Changes in Chagos Pygmy Blue Whale Inter-Call Intervals at Diego Garcia Island

This dataset is the result of an analysis of Chagos pygmy blue whale songs, recorded on hydrophones moored south of Diego Garcia Island in the central Indian Ocean. The hydrophones are part of the International Monitoring Network (IMS) operated by The Preparatory Commission for the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO). The measured quantity is the "Inter-Call Interval", the time from the start of one repetition of the song, to the start of the next. Also included in this dataset are the results of statistical trend fitting analyses, and the results of methodological validation tests including the Monte Carlo trial results on synthetic data, and a comparison of TDOA estimation methods. Raw data are provided as MATLAB '.mat' files, with select data products also provided as '.csv' and image files. The original audio data are not provided in this dataset and remain the property of the CTBTO. The CTBTO-IMS H08S audio dataset was obtained by T.L.R. and B.A.J. under a vDEC contract between the Preparatory Commission for the Comprehensive Nuclear-Test-Ban Treaty Organization and UNSW Sydney. The Provisional Technical Secretariat (PTS) of the Preparatory Commission gave access to the IMS data and is not responsible for the views of the authors. The authors thank the CTBTO for making their data available.