Feral Pig Eradication Revisited

Feral Pig Eradication Cleveland National Forest and eastern San Diego County Revisited

In July 2014 San Diego County supervisors unanimously approved a campaign of feral pig eradication by trapping and shooting. This vote culminates the expensive and lengthy campaign to garner public support for the wholesale eradication of some hapless swine that were allegedly set free by members of an Indian tribe in order to establish a hunting program.

Studies and lengthy discussions about feral pigs in San Diego county began in 2009/2010. Driving parties in the SD feral pig eradication programs were the US Forest Service and The Nature Conservancy. Both are favoring or promoting the elimination of non-native species from sensitive environments. The US Forest Service is known for its grand-scale programs in several states to remove wild horses and burrows from habitats that are ‘needed’ for free ranging cattle. The Nature Conservancy zealously strives to return American habitats and environments to a pre-Columbian state. Whenever they get their hands on a property, ‘invasive species’ got to go. Good examples are Santa Catalina Island and Santa Cruz Island off the coast of California.

Yet, the two involved have a special relationship in San Diego county. While the conservancy has actively eradicated invasive species from properties they own or control exclusively (Santa Catalina and Santa Cruz), in the Cleveland National Forest the Conservancy actively meddled in the administration of public lands. National Forests are owned by the public and not by the Nature Conservancy.

The California Hunting Post became aware of the planned wild pig eradication in and around the Cleveland National Forest and in east San Diego county sometimes in late 2009. Subsequently we submitted a request for documents under the Freedom of Information Act. After a short battle over our qualification we received hundreds of pages from the Forest Service. They established a rather clear pattern. The US Forest Service cooperated with The Nature Conservancy in preparing and orchestrating an extensive public relations campaign. Goal of the campaign was to garner enough support among government entities, politicians and the public to get a radical feral pig eradication plan approved. The plan was designed to eliminate a wild pig population of between 600 and 900 animals. The Forest Service took the lead of an exploratory group. This group was designed to collect and present information on the effect of feral pigs on the environment, damage to agriculture and the fauna in general.

The names of prominent employees of The Nature Conservancy feature prominently in early correspondence between the Forest Service and the planning committee.  In fact, a top ranking Conservancy manager was instrumental in the very early stages of the public relations campaign and the planning stages for the feral pig eradication. He resigned from his position in the planning committee only in a later stage. His e-mails to other members of the planning group displayed the signature logo of the Conservancy.

The planners of the eradication program contracted with the San Diego Museum for Natural History to prepare a ‘scientific’ study on feral pigs in SD county, their effects on the environment, agriculture and health. The museum studied how wild pigs affect other wildlife, particularly endangered species, other big game (deer, etc.) and the damage done to natural resources.

The Forest Service in close cooperation with the Conservancy used the results of this study to formulate a plan for the eradication of wild hogs in the  Cleveland National Forest and in east San Diego county.

When I first saw the paper on wild pigs in San Diego county and why they needed to be eradicated, I immediately smelled a rat, ah, a pig. The proposal was clearly one-sided. It exaggerated the number of feral pigs, their expanding range, and the damage done to the environment in order to garner support for wholesale feral pig eradication.

The resulting public relations campaign followed a concept the Conservancy had established in feral pig eradication campaigns on Catalina Island and on Santa Cruz Island off the coast of California. The pattern is simple:

Find a few feral pigs where they do not belong (invasive species concept), malign them for the damage they do to flora, fauna and agriculture, identify an endangered species (preferably small and fragile) they eat or trample. Then list many other animals and plants they endanger by competing with them for food or other vital resources.

In the next step greatly exaggerate their numbers and overestimate potential population growth. For good measure throw in a few diseases feral pigs can carry and can pass on to domestic animals and humans alike. The final scare is to accuse the poor feral pigs of attacking feeble old ladies.

I know, I know, that is an exaggeration. But it is the proven concept wild pig eradicators are using over and over nationwide. Just follow media reports on wild pigs, damage done to the environment by the pigs and the suggested methods of dealing with them. Invariably it will be eradication by trapping and using professional hunters in helicopters. The justification for that? See above.

Vow, I just remembered that a group of professional hunters with helicopters were hovering in the background of the San Diego/Cleveland Forest planning committee. This very same group was involved in the eradication of pigs from the two islands. Coincidence? I do not think so.

Between 2010 and 2012 the California Hunting Post published several articles on the planned wild pig eradication. You can peruse some of them here:



My comments (admittedly acerbic and meant to ridicule) are here:



The San Diego Museum of Natural History collected and processed much of the materials presented by the planning group to government agencies, politicians, the media and the public in support of a wholesale eradication of the feral pigs. The museum diligently researched the SD wild pigs and their effects on the environment. Their research was mainly scientific and as unbiased as possible. The Conservancy, the Forest Service and the ‘planning group’ however felt at liberty to interpreted the scientific data to fit their overall goal. What goal? Wholesale feral pig eradication by professional hunters in their helicopters. 

At this point the ‘third party’ comes into play: Brave hunters in helicopters. There appears to be a lasting connection between the Conservancy and a group of professional hunters. They worked for the Conservancy on Santa Cruz Island. They proudly published a detailed and excellent report on their tactics and hunting methods that got rid of the Santa Cruz boar. Even their enemies must concede their professionalism and outstanding skills in planning and executing eradication campaigns.

