Birdsong is certainly not an understudied phenomenon. While acoustic signalling is “not the most common mode of communication in animals,” it is one of the most studied by biologists. While the vast majority of studies have focused on “spectral parameters and temporal patterns” (the notes and rhythm) of birdsong, however, relatively few have looked at amplitude (volume) of the song. It might be obvious that louder birdsong can be heard over greater distances and can be detected more easily in noisy conditions, there are many other aspects of amplitude that have remained unstudied. Part of the reason for this is that accurately measuring amplitude is not a straightforward process. Distance, the position of the observer (or recorder) and air pressure may all affect measurements, to name just a few factors.

Acknowledging that gap in the literature (and the challenges inherent with studying amplitude), this study looked at the volume of birdsong and what louder or quieter volumes may be intended to communicate. Based on a thorough review of previous studies on the subject, the authors note that higher-volume birdsong is physically harder for birds to perform. In the case of males, this may lead to more social aggression and, as a result, it tends to be bigger and healthier birds that sing loudly because they can “bear the costs.” Louder songs seem to work better to attract mates, but may serve to attract rivals as well.

Interestingly, the researchers note that because of advancements in technology it is more and more possible to get clean and accurate measurements of birdsong in the wild, which eliminates the “need” for such research in a laboratory setting. This is worth noting for advocates of both wild animals and animals used in experiments given that it indicates that there are ways to conduct observational research on birds that does not involve keeping them in captivity.