Gaul, W. B.; Lin, J.; Roark, E.

We investigated how detectability and vocalization patterns of Saipan Reed Warblers (Acrocephalus hiwae) varied by time of day. We used long-duration sound recordings from eleven locations occupied by Saipan Reed Warblers to model the probability of detecting a vocalization in each hour of the day. We found that Saipan Reed Warblers sang during all daylight hours. We did not find evidence of a dawn or evening chorus in this species. These results are useful for determining what time of day surveys of Saipan Reed Warblers should be conducted, which is particularly relevant because Saipan Reed Warblers are protected by local and U.S. Federal laws.