Music with all its complexity seems like a uniquely human phenomenon. For instance, humans are one of the very few species that can detect a beat in music and clearly the only species to incorporate music so vastly into our lives. However, this does not mean that only humans produce sound that can to some extent be characterized as music. Investigation of animal “musicality” is a fascinating endeavor that could take us closer to understanding the evolutionary origins of music.
The first example of another species that is musical similar to humans is the bird. Songbirds have been studied extensively and seem to be vocal learners just like humans. Being a vocal learner means that the bird is able to learn new vocalizations from other members of its species, or in some cases, its surroundings. Take a look at this popular video of an astute vocal learner, the lyre bird, who has acquired an impressive repertoire of songs from its environment, including some sounds made by humans.
Songbirds seem to learn new vocalizations in the same way as humans learn language, by listening and imitating. This connection and the neural substrates underlying this phenomenon are discussed in an interesting article by Eerich Jarvis, published in 2004. A recent study by Andreas Pfenning, Erich Jarvis, and colleagues, published last year in the journal Science, revealed that the neural circuits in humans and songbirds that are important for vocal learning share convergent molecular changes of multiple genes. This means that though these species are very distant and different from each other in many respects, they independently evolved similar neural circuits and genetic characteristics related to vocal learning, song, and speech. Findings like this may in time help us understand how song and speech evolved.
Alongside humans, songbirds, parrots, and hummingbirds, other species like whales, dolphins, seals, sea lions, bats, and elephants, have also been long known to be able to learn new vocalizations. Recently, studies have also been published on the vocalizations of mice and giraffes, opening up new perspectives on animal “musicality”.
Rats and mice may not be vocal learners (however, see the discussion in this article), but in any case have been found to use song-like vocalizations for communication. A recent study found that the songs of male mice become more complex if there are signs in the environment that females are near, and that females prefer these complex songs to the simple ones. The mouse’s song is ultrasonic and has been processed to be audible to the human ear. As a side-note on murine vocalizations, did you know that rats also giggle when tickled ?
A study published in September explores the fascinating topic of nocturnal humming of giraffes. Yes, it seems that giraffes tend to hum at night. In this study, scientists report investigating 974 hours of recordings of giraffe vocalizations from zoos - an endeavor the researchers reported to be “as expected...time consuming, tedious and very challenging”. In addition to the typical snorts and grunts that giraffes make, the researchers discovered something new: a steady, harmonic humming that appeared only during nighttime. The researchers speculate that the hum is intended as communication, and the content of the message is the giraffe informing others about herself.
The musical behavior of humans is clearly more complex than that of other animals. However, research shows that animals also display a wide variety of behaviors that could be described as musical, and there may still a lot we do not know about the secret musical lives of other animals. Investigating the neural circuits and common genetic mechanisms related to vocal learning can help us understand the origin of vocalizations like speech. In time, thorough investigation of musicality as a broader animal phenomenon will perhaps help us come closer to understanding why and how something as powerful as music evolved.