On March 11, 1967, the palila was listed as an endangered species under the Endangered Species Act. In 1975, it was estimated that only 1,614 palila existed. In 1978, the 9th Circuit Court of Appeals ruled that feral sheep and goats had to be removed from critical habitat of the bird. From annual counts between 1980 and 1996, variable estimates of population ranged from 1,584 to 5,685 mature birds, though there are no consistent trends. In 1997, the west slope of Mauna Kea contained 72% of the population. The entire population, an estimated 4,396 birds, occupied an estimated .