March 24, 2011 - Busting feral hog myths
By Robert Burns AUTHORPHONE
OVERTON -- Until recently, if anyone tried to tell you how many feral hogs there
are in Texas, they were just blowing smoke, according to a Texas AgriLife
Extension Service wildlife biologist.
"When it comes to feral hogs in Texas, separating fact from fiction is becoming
a little easier as research reveals more about the pesky porcines," said Dr.
Billy Higginbotham, AgriLife Extension wildlife specialist. "There remains much
we don’t know about this exotic that has inhabited our state for the past 450
Highest ranking among the myths are estimates of the actual number of feral hogs
in Texas, Higginbotham said. A common number that has been bantered about for
years is 1 to 4 million. But there was just no data to support this estimate.
That is, there wasn't until Dr. Roel Lopez, associate director of the Texas A&M
University Institute for Renewable Natural Resources, recently used geographic
information system procedures to turn the guesstimates into reliable estimates,
said Higginbotham, who collaborated with Lopez on the study.
The term "geographic information systems," usually simply called GIS, refers to
a procedure that involves diverse data gathering means, from on-the-ground GPS
referenced data to satellite to historical records, and organizes it
"A simpler way to put it is that it’s just a electronic map," Lopez said.
Using GIS techniques, Lopez was able to quantify first the extent of the feral
hog habitat in Texas. He estimates that "approximately 134 million acres, or 79
percent of the state’s 170 million acres, represents feral hog habitat," said
By knowing the range of feral hog habitat and the species population density in
various types of Texas environments, Lopez also came up with a population
estimate that has some meat to it, Higginbotham said. Lopez estimates that the
actual number could range from a low of 1.9 million to a high of 3.4 million.
Exaggerated claims of feral hog population-growth rates are a related myth. Many
of the population guesstimates are based on a purely arbitrary number of hogs in
Texas being set at 1 million in the 1970s. This number, which also had no
research basis, is then often extrapolated on using another bit of
misinformation: That because of feral hogs' high birth rates, their population
is doubling every year.
So what are the facts?
A 2011 consolidation of past studies done by his graduate student, Janell
Mellish, the average litter size in Texas and the Southeast is 5.6 pigs, Lopez
It is also known, that on average, a sow is about 13 months old when she has her
first litter, and that also on average, mature sows have 1.5 litters per year.
This means there is a significant population growth rate, but a far cry from
the doubling-yearly myth, Lopez said.
"We estimated the population growth of feral hogs in Texas averages between 18
percent to 20 percent annually," Lopez said. "This means that it would take
almost five years for a population to double in size if left unchecked."
The study, which was conducted by Lopez and Mellish, used three methods to
estimate feral pig population growth in Texas: the statewide number of aerial
permits issued for shooting feral hogs; the number of pigs processed in
commercial processing facilities; and feral hog control data made available from
U.S. Department of Agriculture-Wildlife Services.
Another common myth is that recreational hunting alone can control feral hog
populations, Higginbotham said.
"Of the dozen studies conducted across the nation, hunting removes between 8
percent and 50 percent of a population, with an average of 24 percent across all
studies," he said. "In order to hold a population stable with no growth, 60 to
70 percent of a feral hog population would have to be removed annually."
Another myth is that it's possible to identify the breed of a given feral hog by
its color markings.
"Today’s feral hogs are descended from domestic breeds, Eurasian wild boars
and, of course, hybrids of the two," Higginbotham said. "But despite claims to
the contrary, simply observing the color patterns, hair characteristics and size
cannot let you definitively identify which of the three types and individual hog
One thing about feral hogs is definitely not a myth -- the huge amount of damage
they do to crops, wildlife habitat and landscapes, Higginbotham said. And from
all indications, the damage they do is expanding in scope and range.
"Feral hogs were once largely a rural or agricultural issue in Texas, inflicting
over $52 million in damage annually," he said. "But the porkers have literally
moved to town and are now causing significant damage in urban and suburban
communities. This damage includes the rooting of landscapes, parks, lawns, golf
courses, sports fields and even cemeteries, as they search for food. It has
been estimated that a single hog can cause over $200 damage annually."
The $200-per-hog estimate doesn't include the damage feral hogs do as they
compete with other wildlife species, such as whitetail deer, for food and
habitat, he noted. And some of the species challenged by feral hog invasions are
It's important to keep in perspective that the bottom line is not an actual
hog-head count, but the damage they do and how to develop ways to reduce it.
"For those landowners actively engaged in deer management, their tolerance of
feral hogs should be very, very low," Higginbotham said. "Can we (significantly)
reduce the damage feral hogs do through control efforts? The answer is
"Texas AgriLife Extension Service has demonstrated that through education and
outreach and Wildlife Services-led control efforts, damage can be significantly
reduced by control efforts," he said. "In a 2006-07 study funded by the Texas
Department of Agriculture, agricultural damage was reduced by 66 percent via
control efforts in just two years."
Since 2007, subsequent studies done by AgriLife Extension and again funded by
the state’s department of agriculture confirmed that control measures such as
trapping and shooting "prevented millions of dollars in damage by reducing feral
hog populations," he said.
"Landowners remain the first line of defense since Texas is 95 percent privately
owned land," Higginbotham said. "This means arming the public with Best
Management Practices and using various legal control methods to abate the damage
by reducing feral hog populations."
For more information on feral hogs, visit the AgriLife Extension website,
"Coping with Feral Hogs," at http://feralhogs.tamu.edu