By Oscar Aranda – Biologist • Vallarta Nature Org. • December, 2012
Every winter, humpback whales offer us unforgettable experiences. But outside of those little moments when we observe a sea of dark secrets surrounding them, while they spend their lives underwater, humans try to understand. One of the most enigmatic secrets is in their songs, which intrigue us even today.
Complex songs, complex messages
The song of the whales began to be studied in the 70’s, discovered that humpback whales produced the longest and most complex series of sounds that exist in the animal world, after humans. Besides being powerful high and low frequency sounds that are produced by complex movements of air inside their bodies with no need to release a single bubble of air and without vocal cords.
Their songs are closely related to mating, since only males sing and do so during whale breeding season. It is common refer to them as a “love song”, when it is actually a “declaration of war” aimed at other males in the area (their potential rivals) to mark their territory and warn them about their presence.
Evolution has endowed the whales with one of the most sensitive ears of the animal world, being able to recognize the exact location and distance of other whales hundreds of miles away just by listening. Thus, the whale population can keep in touch through the water 4 times faster than in air.
Unfortunately, this great ability to perceive the sounds also put them at serious risk due to the drastic increase in ocean noise generated by increasingly intense human activities.
Living in a sea of noise
The sounds of whales help them navigate during migration, using their ears as their most important sense, since every location in the ocean world has its own natural and unique sounds. Unfortunately, human activities at sea have increased so much that scientists have now discovered that the sounds of whales are now reduced to drastically shorter distances, isolating populations with largely unknown consequences for them in the future. Scientists estimate that 20 years ago, some sounds produced by whales could travel over 1,000 miles (1,600 Km), however today they cannot hear more than 250 miles (400 Km).
A song in progress
The whale songs are sequences of sounds in organized and well-structured sentences that change through the song, which lasts about 10 minutes or more. This song is repeated continuously, and all males, who visit our bay, sing the same song. It´s like a rule that allows them to compete on equal terms, where “style” can make the difference between one singer and another, varying little by little, every year until it gradually evolves into in a new song that is constantly evolving.
Interestingly, among the variety of sounds that whales can produce, the sounds they make may remind us of a concert of farm animals such as cows, sheep, cats or dogs. This season, whaler-watchers have surprised us with the latest sounds that now seem “fashionable” this season made by all the whales. It is a complex sound that is at times is reminiscent of an elephant and at others, although you may find it hard to believe, includes sound like those produced by an electronic keyboard, which has drawn in tourists who hear it ask if it really is a whale song or a recording.
All whale-watching boats generate noise that may disturb the whales. Depends on them if we can see them or not. The fact that the whales keep coming year after year to our bay is no guarantee that they will continue to do so and if we continue harassing them and hunting them, surely this punishment will deprive us of this wonderful and unique spectacle that is whale watching. Help us to keep them close by making sure to use an authorized whale-watching vessel, committed to the primary goal of offering a tour that is respectful and responsible towards the whales and their environment.
Don’t forget that officially the whale-watching season ends this March 23rd and it’s not allowed continuing doing this activity after this day. Take advantage of this last days and enjoy this natural concert.
Oscar Aranda – Biologist
Oscar Aranda is the founder of the Western Ecological Society (Sociedad Ecologica de Occidente) and its program of protection and conservation of sea turtles in Puerto Vallarta. Visit his website www.vallartanature.org or e-mail him to email@example.com. If you love ecotourism, hire an eco-friendly whale-watching tour. Visit www.ecotoursvallarta.com or call (322) 22-26606.