Kevin W. Brinck Adonia Henry Afsheen Siddiqi Rachel A. Rounds Jennifer Chutz Eben H. Paxton 2022 <p id="ID0EF" class="first">Four endemic species of wetland-dependent waterbirds occur on the main Hawaiian Islands, all of which have experienced sharp population declines and are listed as endangered species. Twice per year, state-wide surveys are conducted to count waterbirds, but these surveys are evaluated only infrequently. We used a state-space approach to evaluate long-term (1986–2016) and short-term (2006–2016) trends and current distribution and abundance of endemic Hawaiian waterbirds. The most numerous species was the Ae‘o, or Hawaiian Stilt (<i>Himantopus mexicanus knudseni</i>), with a 5-year estimated average abundance of 1,932 individuals, followed by ‘Alae Ke‘oke‘o, or Hawaiian Coot (<i>Fulica alai</i>), with 1,815 individuals, Alae ‘Ula, or Hawaiian Common Gallinule (<i>Gallinula galeata sandvicensis</i>) with 927 individuals, and the Koloa Maoli, or Hawaiian Duck (<i>Anas wyvilliana</i>) with 931 individuals. All four species had positive trends over the long-term, but short-term and island specific trends were more variable, and in some cases negative. These results provide valuable information to help guide management of Hawaii’s threatened and endangered endemic waterbirds.</p> application/pdf 10.1675/063.044.0404 en The Waterbird Society Distribution and trends of endemic Hawaiian waterbirds article