A comprehensive strategy for wild pig control

Introduction:

The proliferation of the wild pig has become of serious concern to a variety of professionals.  From wildlife biologists throughout the nation to the concerned hunter, the agriculturalist and the simple nature-lover, the rampant spread of the wild pig has been wondered at and argued over for several years.  Regardless of the origin of the animal or the nature of its proliferation, an effective and comprehensive methodology is needed to address this issue.  A wide variety of methods have been used with varying degrees of effect.  Although some methods have successfully controlled populations, the desired effect came after a long, arduous, and expensive journey.  With recent advances in technology one can gain control of a local population in a more time efficient manner.  I hope to show how one might control a population in a relatively rapid fashion but ultimately, the will and desires of the individual paying the bill will dictate the animals’ penetration level. 

The specific area concerned with this research is the bend of the Tennessee River, just west of Florence, Alabama.  Research was conducted across the property lines of several entities.  Crossing property lines is no small part of this equation.  Quite often, what one individual does on his land varies dramatically from his neighbor.  This often leads to difficulties in controlling wild pigs.  The argument is most often between agricultural interests and hunters although public land is also often adversely affected.   Different strategies attempted include predominantly trapping and sport hunting strategies.  Individually, few of these strategies had a significant effect.  Used together, progressive hunting and trapping can be very effective. The benefits of effective control are immense and readily apparent to virtually everyone involved.  However, the effort to gain control of a mature population must be broad if positive control is to be achieved.    Eradication will only be possible with access to all of the land involved and active support from the inhabitants.

Hunters and agricultural interests do not always contrast; in fact, several efforts have been made to use sport hunting as a control methodology.  Initially, this would seem a logical and excellent way to address the issue.  Unfortunately, hunting tactics and population control tactics are very dissimilar.  Average hunters across the United States have neither the equipment nor the knowledge to address this issue effectively.  Simply put, the nature of the wild pig requires that the hunter often operate at night.  Most types of night hunting are restricted dramatically in comparison to daytime hunting for a variety of reasons.  In order to safely hunt at night one must be intimately familiar with the terrain and be an experienced shooter.  Often, people unused to working at night or in low-light conditions have difficulty orienting themselves visually.  This common occurrence is obviously unacceptable for individuals handling firearms at night.  Aside from the obvious safety concerns, an experienced shooter is required to make multiple successful rapid fire shots.  This combination of skills is difficult to attain.  One usually does so either in an elite military or law enforcement unit.  Unfortunately, these individuals are relatively few and generally involved in a professional capacity.  The use of hunting tactics can have a dramatic effect on the overall population but must be very proactive.  Hunts must also be planned in detail and contain sufficient training for essential safety concerns.

In creating a GIS model for this application, quite likely, information gathered from internet sources is insufficient.  Details about the structural condition of roads and accessibility to specific low terrain features are often not indicated in these sources.  Much of the specific information required to control the species will be unavailable in electronic form because wild pigs exist in a form of “blank space” in our society.  In virtually every account absorbed, individuals working on the issue state that the natural habitat of the wild pig is low, dense, and wet.  Few people venture into the wetland regions that surround them.   The bend of the Tennessee River is no different, rather than a concrete thoroughfare with multitudes of people, one might encounter one or two people in a day outing.  While traveling along pig corridors, one would never know human society existed.  Controllers, that is, those attempting control methodologies, must work in a habitat highly uncomfortable for humans.  The wild pig has no such difficulty. 

Identifying primary travel corridors using GIS is very simple.  If you have a wild pig problem or think you might, go to the ugliest swamp on your property and look for sign.  Scientifically, find dense vegetation that extends from depressed terrain to a predominant seasonal pull factor (i.e. nearest cornfield etc.) and likely, that is the primary travel corridor.

The nature of the animal prohibits extensive geographic analysis in some aspects because it does not behave in a manner that is consistent with other, more familiar animals.  Many game animals have somewhat established patterns of daily movement.  While wild pigs establish places that they visit repeatedly, they do not generally travel there in an established pattern.  Rather, upon departure from the bedding area, their general path may be completely random, but will hit several established locations en route.    

