Lab 2: Animal Behavior

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Lab 2 Animal Behavior
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I. Background Reading

• From Textbook (Biology Concepts and Connections
  by Campbell et al., 2006)
• p 9-10 Scientific Method
• p 703-723 Animal behavior
• p 380-383 Arthropods

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II. Lab Two Objectives

• To observe and record the locomotor behavior of
  Porcellio scaber (sow bugs) in response to
  environmental stimuli.
• 2. To become familiar with the scientific method.
• 3. To write a scientific lab report in which you
  present your data on the behavior of sow bugs in
  the laboratory.

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III. Introduction to Animal Behavior

• One of the basic characteristics of life is the
  capacity for response to environmental change.
• Stimulus a change in the environment that
  triggers a response (reaction).
• example A cat approaching a bird.
• Behavior the repertoire of responses that
  characterizes an organism.
• example A bird flying off at the sight of a cat
  is an example of an escape behavior. The bird had
  a number of options (stay, hop, fly away) to
  choose from (a repertoire).

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III. Introduction to Animal Behavior (cont.)

• Two Categories of behavior
• Learned an array of responses acquired by an
  organism through experience.
• example Touching a hot stove as a child and
  hurting ones finger. That child has learned not
  to repeat that behavior.
• Inherited (innate) an array of responses that
  are part of genetic make-up of the organism
  "present at birth. The behavior is performed in
  virtually the same way by all members of a
  species.
• example If a mother goose happens to bump her
  egg out of the nest, she always retrieves it in
  the same manner. (Campbell et al., p 705).

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III. Introduction to Animal Behavior (cont.)

• Common terms used to describe innate locomotor
  responses of invertebrate animals

1. Taxis oriented or directed movement toward
or away from stimulus
2. Kinesis random movement toward or away from
stimulus but not necessarily oriented by it.
3. Positive response movement toward stimulus
4. Negative response movement away from stimulus
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III. Introduction to Animal Behavior (cont.)

• Some common stimuli resulting in movement include

• photo reaction to light - note that darkness
  is not the stimulus darkness is simply the
  absence of light.

• thermo reaction to temperature

• hygro (hydro) reaction to moisture or humidity

• thigmo reaction to contact (touch)

• chemo reaction to chemical stimulus

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III. Introduction to Animal Behavior (cont.)

• Ethology is the study of what animals do, and
  how and why they do it.
• Anthropomorphism attribution of human
  characteristics to nonhuman beings and things.
• example Saying that a bird sings on a
  beautiful morning because it is happy is an
  anthropomorphic statement. An ethological
  explanation of the same event might be that the
  bird is singing to communicate things to other
  members of the population, for example its
  availability for mating, or territorial
  occupation.

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IV. Scientific Method

• Record Observations about some behavior.
• Formulate Hypotheses based on known facts which
  account for the observed phenomena.
• Test each hypothesis by performing controlled
  experiments.
• For each experiment there will be a control
  group and an experimental group. All treatments
  will be exactly the same for both groups except
  that the control group will not be tested for the
  factor being studied.
• 4. Using statistics you reject or fail to reject
  the hypothesis.
• Note One can never definitely prove that a
  hypothesis is true because one can never be
  certain that we have examined all of the relevant
  evidence. Therefore we say fail to reject
  instead of accept or prove.

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IV. Scientific Method (cont.)

• NOTE For this set of experiments you are not
  going to use statistical tests to support/refute
  your four hypotheses.
• Therefore, an arbitrary cut-off point of 60 of
  the sow bugs responding to a variable will be
  considered as a significant response for use in
  rejecting or failing to reject your original
  hypotheses.
• NOTE Use the terms Reject or Fail to Reject
  when referring to the results of testing a
  hypothesis. Do not say accept.

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IV. Scientific Method (cont.)

