Wild pigs (Sus scrofa) are considered opportunistic omnivores –meaning they will consume both plant and animal food sources available to them throughout the year. The vast majority of a wild pig’s diet consists of plant materials and an important, seasonal food source for wild pigs are mast crops (acorns, fruits or beans). Common mast producing species in Texas include oaks, hickories, honey mesquite, prickly pear cactus and persimmon.
Based on extensive research, feral hog diets consist of 88% plants, 10% animals, 2% fungi, and less than 1% other materials which include debris, garbage, lichens, rocks/gravel, soil/sand.
Mast crops represent a high-quality food source for wildlife and are consumed by many native Texas species including white-tailed deer, wild turkeys, collared peccaries and multiple small mammal species, including squirrels and rodents. Honey mesquite pods contain high concentrations of carbohydrates, some protein and several minerals, including sodium, calcium, iron, and zinc9. Acorns of both white and red-oak species are high in fat and carbohydrates, and contain some vitamins and minerals, including calcium and phosphorus8, 15. Acorns of the red-oak group have a high concentration of phenolics and tannins15, which are compounds that can reduce palatability to wildlife.
Acorns from trees in the red-oak group are considered semi-annual producers since they take approximately 15 months (two growing seasons) to mature, whereas acorns in the white-oak group are considered annual producers since they only take approximately 3 months to mature (one growing season). These crops are often available in large quantities for limited periods of time, mainly in the fall and winter months. Because mast crops often are distributed unevenly across the landscape, there is potential for competition among various species of wildlife for these resources.
The growth rate of wild pig populations has been shown to be correlated to the seasonal availability of mast producing tree species, and the yield of both previous and current mast crops influences the timing of reproduction and the proportion of reproducing sows in a given year.
Abundant mast crop availability also led to direct increase in fertility, indicating that wild pig sows adjust their reproductive output to track resource availability. Thus, sows born in years with high mast crop production should be heavier the next breeding season and potentially have higher fertility levels and larger litter sizes than sows born in years with low mast crop production. Therefore, litters born in a productive acorn crop year will have increased growth and future reproductive capability over litters born in unproductive years.
Invasive wild pigs also have the potential to change the species composition and diversity of forests through their consumption of mast crops, destruction of habitat and proliferation of invasive plant species. Continued wild pig control and damage abatement efforts remain imperative.
Lonnie Jenschke is an Erath County extension agent.