When Captain James Cook anchored off Hawaii in January 1778, he wasn't planning an invasion. He brought his crew, gifts, and a few goats meant as a future food source for sailors and islanders. According to a National Parks Conservation Association feature, Cook visited Hawaii three times, and the first two visits were peaceful trade exchanges. The third ended in violence, and Cook died in the fighting.
Cook's crew released the first goats on Niʻihau on February 1, 1778, a ram and two ewes, and released more the following year at Kealakekua Bay on the Big Island. Captain George Vancouver releases another pair on Kauaʻi on March 13, 1792. According to the NPS historical report, these animals reproduced quickly once they went feral, and their descendants have never fully left the islands since.
Why Hawaii's plants never stood a chance
Hawaii's ecosystems evolved in near-total isolation, with no grazing ungulates present. According to the same NPS report, native plants in the park "had never before encountered mammal predators" and had "either lost, or never developed, adequate defenses such as thorns or an unpalatable taste." Goats also had no natural predators on the islands, so their numbers grew fast. According to the University of Hawaii ecological study, ‘The influence of feral goats on the lowland vegetation in Hawaii Volcanoes National Park,’ the park's coastal grasslands turned out to be entirely goat-altered landscapes. When scientists fenced goats out of test plots, native bunchgrasses and a rare native vine returned within two years, proving the bare terrain was a man-made, or rather goat-made, problem.
