Male humpback whales (Megaptera novaeangliae) produce complex, patterned songs that are traditionally recorded on their breeding grounds. In this work, we report results from the first continuous acoustic monitoring of a humpback whale feeding ground off southern Chile, Corcovado Gulf. Using an autonomous continuously recording system anchored to the seafloor and an automatic signal detector, we used the units within a song to analyze the temporal distribution and diel patterns of humpback whales. Acoustic recordings were made at the end of the austral summer and autumn of 2012. Songs occurred over the entire 130 d monitoring period, from 1 February to 15 June 2012. The percentage of units detected increased throughout the monitored period with the highest detections in the last recorded month (June), despite recording for fewer days that month. Furthermore, songs were detected during all light regimes studied, but most frequently during darkness