Cicadas make noise primarily as a mating call. The loud, distinctive sound produced by cicadas is generated by males to attract females. This noise, often referred to as “singing,” is created by specialised structures called tymbals located on the sides of the cicada’s abdominal region.
a male cicada contracts its tymbal muscles, these membranes buckle inward, producing a clicking sound. Rapid repetition of these clicks creates the characteristic buzzing or droning noise that can be heard during cicada emergence periods.
The sound production mechanism is highly efficient, allowing cicadas to produce very loud noises despite their relatively small size. Some species can produce sounds exceeding 100 decibels, which is comparable to the noise level of a motorcycle. The volume and persistence of the sound are crucial for male cicadas, as it helps them compete with other males and increases their chances of being heard by potential mates.
Different species of cicadas have distinct songs, which serve not only to attract females of the same species but also to minimise confusion and hybridisation between species. This specificity in their calls ensures that mating occurs correctly, maintaining the genetic integrity of the species.
Cicada songs can also serve to establish territory and ward off rival males. By marking their presence with sound, male cicadas can reduce the likelihood of confrontations and establish dominance within a given area.
The periodical emergence of cicadas, which can be every 13 or 17 years for some species, adds to the impact of their noise. During these periods, large numbers of cicadas emerge simultaneously, creating a cacophony that can be overwhelming in certain regions. This synchronous emergence is thought to overwhelm predators, ensuring that enough individuals survive to reproduce.
In summary, cicadas make noise primarily for reproductive purposes. The loud and distinctive sounds produced by male cicadas attract females, establish territory, and reduce predation risks through sheer numbers during their periodical emergences. The unique mechanisms and behaviours associated with cicada sound production are fascinating adaptations that have evolved to maximise their reproductive success.
Feature image “Cicada” by YoungSue is marked with Public Domain Mark 1.0.