Cicadas are known for their distinctive, loud sounds that fill the air during warm months, especially in the summer. These insects, found across the world, have developed a unique form of communication through sound. Understanding what sound a cicada makes involves exploring the biology behind their calls, the different types of sounds, and the role these sounds play in their life cycle.
In this comprehensive guide, we’ll dive into the various cicada sounds, how they produce them, and why these sounds are essential to their survival and reproduction. Whether you’re hearing a cicada for the first time or are curious about the nuances of their communication, this article will provide a detailed explanation of cicada sounds and their significance in the natural world.
Introduction to Cicadas and Their Sounds
Cicadas are insects that belong to the order Hemiptera and the family Cicadidae. They are most known for their loud, buzzing or droning calls, which can often be heard in the summer months, especially during the daytime. There are over 3,000 species of cicadas worldwide, and while many of them make sounds, the most iconic are the ones found in temperate and tropical regions.
Unlike most insects, cicadas produce their sounds in a highly specialized manner, making their noise both a biological feature and a key part of their behavior. Their calls are often loud enough to be heard by humans, but the sounds themselves serve a vital purpose for cicadas in nature.
How Do Cicadas Make Sound?
Cicadas produce sound through a specialized body part called the tymbal. The tymbal is a membrane located on the sides of the abdomen, which cicadas can vibrate to create sound.
Here’s how the process works:
- Tymbals: Cicadas have two tymbals, one on each side of their abdomen. These membranes are stretched tightly and are capable of vibrating at very high speeds.
- Muscle Contraction: Cicadas have powerful muscles attached to these tymbals. When these muscles contract, the tymbals are pulled inward, creating a click or a snap.
- Resonance: The sound produced by the tymbal is amplified by the cicada’s hollow body, which acts as a resonance chamber. This amplification is what makes cicada calls so loud.
- Sound Production: By rapidly contracting and relaxing their muscles, cicadas create a rhythm of sound waves that form their distinct calls. The sound produced can vary in frequency, volume, and pattern depending on the species.
The sound production is a highly efficient process, allowing cicadas to produce calls that can reach over 100 decibels, making them one of the loudest insects on Earth.
Types of Sounds Cicadas Make
Cicadas are capable of producing several different types of sounds, each serving a distinct purpose. The most common sounds cicadas make include:
1. Calling Song
The calling song is the most well-known cicada sound. This song is produced by male cicadas and is used to attract females for mating. The sound is usually loud, continuous, and droning, often described as a buzzing or humming noise. The calling song can last anywhere from a few seconds to several minutes, depending on the species.
2. Courtship Song
Once a female cicada is attracted to a male, the male will often switch to a softer, more rapid courtship song. This sound is meant to communicate the male’s fitness and readiness to mate. The courtship song is generally quieter than the calling song and may involve more varied patterns.
3. Distress or Alarm Sound
Some cicadas can also produce an alarm sound when they feel threatened. This sound is usually much shorter and more erratic compared to the mating calls. It can act as a warning to other cicadas in the area or signal to predators that the cicada is not an easy target.
4. Static Sound
Some cicadas make a continuous, low-frequency sound that serves as a form of background noise, which is less distinct but can be heard in large groups. These sounds are usually made by individuals in a large swarm, contributing to the general buzz in the environment.
5. Tymbal Clicking
While this sound is more mechanical than musical, the rapid clicking of the tymbal can be heard when cicadas are not producing their full calling songs. These clicks can be very faint but serve as another form of communication between cicadas.
Why Do Cicadas Make Noise?
Cicadas make noise primarily for reproductive purposes, though the sounds also serve other roles in their life cycle. Here are the main reasons cicadas produce sound:
1. Attracting Mates
The most important reason male cicadas produce their calling songs is to attract females. The calling song signals the male’s presence and serves as a mating call. In some species, the volume and pitch of the song can indicate the male’s fitness, allowing females to select the best mate.
2. Establishing Territory
In some species, male cicadas use their calls to establish and defend territories. By calling loudly, a male cicada signals to other males that the area is occupied, reducing the chances of competing males encroaching on its space.
3. Communicating Alarm
When threatened, cicadas may produce distress calls to warn other members of the population. These calls alert other cicadas to take evasive actions or to remain hidden, reducing the risk of predation.
4. Species Identification
Cicadas rely on their sound to identify one another by species. The distinct calls are used to ensure that mating occurs only between individuals of the same species, helping to maintain the species’ integrity.
Cicada Sounds and Their Role in Mating
Mating is a central activity in the cicada life cycle, and sound plays an essential role in this process. The male cicada’s calling song is specifically designed to attract females. Here’s how the mating process unfolds:
- Calling Song Attraction: Male cicadas produce their loud calls to attract females. Females are usually attracted to the loudest or most consistent calls.
- Selection of Mate: Females choose their mates based on the sound quality, volume, and frequency. Males that produce louder or more sustained calls are often preferred, as these traits indicate strength and vitality.
- Courtship Behavior: Once a female is attracted, the male may switch to a quieter courtship song. If the female is receptive, mating follows.
The timing of cicada calls also plays a role in synchronizing mating behaviors. In certain species, cicadas emerge en masse at specific times of the year, and their calls are essential in coordinating mating activities.
The Impact of Cicada Sounds on the Environment
Cicada sounds serve more than just reproductive purposes. The acoustic environment created by cicadas has several ecological impacts:
1. Soundscape Contribution
The buzzing calls of cicadas contribute significantly to the soundscape of many natural habitats. In forests and fields, their sounds are a characteristic feature of summer ecosystems, adding to the overall biodiversity of the area.
2. Predator-Prey Dynamics
The loud calls of cicadas may serve as a defense mechanism against some predators, who are less likely to attack in areas with high cicada activity. Additionally, predators such as birds and reptiles rely on cicadas as a food source, creating a balance in the local ecosystem.
Common Misconceptions About Cicada Sounds
There are several misconceptions about cicada sounds that can confuse people. Let’s clear up some of the most common ones:
1. Cicadas Only Make Sound to Mate
While mating is a primary reason for sound production, cicadas also make noise for territorial defense and communication during distress. Their calls serve multiple ecological functions.
2. Cicadas Are Constantly Loud
While cicadas are known for their loud calls, not all species are equally noisy. The volume and frequency of their calls can vary widely depending on the species and environmental conditions.
3. Cicada Sounds Are Always Annoying
Though cicada sounds can be loud and repetitive, they are also a natural part of the ecosystem. For many people, the sounds are a sign of summer and are integral to the environment’s acoustic landscape.
Conclusion
Cicadas make sound for various important reasons, from attracting mates to defending territories and signaling alarm. The process of sound production, which involves specialized body structures like the tymbal, allows cicadas to communicate effectively within their species. Despite their reputation, cicada sounds play a crucial role in maintaining biodiversity and balance within ecosystems.
By understanding what sound cicadas make and why, we can gain a deeper appreciation for these fascinating insects and their vital role in the natural world. Whether you find their calls endearing or annoying, there’s no denying the significant impact cicadas have on the environment.