Singing humpback whales Megaptera novaeangliae favor specific frequency bands

Abstract

Many species alter their acoustic signals in response to environmental or anthropogenic factors. Differential use of frequency bands may occur as a result of overlapping biotic and abiotic sounds that interfere with communication signals between conspecifics. Singing humpback whales produce units with frequencies ranging from 30 Hz to over 10,000 Hz, but may favor specific frequency bands during song production. We tested the prediction that singing humpback whales consistently produce units with energy focused in specific spectral bands by measuring the consistency of peak frequency bands in the southeastern Pacific stock G population of humpback whales in the Gulf of Tribuga, Colombian Pacific. Songs recorded from 2013-2016 in the Gulf of Tribuga, Colombian Pacific suggest that not only do singers favor specific frequencies, but that they consistently concentrate their sound production within three frequency bands across years. One band spanning frequencies between 250-475 Hz is the most stable and consistently used band. These findings will allow for further spatial and temporal comparisons across distinct population segments, and can be used in future studies to assess whether singers change their use of frequency bands in response to increased anthropogenic noise or as themes evolve over time.Many species alter their acoustic signals in response to environmental or anthropogenic factors. Differential use of frequency bands may occur as a result of overlapping biotic and abiotic sounds that interfere with communication signals between conspecifics. Singing humpback whales produce units with frequencies ranging from 30 Hz to over 10,000 Hz, but may favor specific frequency bands during song production. We tested the prediction that singing humpback whales consistently produce units with energy focused in specific spectral bands by measuring the consistency of peak frequency bands in the southeastern Pacific stock G population of humpback whales in the Gulf of Tribuga, Colombian Pacific. Songs recorded from 2013-2016 in the Gulf of Tribuga, Colombian Pacific suggest that not only do singers favor specific frequencies, but that they consistently concentrate their sound production within three frequency bands across years. One band spanning frequencies between 250-475 Hz is the most stable and cons...