Lauren K. Smith Richard J. Camp Seth Judge 2025 <p>In 2021, landbird surveys were conducted at Kalaupapa National Historical Park on the island of Molokaʻi to assess changes in species composition, distribution, and population densities since 2005. Point-transect distance sampling surveys were conducted on six transects at 50 landbird monitoring stations within an 1,834-hectare area. A total of nine landbird species were detected, with the ʻApapane (<i>Himatione sanguinea</i>) the only endemic Hawaiian species detected. Sufficient detections of six species allowed for population density and abundance estimates, which were compared to 2005 estimates using a two-sample z-test. The abundance of ʻApapane declined by 57% to 2,476 ± 729 (SE) birds in 2021 compared to 2005. Population densities of the House Finch (<i>Haemorhous mexicanus</i>), Japanese Bush Warbler (<i>Horornis diphone</i>), Warbling White-eye (<i>Zosterops japonicus</i>), and White-rumped Shama (<i>Copsychus malabaricus</i>) were also lower in 2021 than in 2005, but comparisons were inconclusive. Since 2005, the Red-billed Leiothrix (<i>Leiothrix lutea</i>) irrupted within the survey area to an estimated abundance of 11,088 ± 1,208 birds. The Warbling White-eye was the most abundant species, with an estimated 101,724 ± 11,692 birds. Surveyors failed to detect the Hawaiʻi ʻAmakihi (<i>Chlorodrepanis virens</i>), which has become increasingly rare on Molokaʻi. The federally threatened ʻIʻiwi (<i>Drepanis coccinea</i>) was last seen on Molokaʻi in 2010, further raising concerns about its potential extirpation. The Olomaʻo (<i>Myadestes lanaiensis</i>), an endemic thrush, has not been detected since 1980 and is likely extinct. These findings show the ongoing shift toward non-native bird communities and highlight the challenges of conserving native forest birds amidst widespread avian malaria transmission, introduced predators, and extensive habitat degradation. </p> application/pdf 10.36967/2313509 en National Park Service Pacific island landbird monitoring report, Kalaupapa National Historical Park, 2021 reports