Changes in wildlife population have been occurring for many years. One of the major problems seen today is the rising population of feral hogs. According to Dale Rollins, Texas AgriLife Extension wildlife specialist, the population of feral hogs is increasing annually at a rate of 20 percent. The current range of feral hogs includes 44 states and four Canadian provinces.
Is it conceivable that marauding pigs are the only cause for quail decline in recent years? Not likely. However, it is very likely that pigs could be one contributing factor.
Feral hogs impact the quail population in three areas: Nest depredation, habitat “damage” and the nuisance impacts on supplemental feeding.
Nest depredation serves to be the greatest threat. Hogs are opportunistic omnivores that possess one of the keenest olfactory systems in the animal world. This doesn’t bode well for birds that nest on the ground. Results from a study conducted in the summers of 1992 and 1993 conducted in the Rolling Plains on “dummy” quail nests showed that over 30 percent of nest depredation on simulated nests could be attributed to feral hogs. Since those experiments, researchers learned that feral hogs can be dainty eaters, leaving essentially no physical evidence at the nest site (i.e. no rooting); therefore, those assignments of feral hog damage in the 1992 and 1993 study were probably conservative.
There’s no question about the plundering pigs’ nuisance capacity when it comes to supplemental feeding, whether they’re marauders in a food plot or porcine-guerillas around one’s quail feeders. Rollins states that he has seen only one truly hog-proof quail feeder. A manager in Archer County cements steel legs in about two feet of concrete welded onto 16-inch casing. To his knowledge, the feeders have not been breached in the past 10 years.
According to Rollins, there is one more potential impact on quail from feral swine. Surprisingly, it is as a reservoir for tularemia or “rabbit fever.” A researcher at Texas Tech University, Dr. Steve Presley, recently found 15-50% of the feral hogs from central Texas showed evidence of current or past infection with tularemia.
Given their rapid rise to “popularity”, the question begs “why so many…now?” Why have the populations increased so much in the past 20 years? Dr. Rollins offers six factors that, in concert, have created the perfect storm for burgeoning pig population.
- Biotic potential- This phase relates to how quickly a species can propagate in the absence of limiting factors. (i.e. birth rate, litter size, age of first breeding, lifespan and survival). Sows excel in most of these categories.
- “Critical mass”- Most areas in Texas have a “source population” of wild hogs via natural expansion or questionable stocking efforts. Now the population has reached the point in its “growth curve” where populations are increasing at a rapid rate, thought to be about 20 percent per year.
- Absentee landownership patterns – The mix of traditional farmers and ranchers evermore interspersed with absentee landowners with a wide range of management goals often complicates any attempt at formal, concerted control efforts.
- Wariness- Hogs aren’t stupid. They adapt quickly in the presence of persecution. They become strictly nocturnal. Their senses of smell and hearing are incredible, giving them a strategic defense against hunting.
- Ineffectiveness and Inefficiency- Too often our attempts at control are ineffective, or at least inefficient. Probably the most common method of control is trapping, and traps can work quite effectively. Trouble is, most managers use a cage-type trap that typically catches only one, or at most a few, pigs at a time, leaving the rest to become more difficult to trap. A better approach is to use a much larger corral trap where the entire sounder can be trapped at one time.
- Hippocratic oath- First, do no harm. Texans feed about 6 million bags of “deer corn” annually, some 300 million pounds! How much of that winds up consumed by a hog, instead of the intended target? Complement a diet of corn with an unknown amount of pelleted protein rations also aimed at deer, and you’ve got a perfect breeder ration. Hence, unwittingly we end up increasing the ovulation rate of sows, not to mention increasing pig survival via better nutrition.