Kauaʻi ʻōʻō

The native Hawaiians named the bird ʻōʻō ʻāʻā, from the Hawaiian word ʻōʻō, an onomatopoeic descriptor from the sound of their call, and ʻāʻā, meaning dwarf.^[9]

 

This bird was among the smallest of the Hawaiian ʻōʻōs, if not the smallest species, at just over 20 centimetres (8 in) in length.^[9] The head, wings, and tail were black. The rest of the upperparts were slaty brown, becoming rufous on the rump and flanks. The throat and breast was black with white barring, which was particularly prominent in females. The central tail feathers were long, and there was a small tuft of gray feathers under the base of the wing. While the beak and legs were black, the leg feathers were a rich golden yellow. It was the only ʻōʻō known to have eyes with yellow irises. Like other honeyeaters it had a sharp, slightly curved bill for sampling nectar. Its favored nectar sources were Lobelia species and the ʻohiʻa lehua tree. This species was additionally observed foraging in lapalapa trees. It also ate small invertebrates and fruit. The Kauaʻi ʻōʻō was very vocal, making hollow, erratic, flute-like calls. Both the males and females were known to sing.

 

The bird was a cavity nester in the thickly forested canyons of Kauaʻi. All of its relatives have also become extinct, such as the Hawaiʻi ʻōʻō, Bishop's ʻōʻō, and Oʻahu ʻōʻō. Relatively little is known about these extinct birds. The species became extinct from a large range of problems, including mosquito-transmitted diseases (which caused the species to retreat to higher ground, ultimately retreating to high-altitude montane forests in the Alakaʻi Wilderness Preserve), introduction of mammalian predators, and deforestation.^[10] Higher elevation forests lack tree cavities, so few, if any, nests could be made. As of the early 1960s, the bird had an estimated population of about 34 living individuals. In the 1970s, the only known footage of the bird was filmed by John L. Sincock on Super 8 film and several song recordings were made as well (with Harold Douglas Pratt Jr. being one of the people involved in recording the songs).^[11] In 1981, a pair was found.

The final blows were two hurricanes, Iwa and Iniki, occurring within ten years of each other. They destroyed many of the old trees that still had cavities, and prohibited tree growth when the second one arrived, causing the species to disappear. As a result, the last female bird disappeared (likely killed by Hurricane Iwa). The male bird was last sighted in 1985, and the last sound recording was made in 1987 by David Boynton.^[12][13][14] After failed expeditions in 1989 and Hurricane Iniki in 1992, the species was declared extinct by the IUCN in 2000. It is still believed by some that the species may survive undetected, as it had already been proclaimed extinct twice: once in the 1940s (later rediscovered in 1960) and again from the late 1960s to the early 1970s, being rediscovered by the wildlife biologist John Sincock.^[15] However, it has a loud and distinctive call, and intensive surveys that occurred from 1989 to 2000 failed to find any. In 2021, the United States Fish and Wildlife Service proposed declaring it extinct. In October 2023, it was declared extinct and delisted from the Endangered Species Act.^[2]

• Lewis, Daniel (2018). Belonging on an Island: Birds, Extinction and Evolution in Hawaii. Yale University Press, New Haven, CT. ISBN 978-0-3002-2964-6.. Chapter 2 of the book is about the ʻōʻō, including the work of John Sincock, who rediscovered the bird in the early 1970s.
• Kauaʻi ʻōʻō
• ML: Macaulay Library Archived February 8, 2018, at the Wayback Machine
• 3D view of specimens RMNH 110.028 and RMNH 110.029 at Naturalis, Leiden (requires QuickTime browser plugin).^{[dead link]}
• "Kauaʻi ʻŌʻō" (PDF). Hawaii's Comprehensive Wildlife Conservation Strategy. State of Hawaiʻi. October 1, 2005. Archived from the original (PDF) on June 16, 2011.
• Call of Kauaʻi ʻōʻō; Cornell Lab of Ornithology, Macaulay library Kauai Oo Moho Braccatus ML6050 John L. Sincock, June 6, 1975 Alakai Swamp, Kauai Hawaii
• Banko, Winston E. (December 1981). History of endemic Hawaiian birds. Part I. Population histories – species accounts. Forest birds: 'Ō'ō, and Kioea (Report). CPSU-UH Avian History Report. Vol. 7B. pp. 175–185. hdl:10125/346.
• Sykes, P.W. Jr.; Kepler, A.K.; Kepler, C.B.; Scott, J.M. (2000). Kauai'i 'O'o. Birds of North America. Vol. 535. Washington, DC: American Ornithologists' Union. pp. 1–32.

• A recording of the bird's call. 1975
• Archive of Kauaʻi ʻōʻō footage and recordings on Macaulay Library