One of the most effective methods of control is trapping.  While certainly not a new technique, in many ways it is dead or dying technology.  Today’s trappers are few and far between.  Often, individuals attempting to trap wild pigs do not understand specifics of the animal or the nature of trapping.  One of the traps observed during research had been deemed largely ineffective.  It had initially been successful but only for a few animals.  Quite possibly for ease of mobility, the trap had been placed in the corner of a pasture, on the edge of the tree line.  Trap placement was the crucial missed decision.  In placing the trap here, the controller put it in competition with natural forage.  Upon arrival at the open feeding area, the animal had no desire to enter a very foreign object and to potentially compete with a raccoon for possession of the contents.  Light humor aside, trapping techniques utilized must be informed and continuously updated.  One basic rule of trapping is that one should try to target specific animals.  As applied to wild pigs, there are three basic trap designs that should comprehensively address the issue.   These trap designs were selected based on the average size of traveling groups and this control methodology.

The “Nature of the Beast”

            The wild pig has proven to be a worthy opponent to control methods for a variety of reasons.  Its inherent nature and associations make it difficult to address.  That being said, they also provide the keys to effective control.  Predominantly, the animal associates to low lying terrain and extremely dense cover.  While this seems to be simply a statement of the obvious, the problems associated with it have dramatic effects.  Often, few if any people go into these regions during a normal day and few vehicles are equipped to master this terrain.  These associations and the difficulties involved in addressing them, often preclude effective controls.  

The basis for this control methodology is in the movement patterns of the animal.  Like most animals, spatial parameters of movement are predominantly effected by age.  When newborn, wild pigs stay primarily in the bedding area.  The bedding area is often in extreme terrain for humans.  Several sources indicated that when finding bedding areas, if one wasn’t crawling through a swamp on hands and knees, then they had not gotten close to the bedding area.  For piglets, this is the Hilton, complete with room service.  Throughout the first several weeks of life, piglets have no need to leave the bedding area.  Exposure of piglets to regions providing adequate human access for control often does not occur for several weeks.  This age and proximity transition provides the best opportunity to implement controls.  When the piglet does leave the bedding area, it does so with one or more protective sows and travels to primary feeding areas.  These movements are of relatively large scale often involving a significant portion of the sounder.  Large volume traps should be placed along the corridor between the bedding area and the primary (seasonal) food source.

Adolescent and adult pigs are not as spatially limited.  During this time wild pigs often forage in small groups of three to four animals.  They also begin to roam on a much larger scale and have a variety of secondary pull factors that influence their movement.  In this area of study, the dominant secondary pull factors were long needle pines, clay soils, cedar trees, and open pasture.  There are many different items that fall in the category of secondary pull factors.  These factors are dependent upon regional ecology and the season.  Long needle pine and clay soil are very common throughout this vicinity.  The long needle pine has rough bark and is popular with the animal for comfort (rubbing) and insect control.  Clay soils are preferred for wallows which provide thermoregulation.  These specific pull factors, though used year round, are more dominant during the warmer portion of the year due to thermoregulation. 

Cedar trees also seem to effect movement.  In the bottomland south of the bedding area, a number of cedar trees are indicated.  The grass and shrub between each of these is crisscrossed with trails.  Most individual trees have several trails connecting them.  While the main route of travel through the vicinity is covered in pig tracks, each of these trees has little or no sign leading specifically there and virtually no sign of activity around the tree itself.  This indicates a seasonal pattern.  While obviously the animal had readily associated with the trees in the past, it was currently not doing so.  While unable to specifically cite this pull factor, logic indicates that warmer seasons with attached insects would lead this specific animal to shade and relief.

Pasture areas also provide a significant secondary and seasonal pull factor.  Wild pigs are often accused of eating the manure of other animals.  While some of this material may be consumed by the wild pig, the forage sought after is the small green shoots of new growth found beneath.  While this food is likely desirable year round, it will be stronger when other sources are less prominent.  During the latter portions of winter, when acorns become increasingly rare, pigs will inherently venture into more open terrain in seek of forage. 

Secondary pull factors can be widely diverse.  Telephone poles and railroad ties are just two of many things that can be secondary pull factors.  For control purposes this is one of the more difficult problems.  To implement control methods effectively, one must know which of these pull factors is most active for both the season and the region.

