Background

The History of Invasive Ungulates in Hawaiʻi

Hawaiʻi’s unique island ecosystems evolved in isolation over millions of years, leading to the development of thousands of native plant and animal species found nowhere else on Earth. However, the introduction of non-native wildlife has severely disrupted this delicate balance. Invasive ungulates such as feral pigs, goats, sheep, deer, and cattle pose a serious threat to Hawaiʻi’s biodiversity, watersheds, agriculture, and cultural resources.

Ecology

Feral pigs root through forest floors, destroying native vegetation and creating ideal conditions for invasive plant growth. Their wallowing and digging also contribute to soil erosion, which degrades water quality and threatens coral reef systems downstream. Similarly, ungulates like goats and deer overgraze native plants, leaving large areas of land barren and unable to regenerate. This loss of native habitat puts many endangered species at even greater risk of extinction. Explore our Environmental Impacts tab for more species-specific information.

Society

Beyond environmental harm, invasive wildlife also impacts Hawaiian culture and livelihoods. Many native plants and animals have deep cultural significance, and their decline disrupts traditional practices and knowledge. In agriculture, feral animals damage crops and infrastructure, costing farmers millions annually. Addressing the spread and impact of invasive species is not only an environmental imperative, but a cultural and economic one as well, requiring coordinated efforts from government, communities, and land stewards across Hawaiʻi.