Yes, wild boars, more accurately called feral pigs (Sus scrofa), are widely distributed across the Hawaiian islands. These non-native, highly invasive animals pose one of the most severe threats to Hawaii’s unique native biodiversity and agricultural resources. Their destructive foraging habits have cemented them as a major land management challenge across the major islands.
Arrival and Historical Context
Pigs were introduced to Hawaii in two historical waves, resulting in the current hybrid population. The first occurred between 400 and 700 A.D., when Polynesian voyagers brought small, domesticated pigs, known as pua’a, as a source of protein and a valued cultural resource. These early pigs were primarily of Asiatic swine ancestry. The second, more impactful wave began in the late 18th century with the arrival of Western explorers. They introduced larger European wild boar and domestic stock, often for sport hunting or as a readily available food source for future voyages. The interbreeding of the smaller Polynesian pua’a with these larger animals created the robust, genetically mixed feral pig that now inhabits the Hawaiian forests.
Island Distribution and Preferred Habitats
Feral pigs are established on all major Hawaiian islands: Hawaiʻi, Maui, Oʻahu, Kauaʻi, and Molokaʻi. They are largely absent from the smaller, drier islands of Lānaʻi and Kahoʻolawe, where eradication efforts have proven successful. The pigs thrive in environments that offer dense cover and consistent moisture, supporting their omnivorous diet. Their preferred habitats are the mesic and wet forests, particularly in high-elevation areas. These environments provide an abundance of food sources, including native invertebrates, roots, and the fruits of invasive plants. The pigs’ ability to forage effectively in these remote, rugged landscapes allows them to proliferate in areas that are difficult for humans to access for control measures.
Ecological and Agricultural Damage
Ecological Damage
The foraging behavior of feral pigs is highly destructive, making them a primary driver of ecological decline in native ecosystems. When rooting for food, the pigs turn over the forest floor, destroying ground cover and causing severe soil erosion. This disturbance allows invasive, non-native plants to establish themselves, outcompeting native flora. The damage extends to marine environments, as heavy rainfall washes the disturbed soil and sediment into streams and rivers. This sediment runoff smothers nearshore coral reefs, blocking sunlight and reducing the reefs’ ability to recover from other stressors. Furthermore, the pigs create water-filled depressions, or wallows, which collect standing water and create breeding grounds for mosquitoes that transmit avian malaria. This disease is a major factor in the decline of native forest birds, such as the Hawaiian honeycreepers.
Agricultural Damage
In agricultural areas, the pigs’ appetites and destructive habits lead to significant financial losses for farmers. They frequently target traditional crops like taro (kalo) and sweet potatoes, consuming or trampling entire patches. Feral pigs also damage critical infrastructure, including irrigation lines and fences. This requires costly repairs and increases operational challenges for farming communities.
Management, Hunting, and Cultural Significance
Managing the feral pig population requires a comprehensive approach that balances ecological necessity with cultural practices. Common control methods include trapping, regulated hunting, and the construction of exclusion fencing. Large-scale fencing, often constructed of heavy-duty hog wire, is used to protect sensitive ecological areas, such as native forest reserves. Trapping typically involves the use of large corral traps, which are baited to capture multiple animals at once, or smaller box traps for individual pigs. Hunting remains a widely practiced and culturally important form of population control, with regulated seasons established by the state. Despite the pigs being an invasive pest, the pua’a holds deep traditional significance. Pig hunting is a valued cultural practice for subsistence and recreation, and the meat is a staple in traditional feasts like the luau.