Other Considerations and Issues
Bounties
While paying bounties are often raised as a solution to decreasing the feral swine population, they are not likely to be effective and, in some cases, may lead to an increase in feral swine populations. For example, bounties may encourage some trappers to release females and young animals to leave enough “seed” for future trapping. Likewise, bounties may contribute to the spread of the feral swine population if trappers illegally move them to new areas. Even when this doesn’t occur, the increase in food and energy resources used to attract feral swine to the area can contribute to increased reproduction due to the increased availability of bait used in the trapping and bounty program.
This was observed at Fort Benning, Georgia, where a feral swine bounty program from 2007-2008 resulted in a take of 1,138 pigs at a total cost of $57, 296 or $50.35 per pig. In the bounty area, researchers found the feral swine density increased between 23 – 130% while sounder size increased 144 – 233%. The number of juvenile feral swine per adult increased 191-219%. Increased food availability likely attracted feral swine to the study area and reproduction increased.
Bounty systems may also result in fraudulent claims, as observed in other states. To be effective, any bounty program at the state or county level must increase harvest above the current level (200,000 feral swine annually in Georgia). Paying hunters and trappers to harvest feral swine would require payments for all the feral swine currently harvested for free, and then additional dollars to increase mortality in order to drive down the population. Any such program would be prohibitively expensive and ineffective. Large scale trapping and education programs are more cost effective in the long run.
Poisioning
Currently there are no state registered toxicants or poisons available for controlling feral swine populations, and it is illegal to poison feral swine in Georgia. However, there is a great deal of ongoing research to identify and register a toxicant that can be used to combat the overabundant feral swine population. An effective toxicant could be a powerful and cost-effective tool, one of many for reducing feral swine numbers. However, the greatest hurdle is finding a poison that can humanely kill feral swine while having little effect on non-target species. There are currently two primary poison controls under development with feasibility in the United States, however if any come to market they would be extremely restricted use. These are:
HOG-GONE® (active ingredient sodium nitrate) is also undergoing trials in both Australia and the United States. Issues related to bait acceptance by feral swine, non-target toxicity, and registration hurdles related to testing a new toxicant suggest the product may be 3-5 years from the commercial market, but likely only as a restricted use pesticide. Read more about domestic research here.
KAPUT™ (active ingredient warfarin) in currently under development by a commercial company in the United States. Like sodium nitrite, feral swine will not readily consume warfarin so the drug must be carefully concealed in special bait formulations. Testing is underway on the efficacy of KAPUT™ for use as a feral swine toxicant.
Contraception
Currently there are no state registered contraceptives available for controlling feral swine populations, and contraception in feral swine is illegal in Georgia. Development of an effective contraceptive for any animal faces several challenges.
The contraceptive should not produce any adverse reactions in target animals.
It has to be administered in the field.
It cannot have any non-target species risks. Also, it cannot affect animal behavior: this includes not only social behavior but breeding behavior as well.
Animals that received the contraceptive and are then taken for human consumption may pose an unacceptable risk to the hunter or trapper.
In feral swine populations, delivery mechanism may be more costly and ineffective than whole sounder removal trapping. Though relatively easy to treat individual captive animals, it is not easy to effectively treat large numbers of free-ranging individuals. Therefore, contraceptive use as a population control agent is not effective and it is unlikely they will be used in feral swine management.