The Creepy Crawlies of the Music World

It may be hard to believe but  spiders do use sound and rhythm. The sounds that they use may be made with a little help from their surroundings but the sounds produced contribute to the life cycles of spiders (Rovner, 1967). One of the best examples from the arachnid world would have to be the Wolf Spider. The main use for these animals’ sounds is for hunting purposes (Rovner, 1967). Unlike most spiders, wolf spiders do not construct a web to entangle their pray in, instead they use the grassy fields which they live in to attract and capture prey (Rovner, 1967). They complete this process by rubbing their forelegs on the dry grasses, in combination with the sounds from their abdomen to attach the insects before restraining them and proceeding to eat them (Rovner, 1967). As well as being a valuable tool for survival, wolf spiders use a combination of these sounds to form a courtship sequence (Rovner, 1967).

 

The male wolf spider’s courtship sequence consists of several large bursts of pulses followed by the continuous sounds of pulses which will last about 2 seconds (Rovner, 1967). There is an increase in the volume of the sound toward the end of every train (Rovner, 1967). There is always a sudden end to the sequence and the intervals of the sequence are about 14 seconds (Rovner, 1967). Once the male has performed his part of the courtship sequence , if there are any receptive females in the region they will respond (Rovner, 1967). They do this by completing a leg waving display within 5 seconds after the male finishes his courtship sequence (Rovner, 1967). The female completes this leg waving in the intervals of the males sequence, as the males sequence intensifies so does the female’s (Rovner, 1967). As well as this courtship rhythmic dance the males use their palpal drumming sounds to complete a threat display (Rovner, 1967). 

This threat display performed by the males is generally completed at a male to male encounter (Rovner, 1967). Although the drumming sounds in this sequence slightly differ from that of the courtship sounds. In this display the sounds come in quick, frequent bursts of drumming sounds occurring at irregular intervals (Rovner, 1967). Although the world of a wolf spider seems so quiet, in actual fact there are many different sounds and rhythms are involved.  

Works Cited

Rovner, J., 1967. Acoustic communication in a lycosid spider. Animal Behaviour , Volume 15, pp. 273-281.

Images sources from

http://en.wikipedia.org/wiki/Wolf_spider

Video source from

https://www.youtube.com/watch?v=l7WEaZ14G-Q

The smallest Orchestra Member

Although little, the Brazilian cicada makes up for its size with the loud sounds that emerges from its little body. The male cicada’s produces songs which are made up of a series of clicks (Aidley, 1969). These clicks are produced by the collapsing of two very special regions of their body called the cuticle and the tymbals (Aidley, 1969). Both of these regions are located in the first segment of the abdomen (Aidley, 1969). The collapsing of is achieved but the contraction of two muscles on the tymbals (Aidley, 1969). One contraction of this muscle creates two clicks; an in click when the tymbals are pulled in and an out click when the tymbal is returned to its original position (Aidley, 1969).  The Brazilian Cicada has 4 different type of songs; the continuous song, the ‘zeep’ call, the distress call and the induced song (Aidley, 1969). The continuous song is a uninterrupted sequence of clicks for up to 20 seconds made by a undisturbed insect in their natural environment (Aidley, 1969).The ‘zeep’ call is a train of clicks lasting about half a second, repeated at intervals of 3-4 seconds (Aidley, 1969). This call is produced by undisturbed animals in their natural surroundings (Aidley, 1969). The next call, the distress call is a sequence of loud clicks interrupted often at intervals of 30 milliseconds (Aidley, 1969). This call is produced by disturbed animals upon capture or in response to pinching (Aidley, 1969). The final call, the induced song is caused when the insect is pinned down onto a cork board in the lab or it can be stimulated naturally (Aidley, 1969). There is no set click sequence or rate as it is different every time (Aidley, 1969). For this organism there is a call or sound for every occasion.

Bibliography

Aidley, D., 1969. Sound Produuction in a Brazilian Cicada. Experimental biology , Volume 51, pp. 325-337.

Small Critters with a Loud Voice

Although they are one of the smallest groups of organisms, that does not stop insects from making their presence known. Everyone by now would have spent at least one sleepless night because a tiny guest kept you awake with their music in your room. Well, scientists believe that insects have been causing humans sleepless nights at least as far back as Aristotle’s time (Alexander, 2000). Insects have the ability to make their sound by using various body parts in a couple of different ways (Alexander, 2000). Some insects use their entire bodies to rub against another individual’s body (Alexander, 2000). Others strike body parts such as their feet, tip of the abdomen or head against the ground. While others vibrate certain body parts such as their wings (Alexander, 2000). Most of the time these body parts consist of a special organ called tympanal organ or the body part is lined with hair called sensilla (Alexander, 2000). Scientific studies have shown that these organisms general only make sound for two reasons; when they are in a group or as a result of the presence or activities of another organism (Alexander, 2000). Within this large group there are a couple of very interesting examples of the sounds made in the animal world.

Bibliography

Alexander, R., 2000. Sound Production and Associated Behaviour in Insects. colombus , 57(10), pp. 101-113.

The Nosie of The Animal Kingdom

The animal kingdom is no quiet place; it is full of music and rhythm. These elements have evolved through the entire animal world. Especially in humans, music is intertwined with the evolution of social structure, group function and cultural behaviors (L. Wallin.et al, 2000). The progression of music and rhythm into the animal kingdom has allowed for the creation of behaviors such as the hominid vocal tract, symbolic gestures, acoustic communication and parent- infant communication (L. Wallin. et al, 2000). One of the easiest examples would be to look at ourselves, humans, and see how rhythm and music is used and how it affects our daily lives. Over the next couple of week I will be showing you the many ways that music and rhythm have evolved into the animal kingdom.

 
Tasmyn Menzies

wallin, L., 2000. An Introduction to Evolutionary Musicology. In: S. Brown, ed. The Origin Music. United States of America: Massachusetts, pp. 3-6.

  http://books.google.com.au/books?hl=en&lr=&id=vYQEakqM4I0C&oi=fnd&pg=PR9&dq=music+and+rhythm+in+the+animal+world&ots=i2d_y-erjS&sig=AsqakpZCaXXOjbAs1NlIaB-ljS4#v=onepage&q=music%20and%20rhythm%20in%20the%20animal%20world&f=false