High Volume Trapping:

The first trap design is the high volume fence trap.  Ideally, the trap is simple stockyard panels of heavy gauge fence material.  The fence panels are securely erected in a large teardrop shape.  The door can be configured differently dependent upon the user but must allow two or three animals to enter simultaneously.  Usually the trap is baited without being set for a few weeks to establish a pattern of entry.  This will allow the controller to trap a large group at once. 

The targeted group for this trap is the sounder itself.  As siblings age, they often venture from the bedding area in a large group.  Usually accompanied by one or more sows, these groups tend to more densely covered regions.  High volume traps should by placed approximately midway between the bedding area and the primary seasonal pull factor while still remaining in extremely dense micro terrain.  If possible, they should be placed under a mast producing oak tree.  The trap must be of large enough space that an entire sounder will fit inside.  A combination of camouflage and shade are required to deceive and then protect the animal until removal.  The trap must also be accessible by a vehicle that can extract a large number of animals.  Removal of these groups whenever possible, will have a dramatic impact on overall group size and proliferation rate.  In the wild, most pigs have only one (sometimes two) litter per year.  If a consistent entry pattern can be established, one might postulate that the trap could be “set” annually for a short period of time, and thus control the population.  Despite theory, this large volume strategy is known to work in trapping large groups at once.  A significant upgrade to this type of trap would be to add technology.  Current technology would allow the controller to both view and trigger this or any trap remotely.  With these assets a controller could reduce wait time considerably.  Rather than prebait two to three weeks, a controller with modern assets can erect and set his trap immediately, then monitor and trigger it remotely when the targeted animals are in place.  The high volume fence trap is highly effective when erected and utilized correctly.

Low Volume Trapping:

The second trap design is much smaller.  The basis for size selection was drawn from the average sized traveling group of juveniles or adults.  Often foraging groups will be only three or four animals.  These groups forage significantly farther from the bedding area and on higher ground.  Traps directed at these groups should be placed in heavy micro terrain, either between the bedding area and secondary pull factor or the main travel corridor and secondary pull factor.  Cage traps should be well camouflaged and baited more specifically.  Traps accommodating four animals are of small enough design, that they can be camouflaged with relative ease.  In effect, camouflage makes traps appear much less intrusive and wild pigs much more likely to enter.

            Door design and baiting methodology are primary concerns.  Ideally, one cage size can be fitted with a variety of doors or trigger mechanisms depending upon application.  If a controller needs to address a large number of average sized animals over a broad region, simple corn baiting with multiple entry door design will be effective.  However, if educated and solitary boars are targeted, a large drop gate combined with prolific “sweet” baiting may be required.  “Sweet” baiting differs from normal baiting in that wild pigs will go significantly farther to get some foods than others.  In one instance, pigs travelled several miles to get sorghum from a trap, bypassing several other forage opportunities.

            GIS can indicate the general vicinity for trap placement, but the controller must decide several things.  He must establish, specific placement with concern for camouflage, door design, trigger design and baiting methodology.  An often overlooked concern for trap design is the sensitivity of the wild pig foot.  Often, wild pigs will balk at entering cage trap designs, because of the flooring.  Whether it is simply uncomfortable or unfamiliar, wild pigs often will not enter a trap with a panel floor. 

            Cage traps provide a versatile tool for the feral pig controller.  If placement is preconceived one can adjust it to address a variety of circumstances.  Self-contained, the trap can be simply loaded on a small trailer and dropped quickly in an ideal location.  This is often easier said than done.  Traps of this size are very heavy and movement from the trailer to the ground may be extremely difficult.  Another complication is ground consistency.  Any vehicle used to insert or extract traps must be very robust, have four-wheel drive or locking hubs and be small due to the dense nature of habitat.               

Hunting Strategy:

            Many sport hunters feel that they provide the best natural answer to this problem.  Hunting can be a very effective means of wild pig control but most hunters are not properly equipped or experienced to address the specific needs of wild pig population control.  Traditionally, hunting at night has been very limited simply due to lack of visibility.  Modern technology now exists that can make a hunter extremely effective at night.  Unfortunately, night vision, forward looking infrared (FLIR) and thermal technology is generally outside the price range of the individual and is only used by various government and military interests.  Simply equipping civilians with this technology is a poor answer.  While the hunter can now see at night, there still exist a number of concerns for night hunting. 

