Accelerated Growth of Wild Boar Populations in California - How Fast and How Soon? - California Hunting Post

Accelerated Growth of Wild Boar Populations in California – How Fast and How Soon?


After years of drought we finally had a wet winter 2009/2010. Much of our water resources are replenished and there was a sufficient and lasting snow cover. Habitat conditions throughout the state improved greatly, with the exception of marginal areas close to deserts. New growth above and below ground was strong in spring. This provided much more beneficial habitat conditions to the fauna. Therefore, overall environmental conditions for almost all living things, flora and fauna, are better, much better, than in previous years.

For the animals of the forests and grasslands more and better food supply inevitably means more offspring. Wild pigs are no exception to this axiom. The only question is how long will it take before ample food and better habitat translates into more wild pigs.

As we have seen in previous articles, wild pigs have more and larger litters under beneficial food and habitat conditions. They may produce more than one litter a year. The survival rate of piglets also increases drastically under good environmental conditions. While the survival rate in marginal years can fall as low as around 10 percent, it hovers between 40 and over 50 percent in good years. In agricultural areas with plenty of vegetable fields, barley, grapes, root vegetables and plenty of corn (mais) it can even go higher. Let us also not forget the influence of relatively warm winters. Less severe winter weather results in higher piglet survival rates. You can read more details in the article “Boar Population in California 2010 – Quo Vadis” published here earlier this year.

These are the reason for the very rapid expansion of boar populations in European countries where enormous corn fields have become more prevalent than ever before. Corn is used for ethanol production. Wild boar love it and thrive on it.

Wild pigs in California profit greatly from any improvement in the factors mentioned above – just as their European wild cousins. However, the availability of water is of utmost importance in our dry and hot climate. Wild pigs need plenty of water to sustain life. They seek it out early in the morning and visit water sources late in the afternoon before retiring to their bedding areas.

And without water the growth of plants is stunted leaving boar with little to feed on in their natural environment except for the crops in irrigated fields, your ornamental flowers and bushes in your front yard and the grubs and worms under your carefully watered lawn.

Before moving on to an update of the current status of wild pig populations and an outlook on fall and winter 2010, let us consider briefly one other important factor of wild pig reproduction. Boar and wild pig sows are much more prone to producing multiple litters per year and to having larger litters in years with an excellent mast harvest. The more mast (assorted nuts) is available in fall for the wild pigs to gorge on, the better nourished the sows and the larger and healthier the litters will be.

Mast harvests are best after wet winters when rain and runoff have penetrated deep into the soil thereby dissolving nutrients and feeding them to the trees through lasting moisture. We could therefore conclude that this coming fall should produce a bumper crop of mast of all kinds. Wild pig populations consequently should expand rapidly.

“Not so fast’, says Jeff Cann, Wildlife Biologist for the Department of Fish and Game for Monterey County, California.
“Mast productions does not necessarily increase considerably in the year of a wet winter, but is much more likely one year after heavy winter rainfall and snow. It can occur even later. There is no predictable pattern. We will have to wait and see.”

True. I ventured the guess months ago that we will notice the earliest increase in wild pigs later in fall of 2010 at best. Wild pig populations will thereafter increase at an accelerated rate in spring of 2011 and reach significant numbers in fall of next year. How soon and how fast wild pig populations will grow depends much on the quantity and quality of mast and when it becomes available.

“The drought years decimated wild pig populations in much of the state. Even private lands that previously held many boar became almost devoid of pigs,” states Jeff Cann.
“Where we would see up to 100 pigs at a time, we frequently could see maybe twenty or thirty at best. But this will most likely change in the course of the coming year.”

This sentiment is shared by other wildlife experts. In early 2010 I contacted Don Geivet, Vice President for wild Pig management at the Tejon Ranch. He told us at that time:

“We are already seeing good reproduction rates and larger litters despite a mediocre mast harvest. Seed conditions are good. Our wild pigs profit from plenty of new plant growth and shoots. Expect a first peak in piglets right around early September.”

