Trapping probably is the most effective feral hog control technique available to most land managers. Aerial gunning can be fairly effective but should be implemented over large areas (a few thousand acres), requires a helicopter, and can be relatively dangerous considering the necessary low altitudes and slow speed. Ground hunting is fun but not particularly effective at reducing swine populations. No toxicants are legal but are being investigated.
Many different trap technologies are available: cage or box traps (Figure 1); circular spring panel traps — probably the least effective among the options discussed here — (see example at bit.ly/SpringTrapPhoto); corral traps (Figure 2); drop nets; BoarBuster; and others.
Trap size should be matched to feral hog sounder size. A sounder is a herd of feral hogs primarily comprised of one or more adult sows and one or multiple generations of offspring. A sounder is the primary social unit among feral hogs. One or more mature boars will spend time with a sounder when trying to mate with a sow but then will move on searching for another sow.
The goal when using a trap should be to capture an entire sounder at one time. Feral hogs are relatively intelligent and can learn quickly, so a portion of a sounder remaining outside a tripped trap often learns to avoid the trap. Cage or box traps can be effective management tools when dealing with small sounders, e.g., less than six individuals or individual boars. Cage or box traps may capture many hogs over time when hogs are abundant but usually do not capture enough whole sounders to prevent population expansion and train many feral hogs to avoid traps. When dealing with sounders comprised of more than about six individuals, larger traps such as corral traps, drop nets or the BoarBuster are more appropriate.
In past years, corral traps and drop nets represented some of the best known tools for capturing feral hogs. However, ongoing research at the Noble Foundation led to the development of the BoarBuster trap. BoarBuster (available commercially in 2015) marries the technology of remote monitoring and triggering with the best aspects of previous trap designs. BoarBuster captures whole sounders with a single trapping. In testing, the trap captured as many as 39 feral hogs in a single drop.
Appropriate baiting and training protocols should be practiced to increase the likelihood of trapping a whole sounder. Use of infrared-triggered cameras is very helpful to learn sounder size and pattern feral hog activity. It is important to remove feral hogs from a trap as quickly as practical. Other sounders or individual feral hogs might travel by a trap containing hogs and learn to avoid it. Also, it is unethical to leave trapped animals in a trap very long because they might escape, injure themselves or others, or suffer due to weather exposure or anxiety. When a trap cannot be checked at least once a day, it should be shut, tied open or removed so it cannot capture animals, especially non-target animals. For more information, visit noble.org/feral-hogs/.