State researching ways to safely poison feral hogs

It took 30 years of poisoning, trapping and shooting to eliminate the feral hog population on 144,576 acre Santiago Island, but Louisiana is no island and right now, poisoning the state’s estimated 500,000 wild pigs is not an option.
“Poisoning is cheaper than trapping,” said Dr. Glen Gentry, reproductive physiologist at the LSU Ag Center Dean Lee Research Station. “That (poisoning) is what we are moving toward.”
“It will take some time to get there.”
Gentry is conducting hog control research at both the LSU Ag Center Dean Lee and Idlewild research stations, and the research is focusing on bait mediums and systems for delivering poison specifically to feral hogs without endangering any other animals. Texas is also has a hog control research program. Poison is currently being used to combat the pig problem in Australia, but there are several factors being studied before chemical control of hogs can be legally used in the United States. Chemical controls must be also approved by the U.S. Department of Agriculture and the Environmental Protection Agency.
“Here in Louisiana, the black bear is of huge concern when it comes to the poisoning of hogs,” Gentry said. “We don’t know how much of it it would take to kill a black bear, and we are obviously not going to test it on black bears.”
“The poison delivery system is a big issue. HAM -- the Hog Annihilation Machine -- is made by a guy in Dehnam Springs. It actually recognizes pig sounds and only opens its hoppers for pigs, and it shocks animals that touch it when the hoppers are closed.”
Right now, Gentry and others at the research station are testing which scents and flavors, including fruits, corn and even earthworms, appeal most to hogs.
“So far, whole shelled corn is the overall winner and serves as the control for our experiments,” Gentry said. “Fish is showing some promise. These studies are ongoing.”
The next phase of research will be methemoglobin reductase tests using blood samples from non-target species to determine the lethal dose of sodium nitrite.
Feral hogs have spread to almost every state in the continental United States, and last year, the U.S. Department of Agriculture pledged $20 million toward controlling feral swine.
“People are the common denominator of the hog problem,” Gentry said. “People kept them for shooting range hunts, and they were escaping. In the 1980s, they were just in the southern United States and out west. Now there are only just a few states that don’t have a hog problem.”
Using high reproductive rates and fairly high mortality rates, Gentry calculated that in 64 months, one female pig and her subsequent offspring can result in approximately 1,000 more pigs on the landscape. By LDFW estimates, there are about 10 pigs per square mile. During the 2013-2014 hunting seasons, hunters killed 183,600 feral hogs and only 166,200 deer.
Gentry spoke to farmers in Evangeline Parish earlier this year during the annual Rice and Soybean school, and the subject of feral hog control was of particular interest to the famers and landowners who deal with hogs destroying their land and crops.
“Hogs have a negative impact of $1.5 billion annually in the United States,” Gentry said. “They are costing famers in Texas an average of $10,000 a year each.”
“They are damaging soybean fields. It has also been observed that they prefer medium grain rice over long grain rice. They will actually walk around long grain to get to medium grain.”
After he finished his presentation, Gentry opened the floor for questions.
“I doubt any of the farmers in this field have seen a bear in their fields,” one farmer said. “I know most of them have seen hogs in their fields.”
“It would take only one black bear dying of poison to shut poisoning hogs down completely,” Gentry said.