Wild boar (feral hogs in North America) are highly adaptable mammals with a global distribution. Their presence introduces a complex dynamic, particularly concerning other wildlife populations. While their general diet is overwhelmingly plant-based, wild boar do consume deer. Their impact is most pronounced on the youngest and most vulnerable members of the herd: the fawns. This opportunistic behavior places them in a unique role as both competitors and occasional predators.
The Omnivorous Nature of Wild Boar
Wild boar are classic examples of opportunistic omnivores, consuming a wide variety of food sources depending on availability and season. Their diet is primarily composed of plant matter, often accounting for around 90% of their intake. They locate items like roots, bulbs, and tubers by rooting with their snouts.
They rely heavily on seasonal resources, such as mast (acorns, hickory nuts, and beechnuts), which is a highly preferred and energy-rich component of their diet. Beyond vegetation, their omnivorous habits extend to invertebrates like insects, worms, and larvae, which they unearth while foraging. Small vertebrates, bird eggs, and carrion are also consumed when the opportunity arises. This generalist feeding strategy allows wild boar to thrive in diverse habitats and supports their occasional consumption of deer.
Predation on Deer: Targeting Vulnerable Prey
The consumption of deer by wild boar most often involves the predation of newborn fawns, which are vulnerable during their first few weeks of life. When a doe gives birth, the fawn remains motionless and hidden, relying on camouflage and lack of scent to avoid detection. This behavior, however, makes them susceptible to detection by a rooting wild boar.
The boar’s highly developed sense of smell frequently leads them to a fawn’s hiding spot, often finding the young deer incidentally while foraging. Scientific evidence, including stomach content analysis and game camera footage, confirms that boar consume fawns, sometimes leaving few remnants. Wild boar are not specialized deer predators like coyotes or black bears, but they will take advantage of a defenseless newborn.
In most cases, deer tissue found in a boar’s stomach represents scavenging of a carcass killed by another animal or vehicle, rather than a successful adult hunt. Active predation is limited to the most vulnerable individuals, such as a newborn fawn or a severely injured or sickly adult deer. The combination of a fawn’s limited mobility and the boar’s opportunistic nature makes the fawning season a period of heightened risk for deer recruitment.
Ecological Consequences for Deer Populations
The impact of wild boar on deer populations extends beyond fawn predation, creating multiple ecological pressures. A major concern is the intense competition for shared food resources, particularly high-energy foods like mast (acorns and nuts) that both species rely on for winter survival. Boar quickly deplete these localized food sources, forcing deer to expend more energy to forage or rely on lower-quality forage.
The destructive rooting and wallowing behavior of wild boar also significantly alters the deer’s habitat. This activity damages food plots and native vegetation, reducing the carrying capacity of the land. In areas with high boar densities, this environmental degradation compounds stress on the deer herd, especially during periods of hardship.
The combined effects of predation, resource competition, and habitat alteration negatively affect deer recruitment rates—the number of fawns that survive to join the adult population. While other predators like coyotes are often the primary cause of fawn mortality, the additional pressure from wild boar contributes to a lower survival rate. This factor is significant in localized areas where wild boar populations are dense and unmanaged, limiting the ability of a deer herd to recover.