Yellow-bellied Greenbul

A medium-sized black tern with a tail that appears square or slightly forked. Smaller and darker than Brown Noddy with a shorter tail, thinner bill, and more contrasting white cap. Uniformly black back, wings and tail, and dark legs, except on the main Hawaiian islands where tail and rump are grayish and feet and legs are bright orange. Nests on coastal cliffs, in sea caves, and in trees. More often seen in groups than Brown Noddy. Often seen from shore.

An attractive thrush of moist foothill and montane coniferous and mixed forests. Favors areas with dense, shady understory and extensive ground cover. Combination of gray head, black wings, and orange back and belly is unique; most other large forest thrushes in its range are dark overall. Usually seen singly, but will occasionally forage in small groups. Song, as with many other thrushes, varies individually, but usually consists of short, breathy individual phrases, often whistled. Gives slick “tsk, tsk” in alarm, as well as hard rattling calls.

Medium-sized dark swift with small white throat patch and rump patch. Commonly nests in building and cave crevices and often seen in small flocks over valleys, cities, and forests. Plumage pattern is similar to Pacific Swift, which has darker throat and very different shape, with longer, more pointed wings and long, sharply forked tail. White plumage patches distinguish it from Aerodramus swiftlets. Gives a high-pitched, twittering trill.