Only male fin whales sing loud songs

Abstract
The low-frequency vocalizations of fin and blue whales are the most powerful and ubiquitous biological sounds in the ocean1,2. Here we combine acoustic localization and molecular techniques to show that, in fin whales, only males produce these vocalizations. This finding indicates that they may function as male breeding displays, and will help to focus concern on the impact of human-generated low-frequency sounds on recovering whale populations.