Feral Pig Eradication-Part II

Feral pig density and damage to the environment.

We concluded the first part with the question “ What other exaggerations served to blindside politicians, decision makers and the public into supporting the feral pig eradication program?”

Well, it took very little to fool politicians. They are no pig experts. Some did not even know that feral pigs are edible. Most other ‘stakeholders’, the media and the public fell for the usual vilification of wild pigs in general.

Off course, officials justified the proposed wholesale feral pig eradication in the Cleveland National Forest and on adjacent lands with the devastating damages the swine can do to flora, fauna, agriculture, water resources and the environment. Particularly when their numbers are spiraling out of control.

But how much out of control was that feral pig population? Let us have a closer look.

In cooperation with the the Nature Conservancy the planners commissioned a study of the status of the wild pig populations and its effect on the environment.

The purpose of this study “ was to document the distribution and status of the feral pig (Sus scrofa) in San Diego County on the basis of baseline data recorded by the San Diego Natural History Museum (SDNHM) for the Nature Conservancy and all relevant parties.”

Relevant parties” used the data gathered by the Museum to orchestrate an extensive public relations campaign. Its goal was to set the stage for final approval of the proposed feral pig eradication. The Museum researchers presented their report was in 2010.

San Diego county supervisors approved the final plan to eradicate feral pigs in July of 2014.

How dense is ‘dense’?

The Cleveland National Forest comprises about 720 square miles (1864 square kilometers). This does not include adjacent sensitive areas in eastern San Diego county that were threatened by wild pigs. According to the feral pig eradication planning committee an estimated 600 to 900 renegade feral pigs occupied the area. That makes for a feral pig density of between .33 and .48 feral pigs per square kilometer. The authors of the Museum study estimated the feral pig density to be between .3 and .7 pigs per square kilometer. (1 km= .39 square miles).

In California this is considered a very low wild pig density.

In his study of wild pig densities in Northern California Sweitzer put the average at  .7 to 3.8 pigs per square kilometer. He found that boar population densities were lower in areas with high hunting pressure.

Feral pig populations in the United States vary wildly. They range from a low  .7 pigs per square kilometer to a high of almost 10 hogs per square kilometer in Texas. A very learned study of the wild pig population on Fort Benning, Georgia, by Laura Hanson found in 2006 a boar density of between roughly 1 animal per square kilometer and a high of 1.9 pigs per square. Fort Benning is a military reservation almost the size of the Cleveland Forest. Hawaii is another state struggling with a very high density of pigs. It comes close to that found in certain Asian countries.

Worldwide pig densities

A study of wild pigs in Queensland found densities that varied between about 1 and over 40 pigs per square kilometer. The highest densities occurred in floodplains, swamp and woodlands.

European countries had rarely more than 5 boar per square kilometer. That has changed in recent years with an enormous population explosion based on excessive cultivation of maize for fuel. A Swiss study documented around 10+ individuals/km2 (Hebeisen). It is probably higher now.

This is also true for other European countries.

Reginald Barret published his collection of boar densities throughout the world as part of his study on feral hogs on the Dye Creek Ranch. (Reginald H. Barrett: The Feral Hog on the Dye Creek Ranch, University of California Division of Agricultural Sciences)

Pig density on the Dye Creek Ranch, a hunting ranch, averaged between 5 and 8 hogs on a 130 square kilometer study area. Kill rate from hunting was about 21 percent. However, the pig population still continued to increase. It takes a kill rate of between 70 and 80 percent to keep the size of a pig population stable. It can reasonably be assumed that not enough of the young hogs on the Dye Creek Ranch were shot.

Feral pig density in other parts of the world is mostly higher than in the contiguous United States.The highest hog densities are found in Asian countries. Up to 100 plus boar can roam the countryside. Between 27- 32 in the Ujung Kulon National Park, Java, and 32.2-72.1/km² in sugarcane areas in the Punjab, Pakistan (Encyclopedia of Life) .

Feral pig density and environmental damage

Wild pig density is closely related to damage to the environment. The higher the density, the more damage. Sweitzer et al found for example in the Henry Coe State Park in Santa Clara and Stanislaus counties that where the number of feral pigs was high, the animals had damaged over 36-65% of the total ground area. The highest pig related damage occurs in riparian areas with dense boar populations.