And Marc Kenyon, the new Statewide Coordinator for Bear, Mountain Lion & Wild Pig Programs, Department of Fish & Game, California, put it this way:

“. . .wild pig populations in California “. . . continue to increase, according to annual harvest records. Approximately 90% of the wild pigs killed in California are shot on private lands. The recent drought has decreased the rate at which the wild pig population has been increasing, however the spring rains this year are anticipated to bring on a bumper crop of acorns and provide wallows and free water for rearing piglets . . . (As such,) we anticipate the population to continue to increase statewide. The heart of the wild pig population continues to be in the central coast region, in and around the Salinas Valley. Depredation filings and pig damage complaints remain high in that area.”

I have not troubled to contact ranchers and hunting guides for the simple reason that even in bad wild pig years their business interests dictate that there are ‘plenty of trophy boar on the ranch’ waiting to be taken. Of course.


Several of my hunting friends spent a lot of money on boar hunting, guided and unguided, on several private ranches. Result? Zero signs or only old signs and no boar. This includes Fort Hunter Liggett.

No wonder. If a wildlife biologist can see maybe 20 or 30 wild pigs where there used to be 100 or more than an average hunter will most likely see not even one. Wild pigs at FHL sustain great hunting pressure and so do boar on many private hog hunting ranches with active boar hunting events every weekend.

I attempted several times to contact the Wildlife Biologist for the County of Dan Diego. My calls were not returned. However, the San Diego DFG office stated that they are aware of 200 to 300 boar in their jurisdiction. The population is steadily expanding along creeks and watersheds from the location of the original accidental release into the Cleveland Forest. The Forest Service prepared maps showing where boar are found. Yet the wild pigs have already broken out of their ‘homelands’. Newspaper reports allow the conclusion that the wild pigs already are expanding beyond the borders of the known boar territory and are drawing closer to population centers.

The boar are found in very difficult and challenging terrain. The ‘natives’ are hostile. They do not welcome out of town hunters. A local restaurant owners dreams of boar meat and of wild pig BBQ ribs on the menu. . Yet others already complain about the dangers wild pigs pose to their cats, miniature poodles and guinea pigs – not to speak of their lawns and rose bushes.

The outlook for 2010 and 2011?

The wet winter brought relatively good habitat conditions. Sows restored their health and are in breeding mode. The early 2010 litters will most likely not be unusually large or frequent. Barring exceptionally hot and dry weather for the rest of the year and a dry and warm winter, wild pig populations in California should slowly begin to increase towards the end of this year.

Says Jeff Cann: “ I am not quite sure yet, but it looks like I am seeing more wild pigs these days.”

In the course of 2010 sows from the early litters will enter breeding age thereby increasing the ranks of the ‘older’ sows considerably. We can expect to see multiple generations of female wild pigs busily producing offspring. The first ‘improved’ litters from 2010 should enter the breeding cycle around spring/early summer 2011. The resulting population growth will not be dramatic at first. On the other hand, if you consider the ability of sows to have multiple litters, the relatively short gestation period and the early maturity of sows, it becomes apparent why under favorable habitat conditions boar populations can grow at an almost viral rate.

Therefore, if we see good to excellent mast production later this year (2010), expect a significant acceleration of the birthrate and an increase in litter sizes in late spring of 2011. Breeding sows should be in top condition and therefore produce large litters; their female offspring from the second half of 2010 and early 2011 will add their own piglets to the litters of the older sows.
The resulting growth in the number of wild pigs in California could be spectacular.

If it is, hunting boar in California will again be more promising and exciting than during the last boring years of drought when, according to guides, ranches were ‘overrun by herds of vicious, aggressive wild killer boar’ – mostly invisible to the average hunter.

If your hunting time and hunting dollars are limited, you might consider waiting till late this year or early next before you strike out in order to confront one of the vicious stealth boar that got away from a private ranch. And when you go, select a ranch that does ‘good things’ for their boar, such as planting barley fields. Barley magically attracts wild pigs just like catnip summons cats.

If all else fails and I am way off, you can always play it safe and visit the Big Horn Ranch. Or make a deal with Native Hunt for a true European boar. Or visit one of the other hunting ranches that either have a stable breeding boar population or stock the ranch when necessary.

After all, what is worse: Hunting on a ‘high fence’ ranch or stalking wild pigs in a considerate rancher’s barley or corn field?
Both deliver a wild pig to your table.



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