TPWD News Release — March 13, 2007
AUSTIN, Texas — Problems with exotic, invasive plants and animals—species that did not evolve in Texas and don’t belong here—continue to worsen statewide. One escalating issue involves feral hogs, which have been a problem for decades on rural ranch land, but in recent years have begun to cause damage in cities.
Some urban parks and preserves, including Armand Bayou Nature Center near Houston and the Forth Worth Nature Center and Refuge, have had to trap and remove feral hogs. Some residential areas are also reporting hog problems. This winter, animal control workers were called to the LakeRidge neighborhood in southwest Lubbock after residents complained of a wild hog strolling through the golf course.
Hog problems have declined in recent years at Armand Bayou in Pasadena, probably because nature center fencing helps keep new hogs from coming in, and because they’ve trapped problem pigs in past years. But just outside the nature center fence, it’s a different story.
“We’ve had a tremendous development boom in the area around us, with new houses, buildings, and industry,” said Mark Kramer, Armand Bayou stewardship coordinator. “As a result, a lot of wildlife habitat loss is taking place around the nature center. We have a six foot chain link fence around the perimeter, which helps limit hog immigration to our site. However, surrounding neighborhoods in the past few years have made the six o’clock news because of hog damage in the yards of expensive new homes.”
The Fort Worth Nature Center’s hog management program was highlighted at a recent urban wildlife conference in Dallas, where it was hailed as a national model for building consensus and controlling nuisance wildlife effectively and humanely. The 3,621-acre refuge, said to be largest city-owned nature center in the nation, includes forest, prairie and Trinity River bottomland habitat, all inside the city limits.
“Feral hogs can root several feet into soft soil, eating invertebrates and the bulbs and rhizomes of plants, so they’re having negative effect on the plant community as well as wildlife,” said Rob Denkhaus, natural resource manager for the city-operated Fort Worth Nature Center.
“They can be predators on some wildlife species such as ground-nesting birds, reptiles and amphibians and the like,” Denkhaus said. “So their impact is far-reaching, and all negative.”
Rick Taylor, a Texas Parks and Wildlife Department wildlife biologist in Uvalde and author of the booklet “The Feral Hog in Texas,” would agree.
“Feral hog activity can destabilize wetland areas, springs, and creeks by excessive rooting for food, trampling and wallowing,” Taylor said. “In addition to wetland habitat destruction and alteration, hogs can damage trees. While not active predators, wild hogs may prey on fawns, young lambs, and kid goats. If the opportunity arises, they may also destroy or consume eggs of ground nesting birds, such as turkeys and quail.”
Taylor says early Spanish explorers probably were the first to introduce feral hogs (Sus scrofa) in Texas more than 300 years ago. In the 1930s, European wild hogs or “Russian boars” were first introduced to Texas by ranchers and sportsmen for sport hunting. Most of these eventually escaped from game ranches and began free ranging and breeding with feral hogs. Because of this crossbreeding, there are very few, if any, true European hogs remaining in Texas.
A mature feral hog may reach a shoulder height of 36 inches and weigh from 100 to more than 400 pounds. Feral hogs are true pigs, but native javelinas belong to a separate family of mammals. Javelinas are smaller, have an unnoticeable tail, a grizzled-grayish coat with a white band of hair around the shoulder or "collar," and are more social or herd-like animals. Although feral hogs and javelinas inhabit the same range, they are not compatible. No exact numbers exist, but wildlife biologists estimate there are more than 1.5 million feral hogs in Texas.
Feral hogs are unprotected, exotic, non-game animals which may be taken by any legal* means or methods at any time of year. There are no seasons or bag limits. The only requirements to hunt them are a valid Texas hunting license and landowner permission. In most cities, local ordinances make it illegal to discharge firearms, and public attitudes and safety concerns make hog control more complicated.
Such was the case at the Fort Worth Nature Center, which began noticing a growing hog problem around the year 2000.
“When we first saw rooting in sandy soil, we thought it was coyotes following pocket gopher burrows,” Denkhaus said. “But eventually we started seeing hogs every day, including a couple of troubling encounters between people and hogs. We saw more and more environmental damage, particularly in wetland and bottomland hardwood areas.”
The nature center staff and supporters realized something had to be done. But an urban nature center is not like a rural ranch. The idea of trapping and killing hogs generated some controversy. Denkhaus and a team of others went through a long process that ended up taking two years, but eventually they developed an approach that all stakeholders could live with.
“Hog control is not rocket science,” Denkhaus said. “It means lethally removing hogs from the area. We wanted to do it in the most humane way possible that would allow the animal welfare community to accept it, and we also wanted it done safely.”
Pigs are nocturnal so they usually get into nature center traps overnight, and the staff checks them at first light, minimizing the time animals spend in the live traps. To minimize stress on the animals, from the moment workers approach them, Denkhaus says it takes an average of just four minutes to dispatch all animals in the trap.
Disposing of the carcasses turned out to be another issue. Many people would have loved to see the meat go to needy organizations such as homeless shelters, but the nature center ultimately chose to leave the carcasses on site.
“The pigs, as uninvited visitors to the refuge, have been using the natural resources since they got there,” Denkhaus said. “So we’re putting the natural resources back into the natural system, and we’re also avoiding potential problems and liability for the city with disease transmission from the meat. They decay on site, which means we’re feeding our scavengers, our decomposer groups, we’re building new soil through the nutrients going through, and you can even see some changes in the plant community there. It’d be similar probably to the time when herds of bison came through and you had a one ton bison dropping and decomposing in place.”
Since the program began, Denkhaus says environmental damage at the refuge has decreased significantly, proof that the hog control program is working.
The Fort Worth story illustrates what is believed to be a growing problem.
“I have other communities calling, asking how we did it, which tells me other people are having the same problem,” Denkhaus said. “Feral hogs are spreading just as the human population is spreading, so it’s only natural that the two populations are going to collide. Anywhere you have a river bottom type corridor coming into a city, you’re going to have the opportunity for pigs to be following it right into town.”
Taylor’s booklet “The Feral Hog in Texas” is geared primarily to rural settings, but it features a wealth of general information describing feral hogs and control practices, including specifications for building and deploying traps. An online version of the booklet resides on the TPWD Web site, where it can be viewed as HTML Web pages or downloaded and printed in .pdf format.
* Correction, March 15, 2007: The original version of this news release omitted the word “legal” from this sentence. (Return to corrected item.)
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