The Pill Bug's Optimal Living Environment

The Pill Bug’s Optimal Living Environment

Abstract:

            In this lab, we observed the change in behavior of 10 pill bugs, when they were placed into a black and white environment. We experimented with the pill bugs preference for colors. We did so by placing a dry white paper into one dish of the choice chamber (two connected dishes) and a dry black paper in the other dish. We placed the 10 pill bugs into the dish and covered them. We removed the other choice chamber every 30 seconds to observe the pill bugs behavior and their preference for colors. We found that the majority of the pill bugs preferred a dark environment over a white one.

 

Question:

            How do the pill bugs react to changes in its environment?

 

Background:

            Behavior is the way an organism behaves or acts. Proximate questions about behavior are questions that focus on the physical mechanics of the behavior and the environmental factors that trigger a behavior (“how” questions). Ultimate questions are questions that focus on how evolution has created the behavior (“why” questions). An example of a proximate question is how does a bird know when it is the right time to sing? An example of an ultimate question is why does the bird sing?

Fixed action patterns are an innate behavior (unlearned and developmentally fixed behavior), a sequence of unlearned and mostly unchangeable acts triggered by sign stimuli. An example of a fixed action pattern is migration and the waggle dance.

 Imprinting is a mix of learned and innate behavior, it is limited to a certain sensitive period of an organism’s life. An example of imprinting is when a goose after hatching follow its mother. The young geese adapt to the environment where its mother goes and also the movement of its mother. The geese do what its mother does. The proximate cause would be, during the early and important developmental period, young geese observe their mother moves and calling. The ultimate cause would be, the geese who follow their mother will acquire the necessary skills for survival than those who do not follow their mother.

There are two types of innate behavior: kinesis and taxis. Kinesis behavior is a simple change in behavior in response to stimuli. An example of kinesis behavior is a sow bug that moves from a dry open area to a more preferable moist site under a leaf. Taxis behavior is an automatic movement from or to a stimuli. An example of taxis behavior is a trout fish will move against the direction of the current because most of the food comes in that direction.

Kinesis Behavior

 

Taxis Behavior

Classical and operant conditioning are two important concepts of behavioral psychology that lead to learning by different processes. Classical conditioning was first described by Ivan Pavlov, a Russian psychologist. The classical conditioning shows automatic and involuntary behavior that results from placing neutral signals before a reflex. In an experiment, Ivan Pavlov would play music when he would feed the dogs, he did so for a period of time. Than when the music was played without the food the dogs began to salivate because they were expecting food. The music in this case would be the conditioned stimulus, the salivating would be the condition response, and the food would be the unconditioned response.

Classical Conditioning

Operant conditioning was first described by B.F. Skinner, an American psychologist. Operant conditioning includes reinforcement or punishment after a behavior which leads to strengthening or weakening of voluntary behavior. An example is rewarding a dog through praise for a behavior such as fetching a ball, when the dog fails to retrieve the ball withhold the praise. Eventually the dog forms a relation between the behavior and the wanted reward.

Operant Conditioning

 

Hypothesis:

            If 10 pill bugs are placed into a choice chamber, one dish with white, dry paper (control) and another dish with black, dry paper (control), then the pill bugs will prefer the darker environment because their natural habitat (underneath rocks) is a dark environment.

            The controls are the dry paper of the same size, and the choice chambers. The dependent variable would be the number of pill bugs that prefer the dark environment and the number of pill bugs that prefer the light environment.  The independent variable would be time.

 

Materials:

·         2 choice chambers

·         10 pill bugs

·         1 circular dry white paper

·         1 circular dry black paper

·         1 paint brushes

·         1 timer

·         1 data sheet

 

Procedure:

1.      Find and Collect 10 pill bugs

2.      Place pill bugs into a choice chamber

3.      In another choice chamber, in one dish place a dry circular black paper and in the other dish place a dry circular white paper

4.      Gently place the pill bugs into the new chamber by using a paint brush

5.      Cover the new chamber with the old choice chamber

6.      Every 30 seconds remove the cover chamber and record your data

7.      And repeat step 6 for 5 minutes

 

 

Results:

 Black Paper and White Paper columns' units are number of pill bugs

 

  Orange line: white paper

                                                           Blue line: black paper

 

Conclusion:

            Our hypothesis is correct since the data shows that the majority of pill bugs moved to the darker paper rather than the white paper, because the darker paper resembles their natural habitat (underneath rocks) where we found and collected them. In nature the darker environment was protection from predators because the pill bugs could camouflage into the environment and hide from predators, this adaptation was developed through evolution. The constants of this lab was the dry environment and the choice chambers. One potential source of error is incorrectly recording your data by mixing columns. Another source of error would be not giving enough time for the pill bugs to move and choose the color they prefer.

Citations:

Cherry, Kendra. "Classical vs Operant Conditioning." About.com Psychology. N.p., n.d. Web. 01 Apr. 2014. <http://psychology.about.com/od/behavioralpsychology/a/classical-vs-operant-conditioning.htm>.

 

"Imprinting." - Definition from Biology-Online.org. N.p., n.d. Web. 03 Apr. 2014. <http://www.biology-online.org/dictionary/Imprinting>.

 

"Quizlet." Chapter 51: Study Questions~Behavioral Ecology Flashcards. N.p., n.d. Web. 03 Apr. 2014. <http://quizlet.com/16596812/chapter-51-study-questionsbehavioral-ecology-flash-cards/>.