, thick neck, to muscular forelimbs armed with long, curved claws, and short hind feet tipped with shorter, straighter claws, nearly every aspect of a pocket gopher’s stocky anatomy makes it a burrowing machine. The extensive tunnels that a pocket gopher creates dominate every aspect of its life cycle – from feeding to sleeping to reproduction. Except when mating or raising offspring, the plains pocket gopher remains solitary. An individual will create and maintain its own tunnel system, although multiple tunnel systems (and therefore multiple gophers) can be present in the same lawn or section of field. As would be expected by their burrowing nature, pocket gophers spend most of their time underground. However, they venture to the surface to feed within close vicinity of their tunnel entrances.
Plains pocket gophers reach breeding age at the end of their first year. After a gestation period of about three weeks, females give birth to a single litter of 3-4 young (sometimes up to ten) some time from April-June. Males may share the female’s burrow for a few weeks to help care for the young before moving on to another burrow. After weaned from the mother, the young disperse outward to establish a new burrow; this often entails a dangerous trek across the surface. Pocket gophers of all ages fall victim to a variety of predators, but they are especially vulnerable to badgers, which are proficient at digging them out of their tunnels. Weasels and snakes (especially bullsnakes) capture pocket gophers within their tunnels; skunks, raccoons, foxes, coyotes, bobcats, domestic dogs, cats, hawks, and owls are among the many animals that dine on pocket gophers that venture onto the surface.
Diet: Unlike moles, which prey on invertebrates, the plains pocket gopher is strictly an herbivore, using its long, sharp teeth to gather grasses (like bluegrass in lawns) and broad-leaved plants (most notably alfalfa), as well as bark and stems of trees and shrubs. During warmer months, pocket gophers frequently consume roots and bulbs that they encounter while digging and eating additional portions of plants they pull down into their tunnel. They also make brief excursions onto the surface, where they extend out as much as a body length from their tunnel to feed on neighboring plants, including the bark of trees in lawns and orchards. During these aboveground forays, especially during winter, they often clip the stems of young trees and shrubs.
Damage identification: Although tunneling can occur at just about any time of year, spring and fall are prime seasons. A single pocket gopher is capable of establishing a long series of tunnels (up to 200 yards per individual) and mounds made in quick succession (1 to 3 per day, leading to as many as 70 in a month or 200 in a year). The poorer the soil and food base, the longer the tunnel system needs to be to support a pocket gophers life cycle. However, high-quality habitats lead to higher densities of gophers, even if the individual tunnels are less extensive and the mounds less numerous. In any case, look for the following distinctive signs of pocket gophers:
Large, crescent or fan-shaped dirt mounds. Gopher mounds differ considerably from the conical (volcano-shaped) mounds made by moles.
Extensive network of underground tunnels that are NOT visible from the surface
In addition to considering the tunnels and mounds excavated by moles, one should also make sure to rule out the narrow, surface-level pathways that meadow voles make when moving among their golf ball-sized burrows in lawns, pastures, golf courses, and other grassy habitats.
In instances where pocket gophers become especially troublesome, trapping of individuals to remove them from the area can be an effective way to address damage. The first key is to find the main tunnel, which is usually located 12-18 inches away from the plug on the crescent-shaped mound. Once you have found the main tunnel, you can then place traps in the secondary tunnels, which run laterally off the main tunnel.
Locating the best place to trap or bait gophers:
Trapping to eliminate gophers: Although not particularly feasible across broad expanses like hayfields or golf course, trapping is a proven means of removing problematic pocket gophers from smaller patches, such as lawns and ditch embankments. Multiple trap styles exist, including Macabee gopher trap, Death Klutch 1 gopher and mole trap, and Victor Gopher-Getter, as well as various homemade traps.
This article is an update of "Managing Iowa Wildlife: Pocket Gophers" (PM-1302a) originally authored and edited by Jason O'Brien, James Pease, and Kurt Johnson.
