Sounder Level Trapping

By: Josh Helcel, Extension Associate

 

 
 

As I travel around Texas learning and sharing information about wild pigs I hear many stories. From the 800 lb. “Hogzilla” that a hunter swears exists (Figure 1) to the trapped boar that jumped a 7 foot fence in a single bound, I have heard some really good ones. In between these stories I get the privilege to learn about various strategies being used to control expanding populations of exotic invasive swine. Some techniques are effective and often quite innovative while others – not so much.  Those that are routinely successful in trapping seem to share one common strategy: they use techniques and systems that target the entire family unit or “sounder” of animals in a single trap night.

 

Figure 1.  Adult boars (M) average around 200 lbs. and adult sows (F) average around 140 lbs. in the wild. Though rare, wild pigs exceeding 500 lbs. have been documented but generally cannot maintain this size without nearly continuous access to food resources.

 
 

There are a number of available tools for trapping wild pigs at the sounder level. Generally, larger corral style traps and a variety of either animal or remotely activated head gate or trigger systems provide the best chance for success. But it is not just the tools used; equally important are the factors of when and how they are implemented. This includes site selection and the pre-baiting process – the use of bait to acclimate wild pigs to a trap site over time. This practice is generally necessary to ensure an entire sounder is routinely entering the trap to feed prior to the trap night. But why would all of this be necessary in the first place? And more importantly, what kinds of practices should landowners generally avoid when seeking to trap an entire sounder of wild pigs?

 

 

Two common scenarios

 

Scenario 1.

Many landowners attempting to trap wild pigs go down to the nearest feed store and pick up a conventional box trap (Figure 2). The trap often ends up placed in a pasture right next to some rooting damage. It is then baited and set to catch the very first night. After a couple of days, the otherwise well intentioned landowner may capture 2 or 3 pigs in the trap. Perhaps the landowner catches another few pigs a month or so later and a couple more after that. The landowner eventually becomes frustrated when pigs will no longer enter the trap and it then sits unused sometimes for years until vegetation has grown in and all around it. This is a scenario that has played out time and time again, and each time this or something similar happens more and more pigs potentially learn to avoid traps altogether.  

 

Figure 2. Research found corral traps to be four times more effective than conventional box traps (Williams et al. 2010). Smaller conventional box traps often trap more juveniles than adults and can also lead to incomplete captures. 

 

Scenario 2.
A landowner seeking to reduce wild pig numbers sits in a box blind overlooking a feed site and has aptly used game cameras to time the arrival of the sounder right down to the minute.  Let’s say 14 pigs are in this sounder and they show up, right on time. The shot rings out and even finds its mark, and while there is now some “organic free range pork” ready for the freezer 13 pigs run off into the woods. Perhaps the shooter is successful several more times over the next month or two. Eventually the landowner notices that the remaining pigs have either left the area or have become increasingly difficult to pattern. They do not return to the feed site regularly, and the ones that do have gone completely nocturnal. What’s worse is that now there somehow seems to be more wild pig damage on the property than ever before.

 

Incomplete captures and trap avoidance

In Scenario 1 between 6 and 9 animals would have been captured over a period of around 6 months. These kinds of captures are known as “incomplete captures” and often remove individuals from one or more sounders of wild pigs. The remaining pigs in the sounder most likely witnessed or were nearby when each capture occurred, and this is considered by many to be the primary way in which trap avoidance is learned by these highly adaptable and intelligent animals. Because of this, removing an entire sounder in a single trap night is preferable to partial or incomplete captures of any kind including through the use of conventional box traps.  Keep in mind that while the pre-baiting process may take a week, several weeks, or in some cases a month or more it is much better than educating the animals to avoid traps in the future. When the entire sounder is comfortable and routinely feeding in the trap, it is then time set the trap to catch (Figure 3).

Figure 3. When the pre-baiting process is carried out correctly, the trap can ideally be set to catch on only one night in order to capture an entire sounder of wild pigs.

 

The wrong tool for the job

Scenario 2 illustrates how strategic shooting can potentially pressure wild pigs into becoming nocturnal and difficult to pattern while not removing even one sounder over a period of several months. In fact research shows that sport hunting usually does not reduce wild pig populations (Barret and Stone 1993). But this does not mean to avoid the practice of shooting altogether. Research shows it can be an effective tool in reducing agricultural damage by forcing pigs to abandon areas where they are causing damage (Engeman et al. 2007). And while shooting is not effective at the sounder level, it can be effective in targeting solitary boars or individuals that have previously become “educated” to avoid traps.  Ultimately, it comes down to selecting the right strategy at the right time to achieve your goals.  And when trapping wild pigs, more often than not this means removing an entire sounder at a time.

Conclusion

Texas A&M AgriLife Extension Service has made available numerous resources to help you to trap wild pigs at the sounder level. From Recognizing Feral Hog Sign to Training Wild Pigs to Bait to Placing and Baiting Feral Hog Traps, chances are you can find it on Our Website. There are over 30 videos on Our YouTube Channel, and a Wild Pig Management Video Series that will guide you through management techniques including corral trapping, box trapping, snaring, and strategic shooting. While the adaptability, intelligence and reproductive capacity of these animals can complicate successful abatement efforts (Mungall and Sheffield 1994), targeting wild pigs at the sounder level can increase the success of your trapping efforts. 

The following video will take you through the process of trapping at the sounder level. It provides insight in the entire trapping process detailed in the text above.

 

Wild pig resources listed below are available at the AgriLife Bookstore
– L-5523 Recognizing Feral Hog Sign
– L-5524 Corral Traps for Capturing Feral Hogs
– L-5525 Box Traps for Capturing Feral Hogs
– L-5526 Placing and Baiting Feral Hog Traps
– L-5527 Door Modifications for Feral Hog Traps
– L-5528 Snaring Feral Hog
– L-5529 Making a Feral Hog Snare
– SP-419 Feral Hogs Impact Ground-nesting Birds
– SP-420 Feral Hog Laws and Regulations
– SP-421 Feral Hogs and Disease Concerns
– SP-422 Feral Hogs and Water Quality in Plum Creek
– SP-423 Feral Hog Transportation Regulations
– L-5533 Using Fences to Exclude Feral Hogs from Wildlife Feeding Stations

– WF-030 Reducing non-target species interference while trapping wild pigs

 

 

 

 

 

For free educational programming or technical assistance with wild pigs please contact us:

Josh Helcel, Central and North Central Texas, 512-554-3785, josh.helcel@tamu.edu

Mark Tyson, South and Southeast Texas, 979-845-4698, mark.tyson@tamu.edu

Literature Cited

Barrett, R. H., and C. P. Stone. 1993. Hunting as a control method for wild pigs in Hawaii Volcanoes National Park: A report for resource management. Research division, Hawaii Volcanoes National Park Service, U.S. Department of the Interior, Hawaii National Park, Hawaii, USA.

Engeman, R. M., J. Wollard, H. T. Smith, J. Bourassa, B. U. Constantin, and D. Griffin. 2007. An

extraordinary patch of feral hog damage in Florida before and after initiating hog removal. Human–Wildlife Conflicts 1:271–275.

Mungall, E.C. and W.J. Sheffield. 1994. Exotics on the range: the Texas example, part II. The New Animals. Texas A&M University Press, College Station. 67–73.

Williams, B. L., R. W. Holtfreter, S. S. Ditchkoff and J.B. Grand. 2010. Trap style influences wild pig behavior and trapping success. Journal of Wildlife Management. 75(2):432–436.