Simply put, a successful control hunt ends with a number of pigs in the ground slowly becoming delectable barbeque.  In order to achieve this in a time efficient manner, progressive and modern hunting tactics must be used.  One or more experienced hunters must be in relative close proximity to as many pigs as possible with a weapon that allows them to see and shoot rapidly at night.  In order to be efficient they must have the correct tools and knowledge to address their task and do so in a safe manner.

            Two common weapons combined with modernized optics can address this need.  The first is a standard twelve gauge shotgun loaded with heavy buckshot or slugs.  Most effective at short ranges, the shotgun lends itself to tree stand or similar hunting tactics in dense vegetation.  In much of public perception buckshot has been deemed somewhat inhumane.  (Much of this is due to illegal poaching.  Targets are often at extreme shotgun range in this application.)  However, when used correctly, this is quite possibly the most effective means of instantaneous expiration.   Firearms technology has also begun to provide much more versatile shotgun ammunition in recent years.  Simple practical ballistics tests will readily indicate the proper load and aiming region for each weapon system. 

            Technology assets used in conjunction with the shotgun primarily consist of light and laser.  Mounting a powerful flashlight to a shotgun allows the user to see quickly and “aim” with a beam of light.  A laser attachment further enhances the overall effect.  When constructed and coordinated correctly, this design will allow the hunter to quickly comprehend the range to target based on the “footprint” of light, and the laser provides an aiming point.  In this manner, one hunter in a tree stand can engage multiple targets as they traverse beneath.  Again safety is the primary concern.  Hunters must maintain muzzle awareness and positive target acquisition.  A light on a weapon is a valuable tool but inexperienced users are often tempted to use this light as if a weapon were not attached.  This is a highly dangerous and potentially deadly habit.

            The second weapon system is a simple high powered rifle with advanced optics.  Like the shotgun, specific concerns and requirements must be addressed in rifle selection.  Although virtually any rifle in the proper hands will prove decisive, choosing the proper weapon will have significant advantages.  Ideally, the rifle selected is semi-automatic, large bore, and accurate to at least five hundred yards.  Chamber size and ammunition selection must be carefully considered.  Each round delivered downrange must have an immediately devastating effect on the targeted animal.  Experienced shooters are required to ensure positive shot placement for multiple rapid fire shots.

            Recent advances in technology further assist in this endeavor.  Forward looking Infrared, Night Vision, and Thermal imaging are all currently available in a form readily joined to various weapons.  This technology is predominantly used by law enforcement and military entities but its application to wild pigs can change control methodology dramatically.  When engaging multiple targets, an ideal situation is one in which the target contrasts with the background.  Forward looking infrared and thermal imaging systems successfully achieve this in dramatic fashion.  Targets, due primarily to heat signature, appear white-hot against a black background or vice versa.  The shooter, with the correct stand-off distance and from a rested position, can make highly accurate and rapid shots.  Another advantage to this technology is that it provides some level of foliage penetration.  The way animate objects contrast with inanimate objects in FLIR and thermal imaging, allows the user to observe better at night than day. 

 

Hunting Safety Concerns:

            Several inherent safety concerns emerge when operating firearms at night.  Some are more dangerous than others but all can be addressed through proper planning and the use of experienced shooters.  One of the primary concerns is simple land navigation.  Finding one’s way around a property can be complex when unfamiliar with the area.  Even experienced individuals can often become disoriented when traversing new terrain, even during daylight hours.  This is compounded several times when working at night.  Any level of disorientation is undesirable and potentially dangerous.  Furthermore, to be completely efficient, hunters must be able to coordinate shooting positions and their movement between them.  Ideally all shooting positions will be known to all shooters and safety can be assured through proper communication.

            A second concern is proper understanding and manipulation of imaging technology.  A proficient shooter must understand his equipment, its application, abilities and limitations.  He must also be able to properly manipulate both weapon and optics in low-light or no light conditions.  This concern is focused on both efficiency and safety.  If the shooter doesn’t have at least a basic understanding of the weapons systems, he will be much less effective.  If imaging technology is not properly used, targets may become difficult to identify.

