The dataset consists of 14 spectrograms of humpback whale (Megaptera novaeangliae) vocalisations. These were created from 29-minute-long recordings off Bermuda using three separate deployments of Autonomous Multichannel Acoustic Recorders G3. Two hydrophones were deployed on Challenger Bank, from 31 March to 6 September 2018 and from 10 September 2018 to 23 April 2019. The third hydrophone was deployed at Sally Tuckers on the Bermuda Platform from 31 March to 10 September 2018. Vocalisations were visualised and analysed as spectrograms (fast Fourier transformation size: 2048 points, 75% overlap, sample rate = 16000 Hz, Hann window, frequency resolution: 7.8 Hz, time resolution: 32 ms), produced using Raven Pro 1.6 sound analysis software. Six of the 14 spectrograms in the dataset illustrate the first and last times that humpback whales were acoustically detected during each deployment. The four spectrograms from Challenger Bank are from the first deployment date (31 March 2018), 18 May 2018, 26 December 2018 and the recovery date 23 April 2019. The spectrograms from Sally Tuckers are from the deployment date (31 March 2018) and 19 May 2018. A seventh spectrogram illustrates an anomalous occurrence of a humpback whale vocalisation outside the normal singing season, recorded on Challenger Bank on 31 August 2018. The remaining seven spectrograms illustrate the humpback whale song structure encountered in spring 2018 on Challenger Bank. These were recorded on 6, 13, 20 and 27 April 2018, and on 3, 11 and 18 May 2018. The dataset allows users to acoustically verify the presence of humpback whales in Bermuda's waters from late December to mid-May, but also to characterise and compare humpback whale song structure over time or elsewhere.
