An overview of birds of Hawaiʻi is here: https://en.wikipedia.org/wiki/Category:Birds_of_Hawaii. Hawaiʻi’s birdlife, past and present, is legendary and tragic. It provides a stunning example of adaptive radiation for forest birds. Wikipedia’s list of all birds seen in Hawaiʻi, which they state as from Robert L. and Peter Pyle of the Bishop Museum, is here: https://en.wikipedia.org/wiki/List_of_birds_of_Hawaii.
The Wikipedia page provides a list of birds: “This list of birds of Hawaiʻi is a comprehensive listing of all the bird species seen naturally in the U.S. state of Hawaiʻi as determined by Robert L. and Peter Pyle of the Bishop Museum, Honolulu.
From the Wikipedia page: “The scope of this list encompasses the entire Hawaiian Islands chain, from Kure Atoll in the Northwestern Hawaiian Islands to the north, to the “Big Island” of Hawaiʻi to the south. The list contains 338 species. Of them, 64 are or were endemic to the islands, 130 are vagrants and 53 were introduced by humans. Thirty-three of the 64 endemic species are extinct and two formerly established introduced species were extirpated.” In addition to these totals, A. Ziegler in his 2002 book Hawaiian Natural History, Ecology, and Evolution notes a total of 46 taxa of birds that are prehistorically extinct in the islands.
For the report on The Birds of the Hawaiian Islands: Occurrence, History, Distribution, and Status, Version 2 – 1 January 2017, go here: http://hbs.bishopmuseum.org/birds/rlp-monograph/. This website also has a great list of resources to consult on Hawaiʻi birds.
Lists, naming conventions, and descriptions are available in the document The Birds of the Hawaiian Islands: Occurrence, History, Distribution, and Status, Version 2 – 1 January 2017. Robert L. Pyle and Peter Pyle: http://hbs.bishopmuseum.org/birds/rlp-monograph/Default.htm. On that page the Primary Checklist includes links to species accounts, most with photos: http://hbs.bishopmuseum.org/birds/rlp-monograph/PrimaryChecklist.htm
The Hawaiʻi Audubon Society website has a link to their Elepaio Journal with many papers and articles of interest on Hawaiʻi birds: http://www.hawaiiaudubon.org/
Endemic species in Hawaiʻi are listed with some descriptions on a Wikipedia page. The pages states there are 71 but the list given has 75: https://en.wikipedia.org/wiki/Endemic_birds_of_Hawaii. For the History of Endemic Bird series by W.E. Banko (1979-1990) start here: https://scholarspace.manoa.hawaii.edu/handle/10125/318/browse?type=dateissued&sort_by=3&order=DESC
Brief descriptions with some information specific to Maui: https://eastmauiwatershed.org/explore-the-watershed/gallery/photos/bird-gallery/
Historical accounts and beautiful paintings of Hawaiʻi’s birds are in the book Aves Hawaiʻienses published in the late 1800s. The full book is available at: https://archive.org/details/AvesHawaiienses00Wils/page/n8
The American Bird Conservancy, Hawaiʻi Program website has information on challenges for conservation in the state and about their specific projects: https://abcbirds.org/program/hawaii/. They summarize the sad history of post-human discovery of the islands for Hawaiian birds – “Since humans arrived, 95 of 142 bird species found nowhere else have become extinct on Hawai’i. Thirty-three of Hawai‘i’s remaining 44 endemic birds are listed under the Endangered Species Act; 11 of those have not been seen for decades and are likely extinct.”
A. Ziegler in his 2002 book Hawaiian Natural History, Ecology, and Evolution provides the following numbers for avian founder species (numbers represent estimated endemic species ancestors plus indigenous species, but not including migrant shorebirds): 20+6=26.
Here are some native Hawaiian birds you can still readily see with a little effort: https://www.audubon.org/news/hawaii-counts-meet-10-island-birds-now-eligible-your-life-list.