            One of many simple techniques used to provide additional safety is the use of aiming stakes.  Often used in defensive military positions, aiming stakes define the lateral limits of the shooting position.  After shooting positions have been discussed and identified using GIS, each shooter will, upon entering a shooting position, thrust small sticks in the ground along a predetermined azimuth.  In this manner two or more shooters can address a target region without endangering other shooters.  They can also effectively address a wider range of targets. 

            The most important safety factor is the individual shooter.  Through a combination of experience and technology, each shooter must retain presence of mind to differentiate shoot situations from no-shoot situations.  There is no room in professional shooting for “buck fever”.

Snare Technology:

            Snaring, perhaps the oldest of trapping techniques, can be effectively implemented both individually and collectively with hunting strategies.  Although highly effective, this strategy requires that the user remain somewhat close to the trap and monitor it often.  The most effective manner in snare control methodology will be in conjunction with hunting strategy.  Coordinated fire on a group of wild pigs may effectively channel their egress into the nearest dense cover.  If a number of snares can be emplaced along the corresponding routes, individual animals can be trapped while running.  Used in this manner, the wild pig is not given the opportunity to develop fear or knowledge of the trap and can be taken on a much larger scale.  Another benefit to this method is the minimal time that the trap will be in place.  This limits the ever present danger that unintentional animals will be caught.

Conclusions:

            The behavior and spatial patterns of the wild pig make it difficult to control.  Because of its unpredictable and often nocturnal movement patterns, most normal control methods have limited effect. Broad implementation of modern technology can provide positive control of a significant population in a limited time.  With that in mind I propose the following methodology.     

            When presented with terrain.  The controller must first establish bedding areas, primary pull factors and the secondary micro terrain features that the wild pig is associating with.  The next step is to analyze these factors spatially using geographic information systems and determine proper trap placement.  Depending upon the size of the group, land available and various pull factors, traps will be placed appropriately.  During the course of this scouting, analysis, and erection phase, hunting positions can be discussed and analyzed.  Ideally, this phase will last less than one week.

            Large volume traps can be erected with remote monitoring and triggering mechanisms.  With this technology in place, prebaiting time can be significantly reduced.  If monitored efficiently, the large volume trap can be triggered the first time a significant number of animals are in place.  Low volume traps can be erected and set without electronic monitors.  Because of the nature of this trap and the animals targeted, electronic triggering will likely not achieve the desired result.  Rather, these traps will be triggered in the traditional manner and baited specifically to encourage multiple entries prior to apprehension.  All traps must be checked periodically and captured animals removed quickly and with discretion.  The intelligence of the wild pig is often underestimated; care must be taken to reduce the probability of educating the animal. 

            Rifle hunting strategies will commence depending on one of two variables.  Ideally, a significant portion of the sounder will be apprehended sometime in the first week.  When this occurs, or appears unlikely to occur soon, extensive hunts can be conducted to remove adolescent and adult pigs.  If scouting and analysis have been properly applied to indicate ideal shooting positions, the population will be significantly reduced following a few, well directed hunts.  Time allocated for this purpose is reasonably hard to predict, however, with constant attention and improved efforts this process should take no more than one or two weeks.

            Following these strategies, the present population will be significantly reduced.  Removal of smaller animals and juveniles will likely be the predominant effect.  Mature boars may provide the most challenging element to the controller.  Boars often behave independently of the group.  If boars or other elements have not been removed previously, at this point in the process hunting dogs can be introduced.  Dogs will be much more effective in addressing the boar because individual animals can be eliminated, or at least run off.  Dogs should not be implemented broadly prior to removal of the rest of the group.  Hunting with dogs in a target rich environment will most likely spread the problem rather than control it.

            Eventually, periodic scouting and/or hunting may be all that is required to retain positive control of wild pig reentry to the vicinity.  The effect of my control methodology remains theoretical.  However, I believe this combination of strategies will effectively address this issue if correctly implemented.  But, as mentioned in the introduction, ultimately, the will of the individual footing the bill will dictate the penetration level of the animal.