Sodium Nitrite
A toxicant using sodium nitrite as the active ingredient has been used to help manage feral hog populations in Australia, but at this time, is not labeled for use in the United States of America. As feral hog populations in the US have grown, interest in a chemical control option has grown as well. Before the chemical could be approved for use in the US, an extensive evaluation had to be conducted. This multipart study evaluated the effectiveness of the bait, risks to non-targets, risks to scavengers, and bait deployment methods.
Sodium Nitrite is fatal to other animals in addition to pigs, so the risk from non-target consumption must be considered. To help prevent consumption by other animals, field tests for sodium nitrite used custom feeders designed to only allow feral hogs to access the bait. While feeders were successful in preventing access to the bait, researchers discovered that the bait itself crumbled while being consumed. The crumbs created by feeding pigs were abundant enough to put native wildlife including migratory songbirds at risk. While suggestions have been made to minimize crumbling, the issue has not been solved yet.
Final field evaluations for sodium nitrite were completed in 2021, and all collected data was assembled in a packet and sent to the US Environmental Protection Agency. The EPA did not approve the use of sodium nitrite for feral hog management in the United States, and creators are working on methods to make the toxicant delivery system safer for native wildlife.
Warfarin
Warfarin based toxicants have been an approved method for managing rodents for many years. In 2017 a warfarin base feral hog toxicant named Kaput® Feral Hog Bait was approved by the Environmental Protection Agency (EPA) and registered for use with the Texas Department of Agriculture (TDA). Within weeks of that approval, the TDA registration was temporarily revoked until more information about the toxicant could be gathered.
In 2021, the Texas Legislature tasked Texas A&M AgriLife Extension with evaluating the effectiveness of the Kaput® Feral Hog Bait on the Texas landscape. The study found that when used appropriately, this toxicant can be a useful tool in reducing feral hog populations and damages on a property. A detailed report of study results was provided to the state legislature and TDA. After reviewing the report, the TDA chose to register Kaput® Feral Hog Bait as a limited use pesticide in Texas. This means that in order to purchase the product, applicators must have a valid private applicator license. For more information on how to acquire a private applicator license, reach out to your local County Extension Agent.
The product label states that this bait is only labeled for managing feral hogs and can only be deployed using a hog specific feeder. The label also describes a detailed pre-baiting process to train the pigs to operate the feeder and access the bait. Following label protocol is critical for success, but also to ensure that the product is being used legally. For more information on Kaput® Feral Hog Bait including the product label, information for applicators, and where to purchase the product when available, check out the Kaput® website.
Contraceptives
Contraceptives are a type of chemical control option that instead of removing the animal, prevents the animal from reproducing. This kind of management can be a very popular option in situations where space is too limited to utilize other control options or where lethal control may not be feasible for a variety of reasons. As with other types of control options there are pros and cons associated with contraceptives. The biggest “con” for contraceptives is that the feral hogs remain on the landscape continuing to cause the damage until they die of natural causes or other management efforts. However, when complete removal is not possible, managing to prevent population growth of feral hogs is better than no management at all.
Most contraceptives for mammalian organisms are sex specific. They either target egg production in females or sperm production in males. For the contraceptive to be effective, all members of the targeted sex must eat a large enough quantity of the contraceptive on a regular basis in order to remain sterile. In the wild, this can increase the cost of contraceptive use. Both male and female feral hogs will readily consume whatever food source is available, so managers will lose contraceptive chemicals to whichever sex is not the target. Additionally, if the contraceptive targets males, there are concerns associated with males from outside of the treatment areas passing through and fertilizing females while they are in heat. Female feral hogs will go into heat every 18 to 24 days until successfully bred, so depending on how wide spread contraceptive use is, there are likely ample chances for an untreated male to have access to the female at some point in time.