Kauai Akialoa

The Kauaʻi ʻakialoa is an extinct species of Hawaiian honeycreeper in the subfamily Carduelinae of the family Fringillidae. It was endemic to the island of Kauaʻi, Hawaii, and became extinct in the 20th century due to introduced avian disease and habitat loss. The Kauaʻi ʻakialoa was about seven and a half inches in length and had a very long downcurved bill, which covered one third of its length. The adult males were bright olive-yellow on top and yellow on the bottom. The throat, breast, and sides of the body were olive-yellow. The females, however, were green-gray above and had a shorter bill.

Source: Wikipedia