• Example using the scientific method
• You observe that nightcrawlers are commonly found
  underground during the day, and above ground at
  night.
• Based on these observations you hypothesize that
  nightcrawlers move away from light thus
  exhibiting a photonegative response. You predict
  from this hypothesis that several randomly
  selected nightcrawlers placed in a light gradient
  would move toward the dark.
• You design and conduct an experiment using
  nightcrawlers and a box with a light on one end,
  and a dark cover over the other end.
• Based on the results of the experiment, you
  reject or fail to reject the hypothesis.

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V. Classification of (Woodlice)

• Kingdom- Animalia
• Phylum- Arthropoda This is the largest Phylum
  in the animal kingdom. They are invertebrates
  with a hard exoskeleton, and jointed appendages.
  examples include spiders, insects, crustaceans,
  centipedes, millipedes, horseshoe crabs, etc.
• Class- Crustacea examples include crabs,
  shrimp, lobsters, crayfish, and woodlice.
• Order- Isopoda This is one of the largest
  orders of crustaceans. Most species are marine,
  but few are terrestrial.The body is
  characteristically dorsoventrally flattened. The
  first segment of the thorax is fused with the
  head.
• Suborder- Oniscoidea These include the
  amphibious and terrestrial isopods.
• Family- Porcellionidae These are the sow
  bugs. Most species are unable to curl into a
  tight ball.
• Genus- Porcellio
• Species- Porcellio scaber

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V. Biology of Woodlice
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V. Biology of Woodlice (cont.)
Dorsal View
Ventral View
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V. Biology of Woodlice (cont.)

• Pleopods (referred to as "gills") modified
  abdominal segments with thin walls and air
  channels which connect to outside through a small
  pore. These structures enable Gas Exchange in the
  terrestrial woodlice, Porcellio scaber.

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V. Biology of Woodlice (cont.)

• Female broodpouch

young
brood pouch
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Laboratory Procedures Preserved Sow Bug drawings

• Make 2 labeled sketches of the preserved sow bug,
  one showing ventral (bottom/belly) side and one
  showing the dorsal (top/back) side.
• Identify the structures listed on p 6.
• Label measurements of length and width (cm)
• NOTE Do not copy the drawing from the overhead
  or from your text (zero credit for unoriginal
  drawings). These will be included in your lab
  reports in the results section.

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Laboratory Procedures Formulate three Hypotheses

• Using the information provided to you on page 5
  (section IV) formulate three hypotheses about the
  response of sow bugs to
• Light intensity (high/low)
• Moisture gradient (moist/dry)
• Temperature gradient (warm/cool)
• Write down your first three hypotheses on a 3x5
  card .

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Laboratory Procedures Conduct the First Three
Experiments

• Conduct the three experiments (in random order).
• Make and record observations for each experiment.
  
• Answer the following question for each
  experiment Do the sow bugs show a kinesis or a
  taxis and is the response positive or negative?

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Laboratory Procedures Formulate your 4th
Hypothesis

• With your partner, choose two variables to test
  simultaneously, ex. Light and moisture.
• Formulate a 4th hypothesis about the response of
  sow bugs to two interacting variables, and
  predict which variable provokes the stronger
  locomotor response.
• Write down your 4th hypothesis on a 3x5 card.

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Laboratory Procedures Design and Run the
Experiment

• With your partner you need to determine how you
  are going to test the two variables together.
• Once you have a plan, ask me to verify that your
  experiment will test your hypothesis.
• Conduct your experiments.
• Make and record observations for each experiment.

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Laboratory Procedures Experimental Design for
Locomotor Response to Two Variables

• You are testing how the locomotor response of sow
  bugs varies with respect to interactions between
  two environmental variables.
• example How is the sow bugs response to light
  intensity influenced by temperature?

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Laboratory Procedures Experimental Design for
Locomotor Response to Two Variables

• This is an Ideal setup, because in two steps it
  provides the sow bugs with four possible
  combinations. The second step will enable you to
  determine which variable produces the greater
  response.

Step One Step Two
WET DRY
WET DRY
DARK
DARK