The Lana'i Hookbill (Dysmorodrepanis munroi) was a species of finch in the Fringillidae family. It was endemic to the island of Lana'i, Hawaii. It was last seen in the Kaiholeua Valley and Waiakeakua area of the island. It became extinct due to habitat loss. G.C. Munro collected a single specimen of this species on the island of Lanai in 1913. No specimens have been seen and or collected since. The specimen is housed in the Bishop Museum in Honolulu.
Illustration by F.W. Frohawk.
Adults are light gray with a tinge of green, the underparts were paler and almost white. A light band ran along the wing and there was a light mark over the eye. The mandibles curved towards each other and so the tip of the lower mandible was the only part that touched the upper, therefore leaving a gap in the middle. The bird is about 6 inches long, and the weight is unknown.
The species has been seen in the wild only a few times ever, and all between 1912 and 1918 by Munro. Some naturalists consider that the Lana'i Hookbill was actually just a deformed individual of another species and because so few were ever seen (probably only three) there is some doubt as to the validity of these records. It was thought by some to be the same species as the O`u (Psittirostra psittacea), however, recent study by James et al., 1989 has shown that it is a valid species. Its preferred food is unknown because the birds were never seen feeding, though dissection of the stomach showed it had fed on native berries from the island. It has been speculated based on its uniquely shaped bill and relatively weak jaw muscles that it may have been a specialist feeder on snails. The extinction of local snails through human intervention could then have led to the reduction in numbers and ultimately, the extinction of this species. Munro first saw the bird on February 22, 1913, and collected the single specimen in the Kaiholena Valley of Lanai. Nearly everything known about the bird is in his book The Birds of Hawaii (1960). The only existing specimen (Munro's) is in Bishop Museum in Honolulu. After 1913, Munro saw the bird on March 16, 1916, in the Kaiholena Valley, and on August 12, 1918, at Waiakeakua. The 1918 sighting was the last, by that time most of the native akoko forest on Lanai had been replaced by pineapple plantations.