Rousserolle de Saipan Acrocephalus hiwae

A relatively large plain brown reed warbler with a pale throat, a yellowish face, a darker cap and tail, and an absurdly long decurved bill. Found in areas of tall dense grasses, reed marshes, and scrubby thickets up to 400 meters of elevation. Song is a slow, loud reel of whistles, warbles, harsh “chak” notes, and trills. Call is a loud, offensive “tchak.” Often sings at night.