From www.iucnredlist.org: It feeds on invertebrates, and has been observed excavating rotting wood from the centre of a twig, presumably for insect larvae. Both parents have been observed bringing food to the nest, with the male providing some food for the female. The species is threatened.
Note: this image is of the Hawaii Creeper. The previous is of the Kauai Creeper. Both are known as Akikiki. Next is the Maui Creeper, known as the Alauahio.
Marian Berger's paintings of the Hawaii Creeper can be found on my website at: Living Endemic, and the Marion Collection.
Image is copyrighted by Frederick Frohawk and Wellfleet Press.