A fascination with the melodic sounds emanating from humpback whales sparked bioacoustician Eduardo Mercado’s interest in their rhythmic and haunting songs. Contrary to the prevalent belief that these songs are mating calls, Mercado, a University at Buffalo psychology professor, speculated if the humpbacks were utilizing their songs for echolocation similar to toothed whales like dolphins. This curiosity led Mercado to delve into decades of research culminating in his latest book titled “Why Whales Sing.”
Whale songs differ from human or bird songs as they do not have distinct beginnings or endings. Baleen whales, including humpbacks, emit continuous sounds for hours, cycling through fixed patterns akin to an acoustic carousel without clear boundaries.
Mercado challenges the conventional notion that whales sing for courtship purposes, suggesting that their songs serve as a form of sophisticated echolocation rather than a performance for other whales. He notes that the evolution of sounds within whale songs over time and their resemblance to echolocation patterns observed in bats and distant echolocating animals reinforced his hypothesis.
While many scientists argue that whale songs are linked to courtship rituals due to the presence of mostly male singers in breeding contexts, Mercado’s research revealed a dynamic nature in whale sounds that defied the concept of consistent judgment criteria for other whales. This led him to investigate the possibility of whales using sonar capabilities to navigate their surroundings and communicate over vast distances.
Through a comprehensive study of whale sound physics and brain processing of sound variations, Mercado explored the extensive range of whale vocalizations. Humpback whale sounds can travel up to 10 kilometers underwater and be detected up to 100 kilometers away, showcasing their impressive sonar abilities.
Mercado emphasizes that whale sounds primarily target large moving objects, aiding whales in monitoring their surroundings, particularly other whales, in their nomadic and migratory lifestyles. The exploration of broad oceanic regions through sound scanning enables whales to maintain social connectivity despite their solitary nature when singing.