I do not particularly like them. But they took on a difficult job and performed beyond expectations. I have no doubt that they will perform equally well in the San Diego campaign.

The Nature Conservancy and members of the planning group are an entirely different matter. They took the scientific study of wild pigs in eastern San Diego county and concocted a witches brew of exaggerations and half-truths to promote their goal.

For example, the planning group first leaked to the media and later openly talked about at least 600 to 900 feral pigs in the Cleveland National Forest and eastern San Diego county. They were the offspring of 20 or so domestic pigs that ‘escaped’ from their pen at in Indian Reservation. Twenty pigs turning into 900 pigs in the course of 4 to 6 years? Well, under good conditions pigs can triple their population in a year. Under good to excellent conditions. But not reliably and predictably. And hardly under drought conditions.

During their study researchers from the museum used several methods to locate and count feral pigs. The two most important were motion detection cameras and route surveys. The museum planted eight cameras. They installed them away from frequently used hiking trails to eliminate interference from humans. Two cameras were however placed on well used trails to check whether pigs used the trails as well. This is the camera positions shown in the actual report from the SD Museum of Natural History:

How many hogs did the Museum scientists track, find, photograph and count?

Here’s what they found between December 2009 and February 2010.

(SD Natural History Museum, Feral Pig Survey Report for the Nature Conservancy)

Well, they saw some pigs. And many more non-porcine critters. They saw more coyotes, deer, cottontail, wild turkey, ground squirrels, bobcats than wild pigs.

Surely there should have been more than 7 or eight pigs crossing in front of the cameras had the boar population been 900 animals.

The other method to locate pigs was the route survey. Museum workers conducted 24 route surveys. The routes varied in length from under 1 mile to about 18 miles. Each route was walked at least once, some multiple times to check for pig signs. The route surveys also included two surveys by boat.

The report from the SD Museum of Natural History sums up the route surveys:

Teams made a total of 199 observations, including one road kill and four trails. Tracks were the most common sign followed by scats and rooting.

Wild pig trail SD county. (SD Museum of Natural History)

The survey identified several core areas with wild pig populations. Their density did however vary greatly. Areas near the original ‘accidental’ pig release showed the highest density. The ‘Museum’ report prepared an aggregate depiction of areas with proven wild pig occupation in 2010. In addition, it identifies areas of the Cleveland National Forest and adjacent areas in eastern San Diego county that are in the path of the expanding hog populations. 

The legend to the above image reads: “ Extent of feral pig distribution in central San Diego County, based on pig signs as of February 20, 2010, plus two records near Lake Henshaw in March and May 2010. Orange and red shading represent confirmed occupied areas, at low and high relative density, respectively. Density is assumed to be low in areas with incidental reports not covered by survey routes. Yellow shading represents areas immediately adjacent to the confirmed occupied area with the most suitable habitat and dispersal routes, which are likely to be occupied soon if not already.”

The aforementioned route surveys charted feral pig signs, such as rooting, rub, scat, track and pig trails. The pictorial diagrams showed in 2010 the highest densities of signs at the lower section of the San Diego River north of Cedar Creek, in the upper section of the San Diego River (near the Inaja Memorial), and at upper Conejos Creek

Areas near “Inaja Memorial Park, along Cedar Creek Road, sections of Cedar Creek, sections of Boulder Creek, El Capitan Reservoir, Westside Road, Dubois Road, areas around Lake Cuyamaca, Oriflamme Canyon, and Deer Park Road” had lower densities of pig signs.

The authors of the San Diego study used the density of pig signs to estimate population density. They took into account findings in a study by R.A.Sweitzer and D. Van Buren. It was published in 2000 under the title “Estimating sizes of wild pig populations in the north and central coast regions of California”. (Journal of Wildlife Management)

His study placed the mean population density of wild pigs at between .7 and 3.8 pigs per square kilometer (1 km= 247 acres). Population density was lower in areas with high hunting pressure.

Based on data from the Sweitzer study, the San Diego Museum researcher estimated the population of feral pigs in the Cleveland National Forest and in eastern SD county. They concluded in 2010:

On the basis of comparisons to other sites in California with known densities, the current population size in San Diego County is probably within the range of 65 to 140 pigs, at an average density between 0.35 and 0.7 pigs/km2 (247 acres), across an overall occupied area of 200 km2 (75 mi2). This estimate is conservative, as it assumes that the average density is between half of and equal to the lowest density found by Sweitzer et al. (2000) in their study of seven California sites.”

Sixty to 140 wild pigs? That is a far cry from the 600 to 900 pigs allegedly tearing up the Forest and eastern San Diego county.

True, 140 wild hogs can easily make another hundred or more feral pigs under good conditions.  But what about hunting pressure? Even Sweitzer admits in his study that feral pig populations are less dense in areas with high hunting pressure. Moreover, drought is not exactly conducive to wild hog propagation either.

What other exaggerations served to blind side politicians, decision makers and the public into supporting the feral pig eradication program, you ask?

We will talk about that in part 2 of this featured article. Don’t miss it.


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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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