The authors of the Museum study of feral pigs in the Cleveland National Forest and in eastern San Diego county found rooting damage done by the invasive feral pigs “limited to less than 2% of the habitat in which pigs could dig. “

Two percent hog inflicted damage to the environment is a far cry from the hysteria and the urgency with which the planning committee promoted and demanded feral pig eradication in San Diego.

Sure, increased feral pig populations in San Diego county will result in increased damage to habitats. Yet because of the vast territory and the limited percentage of prime pig habitat within the area in question (Cleveland National Forest, etc.), it is unreasonable to expect pig induced damage to exceed standard percentages found in other places. In 2010 the authors of the Museum study estimated the number of feral pigs in SD to be “ probably within the range of 65 to 140 pigs . . .”. What? Only a hundred pigs or so? Does that justify eradication hysteria?

More exaggerations

Pictures released by the planning committee in their early communications with interested parties and stakeholders, intended to illustrate the damage done by the San Diego feral pigs, were grossly misleading.

The materials displayed only the worst pictures of damage wrought by wild pigs. A good example is the picture of the felled cattail that makes it look like the pigs felled large trees. And then the picture of two feral pigs standing in the middle of a trickle of water. It illustrates a text passage on the danger of feral hogs urinating into your drinking water. Or a water department employee urinating into a large water reservoir for drinking water, as we heard just recently. Are we now going to eradicate employees of water departments?

Well, pigs do urinate when they feel the urge. And so do cattle that are free ranging in our National Forests. I have yet to see the outrage over cattle mistaking a pristine forest creek for their lavatory. Moreover, the promoters of feral pig eradication conveniently forgot to mention that only a very small percentage of the water delivered to customers in San Diego county actually comes from local sources.

And since we are talking about free ranging cattle: They can be as destructive as feral pigs. For example, cattle have been implicated in the poor regeneration of oaks in California (Tyler et al. 2007). See, not only wild pigs damage oak seedlings. If you ever hunted on a private cattle ranch, you saw the damage and erosion free ranging cattle can do to the environment. I have seen enough of it to know that free ranging cattle do not belong in National Parks.

Why does the Forest Service not evict the cattle?

This question is easy to answer. Eviction of cattle is very difficult to enforce because it means fighting the windmills of tradition and strong commercial interests. Feral pigs have no lobby.

What difference does it make to a rare, endangered toad in San Diego county whether it is trampled flat by the hoof of a wild pig or by that of a free ranging cow? None, I say. It is flat dead either way.

More than one year ago I asked the Nature Conservancy about their position with respect to free ranging cattle grazing in National Forests. I am still waiting for a reply, of course.
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I credit the Forest Service for their guts in answering my question. The regional Forester told me that cattle are not an invasive species. They are livestock. Tell that the toad a cattle just stepped on. Are Holstein cows native to the Americas?

Enough of this silly stuff. The Museum study has another interesting piece of information nobody shared with you. The study included a list of areas most likely to be occupied by pigs in the course of future range expansion. It is a little too late for this piece of information to be of real value to local boar hunters. But you can give it a try anyway. Feral pigs are not eradicated overnight.

Areas most likely to become occupied within the next 12 months

(clockwise from the southwest side of the current range):

San Diego River below El Monte County Park

Silverwood Wildlife Sanctuary

Featherstone Canyon

Padre Barona Creek

Klondike Creek

Barona Mesa

San Vicente Creek, on the east side of San Vicente Valley

San Vicente Creek, in Himmel Canyon

Dye Canyon

Collier Flat

Wash Hollow Creek at Little Page Road

Witch Creek

Section 32, east of Witch Creek

Santa Ysabel Valley

Area surrounding Lake Henshaw including the San Luis Rey River

Santa Ysabel Creek, west of Highway 79

Santa Ysabel Creek, between Highway 79 and Volcan Road


Sentenac Creek

Orinoco Creek, both sides of Pine Hills Road

Paine Bottom

Pine Hills, including Dehr Creek

Cedar Creek, east of Boulder Creek Road

William Heise County Park

Harrison Park

Chariot Canyon

Mountain Meadows

Marston Meadow

Johnson Creek

Milk Ranch Road and La Puerta Springs

Paso Picacho Campground

Stonewall Creek

Upper Green Valley

Cold Stream

Sweetwater River at Green Valley Area Campground

Tule Springs Road east of Rancho Alegria

West Fork King Creek

King Creek, east of Boulder Creek Road

Poverty Gulch


King Creek, both sides of Conejos Valley Road

Sand Creek

Pine Grove, including sections 18 and 19

Peutz Valley

Chocolate Canyon

(Feral Pig Distribution Survey by the SD Natural History Museum for the Nature Conservancy, 2010)

