A reference collection of the acoustic signals of male Nyctixalusmargaritifer Boulenger, 1882 (Anura: Rhacophoridae)

Nyctixalus margaritifer was initially documented in 1882 in the East Indies. However, the first and only-acoustic signal within the genus Nyctixalus to be recorded and classified was from Nyctixalus pictus. As part of-an effort to establish a reference collection, this study aims to investigate the acoustic characteristics exhibited-by N. margaritifer. The findings revealed that male calls were organised in note groups, which were arranged-in different series. Additionally, the notes showed characteristics of an unpulsed, sparse spectrum and consisted-of numerous harmonics. This fundamental note type had fast/shorter calls and was present in every note group. In certain conditions, male frogs emitted notes that were longer and slower compared to the fundamental note-type. These notes were found to be the first (introductory) or last in a group of notes. In some species, the first-(introductory) note of a call is commonly associated with chorus territorialisation, social behaviour, and enhanced-information transmission. However, the significance of the last note in calls/note groups remains unknown. The-results also indicate that male frogs consistently maintained their notes either with modulated or non-modulated-dominant frequency, or both. Nevertheless, further research is essential to uncover the mechanisms and anomalies-within the acoustic signals of N. margaritifer, particularly for taxonomy purposes.