What will the effect of vibration have on earthworm behavior?

Background Research

• Earthworms are commonly found in moist soil around the world. “Earthworms contribute to the growth of plants, also help break down the humus.” (World book encyclopedia, 1983) Earthworm “bodies are about 70% protein; rich food for many predators. Their major enemies are insect eating birds, like robins, and mammals like moles. The robin's ears can actually hear the earthworm moving under ground.” (John Mertus, 1993)

• Earthworms can feel the vibrations of the predators or any animal on top of the soil, which allows them to escape quickly.

Introduction and Background Worm ‘grunting’ is a profitable business where earthworms are

harvested for fish bait. Collecting worms can generate substantial income, but collecting earthworms also can damage the earthworm population. One of the ways they collect earthworms is using vibration effects in the soil to surface earthworms. “In the southeastern USA, worm ‘grunting’ is commonly practiced to collect earthworms for fishing.

A common assumption is that vibrations cause the worms to surface, but this phenomenon has not been studied experimentally. Worm grunting is economically and ecologically important in localized regions.” (Mitra, Feb. 28, 2009)

• The purpose of this experiment was to determine what effect vibration has earthworm behavior.

• I predict that as the number of vibrations increase then the more earthworms will surface, because of their animal instincts to escape danger.

Experimental Design diagramHypothesis:As the number of vibrations increases, then the number of earthworms surfacing will also increase.

Independent Variable: number of vibrations

Dependent Variable: number of surfaces earthworms

Levels 5

Vibrations

10

Vibrations

15

Vibrations

20

Vibrations

25

Vibrations

Trials 5 5 5 5 5

-Materials -Procedures

1)   Put soil in each of the five containers to about ¾ of the total about of the containers (at least 1-½ inches of space from the top of the container).

2)   Place approximately 5 earthworms in each container (let them relax and dig underground)

3)   Place a wooden stake in each five containers avoid hitting any earthworms.

4)   Using the flat metal object, scrape the top of the wooden stake to recorded amount of scrapes (5, 10, 15,20, 25)

5)  Observe how many earthworms surface

6)   Record observations

        25 earthworms •         soil•         5 containers•         5 wooden stakes•         1 flat metal object

Data TableWhat will the effect of vibration have

on earthworm behavior?    Trials            

  Levels   Group 1: Group 2: Group 3: Group 4: Group 5: Average:

    5 0 0 1 0 1 0.4

10 0 2 0 1 1 0.8

    15 2 1 3 3 2 2.2

    20 4 3 3 2 3 3

    25 5 4 5 3 5 4.4

IV: number of vibrations

DV: number of earthworms surfaced

Data Analysis

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

reaction rate

5 10 15 20 25

Levels

what effect will vibrations have on earthworms?

trial average

The graph shows that as the number of vibrations increase, the amount of earthworm surfacing also increases.

Group 1

Group 2

Group 3

Group 4

Group 5

Conclusion

• The purpose of the experiment was to determine if vibrations effected earthworm behavior. The results show that as the number of vibrations increased, the appearance of earthworms on the surface also increase. The results shown also support the given hypothesis, which was “ If the amount of vibrations increase, then the amount of earthworms surfaced will also increase”.

• Earthworms can feel vibrations in the soil and animal instincts surge. The major enemy of the earthworm is the mole which digs under ground. Earthworms feel the vibrations and at first reaction, earthworms suspect the predator, the mole, is digging so therefore they dig their way to the surface to escape being captured by their predator.

Works Cited

• 1) Mertus, John. “Earthworms” Emirates Natural History Group. 1993. 28. Sept.

2010

<http://www.enhg.org/resources/articles/worms/worms.htm>

 

 

• 2) Mitra, O., Callaham Jr, M.A., Smith, M.L., Yack, J.E. “Grunting for worms:

seismic vibrations cause Diplocardia earthworms to emerge from the

soil” PubMed Central. 23 Feb.2009. 28 Sept. 2010

<http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2657739/>

• 3) “Earthworms”. World Book Encyclopedia. 1983.