Hot Hunting Links

The purpose of the Museum study was to deliver material for arguments supporting feral pig eradication in the Cleveland Forest and in eastern SD county. The planning committee and the Conservancy twisted it into a questionable justification for wholesale feral pig eradication.

Someone should have mentioned that feral pigs and boar can have beneficial effects.

We wrote about it in the California Hunting Post. 

Wild Pigs Grizzly Bears of California? 

Wild pigs as caretakers of the forest 

Commenting on wild pig eradication to name a few.

Arrinton et al. 1999 or Ford and Grace 1998 stated so in their reports. They opine that there is at least some indication that plant diversity in some instances may actually increase on localized scales in response to disturbance by pigs, e.g., if pioneering species move into areas that have been upturned by rooting pigs. And so did George Work, owner of the Work Ranch and well-known environmentalist in one of his speeches. This may be one extreme. But so is the complete vilification of feral pigs.

The proposal of the planning committee claimed to be an impartial evaluation of the benefits and disadvantages of several eradication methods. Yet for any clear thinking reader of the proposal it was obvious that the planners of the feral pig eradication favored one solution: Wholesale feral pig eradication using trapping, ground hunting by professional hunters and shooting wild pigs from helicopters.

And that is what the Forest Service (and the Nature Conservancy) finally got in July of 2014.

The promoters of the feral pig eradication spent thousands, tens of thousands or more, dollars on the public relations campaign. We know from materials received in response to our FOIA request that one public relations manager received 5,000 dollars per month for his efforts.

Was it worth spending all this money?

We say no, it was not worth it.

The Forest Service however holds that money spent now to develop the eradication plan and to execute it is money well spent. It eliminates much higher expenses later on for the eradication of a larger feral pig population.

You judge for yourself.

What can we learn from the San Diego feral pig eradication?

True, feral pigs can cause substantial damage to the environment, agriculture and infrastructure. They also carry diseases that can be transmitted to domestic livestock and to humans. The control of wild pigs is a necessary evil. I have no problem with culling wild pigs when necessary. But I have a problem with exaggeration and bending truth knowingly to promote a particular eradication method for the benefit of commercial interests. What interests? Maybe professional hunters in helicopters?

Is it necessary to eradicate an entire pig population in a vast area?

I doubt it. Hunting can put a damper on uncontrolled population growth. Under three conditions:

1. Hunters need access to hunt the animals on private land as well as on public land.

2. Hunters also need access to hunt feral pigs in parks and wildlife reservations.

3. Hunters need to understand the importance of killing the majority of young females in a sounder for overall population control. In combination with professional trapping hunters can keep feral pig populations under control if they place emphasis on culling as close to 80% of all young female pigs.

Unfortunately, two factors stand in the way of this method:

1. Landowners derive good additional income from access and guide fees they charge for hunting on their property.

2. As long as these exorbitant fees remain, no hunter in his right mind will kill a 80 pound wild pig and pay $ 500.00 or more for it. For that price any hunter will look for a trophy boar of at least 250 plus pounds.

What are the chances of property owners waiving or at least reducing fees to support wild pig control on their property? Slim to nil, I would say.

That leaves essentially only the traditional methods of feral pig control, professional trappers and hunters. Poisoning the critters is out at this time because of the harmful effects it can have on other wildlife. At least at this time I say, because other states continue to experiment with “safe” methods of using poison against wild pigs. Poison was briefly considered even by the planning committee for the feral pig eradication in the Cleveland National Forest and adjacent areas.

San Diego feral pig eradication is a special case

The San Diego feral pig eradication is a special case for yet another reason. As I pointed out above, the planning committee was strongly influenced by the agenda of the Nature Conservancy regarding the eradication of all invasive species. With it came the determination to use eradication methods practiced on feral pig populations on islands off the coast of California. Worse yet, a group of professional hunters came flying in on the coattails of the Conservancy. This group eradicated successfully in a well-planned and executed campaign several thousand feral pigs on one of the islands. Though it is nowhere stated in the official documents released to us in response to our FOIA request, this group was from the beginning favored as professional hunters of choice.

In 2008 ProHunt, Inc published a detailed report on the eradication of feral pigs under the title “A New Approach for Ungulate Eradication; A Case Study for Success”. When you read this report you will find the archetype of the eradication method favored by the planning committee for the feral pig eradication in San Diego county.

Was it a coincidence that the eradication plan favored by the promoters of the feral pig eradication so strikingly resembles the methods practiced by ProHunt on Santa Cruz Island?

I do not think so. Some of the actors in the an Diego eral pig eradication case are identical. ProHunt and the Nature Conservancy.

The sales argument?

Quoting from “A new approach for Ungulate Eradication”, ProHunt, Inc:

Recently, an island feral pig eradication was accomplished that successfully managed this risk and now provides a model for an efficient approach and methods that can be applied to eradication projects elsewhere.”

As in Cleveland National Forest and eastern San Diego county . ProHunt predicted in their report:

The Nature Conservancy and Channel Islands National Park, recognized the need for pig eradication and hired Prohunt Inc. of New Zealand to conduct the project.”

How thoughtful of them. And how wise and thoughtful of the Forest Service in charge of the Cleveland National Forest to avail themselves of the expertise and proven track record of the Conservancy and the ‘Island Restoration and Wild Animal Control Specialists’ from ProHunt, Inc of New Zealand.

We found them in a business directory for the City of Ventura. Ten to 20 employees and less than 500,000 dollars in annual sales. Type of business: Legal services. The FCC lists three radio licenses under their name. For their helicopter operations, I presume.

Does it surprise you that ProHunt, Inc. moved their offices from Ventura to Orange County right around the time of the public relations campaign for feral pig eradication in San Diego county?

Was their move a portent of things to come? Or just self-fulfilling prophecy. Or simply based on their close relationship with the Nature Conservancy?

I venture the educated guess that we will hear more, much more, about feral pig eradication campaigns carried out by ProHunt for the Nature Conservancy in many other parts and parks and in National Forests of this country.

Just listen to the steady drumbeat of anti-pig propaganda in the media of this country. All cite the same research studies, name the same diseases, exaggerate the damage feral pigs do and demand feral pig eradication at all costs. The public relations campaign in San Diego county for feral pig eradication is a good example for things to come.

Do not count on reason or moderation. The zealots of restoring wildlife and habitats of this country to the state before the arrival of Columbus will never tire to pursue their goal by any means. They will overlook hundreds of thousand of cattle roaming the land in the process. They will look the other way when powerful commercial and financial interests are at stake. A few unfortunate pigs will bear the brunt of the relentless attacks of fanatic interest groups.

Hunters beware

One more caveat. The San Diego feral pig eradication project exemplifies how the steady drumbeat of a relentless public relations campaign drowns reason, facts and truth. An untruth becomes truth if it is repeated often enough.

Currently the anti-feral pig sentiment is running high in the United States. Arguments against feral pigs and for feral pig eradication are repeated in state after state. And so are the recommended eradication measures. Fencing them in, trapping the drugged and radio-collared pigs, turning many of them into ‘Judas Pigs’ and shooting the rest from helicopters.

More importantly, the San Diego’s feral pig eradication program is to my knowledge the first project in California favored and promoted by the Nature Conservancy that is not carried out on land owned by the Conservancy. The islands were owned or in the exclusive care of the Conservancy. The Cleveland National Forest is public land. It belongs to the people of the United States and not to the Conservancy.

Yet, the environmental zealots of the Nature Conservancy seem to have established a solid foothold in government agencies trusted with the administration of our most cherished public properties. We can expect more San Diego-style campaigns. Trust me on that.




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Publisher and Editor in Chief at United Seabears
Peter Jaeckle is the publisher and Chief Editor of the California Hunting Post.You can find him also on Google+,Twitter, Facebook and on many other sites. Over the past decades he has written on investments, dogs and dog rescue, economic and on environmental topics.

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