What follows in the next six sections is a step by step outline of an investigation of animal behavior using the inquiry method. The authors have used grooming behavior of the fruit fly Drosophila, but this exercise should be adaptable to many different species and behaviors. The important issue here is not the specific animal or behavior studied, but rather its use as an example of an inquiry-based experience. Such an experience will give students more input into the direction of the work, capitalizes on their prior knowledge, forces them to make decisions about experimental design and analysis, and challenges them to interpret data without depending on preconceived notions of what the “right” answer should be. Each of the following sections will outline the general procedures used in this type of exercise. The specific example using Drosophila and grooming behavior will be presented in parallel links to other pages.
1. Present the student with this simple question. Help students bring their own experiences to this problem. Students will know much more about animal behavior than they first realize. Depending on their level and background, comments from students will include:
Define different kinds of behavior (feeding behavior, locomotion, sexual
behavior, etc.)
Different methods of studying behavior (field studies vs. lab studies,
experimental manipulations vs. direct observations)
Using different animals (here you may suggest the behavior of plants
can also be studied)
2. Discuss the considerations involved in selecting a behavior and an
animal model for study.
This discussion can include issues of the particular questions being
asked, cost, care and housing of animals, ease of handling, techniques
and equipment needed for the study. Stress at this point that simple
questions and simple experiments can be just as valuable as costly and
complex experiments.
3. Discuss the first steps in a study of animal behavior (or any other study).
Here help the students realize they already know a great deal about the behavior of many animals (pets, movies, zoos, friends, and parents). What do they need to do to learn more about the basic behaviors of an animal? Stress the critical importance of careful observations. Use examples of scientists who have become “famous” by using their powers of observation (e.g. Jane Goodall, Charles Darwin, Wright brothers, Copernicus).
4. Select the animal for your exercise.
Using the previous discussion have the class, group, or teacher select
the animal which will best suit the interests, facilities, and time available.
The authors used the fruit fly Drosophila because of its ease in
handling, availability, large amount of background knowledge, etc.
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An ethogram is a catalog of an animal's (or species’) behavior (Lehner, 1996). It includes descriptions of the types of behavior an animal displays (feeding, locomotion, fighting, sexual, parenting). Ethograms can also be more refined and catalog the detailed motor patterns involved in these general categories of behavior. This exercise will focus on the grooming behavior of Drosophila, but other behaviors may also be suitable for class study (spider web construction, territorial behavior of fish, feeding behavior of students in the cafeteria).
Discuss with students the concept of an ethogram. An analogy to a glossary may be appropriate here. An ethogram is a glossary of the animals behavior providing the names and descriptions of the animal's behavior. Elicit from students the obvious need for common terms and descriptions in an ethogram (as in the binomial system of classification). The basic ideas of building an ethogram are simple and straightforward. First students will need to decide how to observe the animal (single animal or groups, free ranging or confined, directly or using video or other technology). Secondly, the students will need to decide how to record their observations (tape recording, video recording, etc.). These considerations sound simple, but students will soon realize many complications and questions will need to be resolved before they can get consistent and reliable data.
1. Once the setup issues have been resolved ask individual students to spend time observing the animal. Have them record the “different kinds” of behavior they see the animal perform. Let them define their own categories, but insist they write a description that is specific enough to be recognized by other students.
2. Have students compare their first ethograms and come to a common consensus for the number of different behaviors, their names, and descriptions. There will be students who classify general categories of behavior (feeding, walking, and grooming) and those that describe more detailed behaviors that belong to the more general categories (grooming the front legs, grooming the wings). This can lead to a discussion of which questions may be appropriate for general descriptions and others for more specific descriptions.
3. If a particular behavior such as grooming is to be studied in detail, an ethogram of that behavior must be produced. Use the same method described above. This time have the students restrict their observations and descriptions to behavior belonging to the selected category of behavior.
4. In this exercise the grooming behavior of flies will be studied.
However, the teacher should feel free to choose other behaviors to study
or let students suggest directions. Grooming behavior is used here
because it is obvious, has a number of easily recognized components, and
can be manipulated with several variables.
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The construction of an ethogram works well to hone the students’ appreciation of the need for accurate and consistent observations. The teacher may limit this exercise to the ethogram. However, it is important to point out to students that little or no quantitative information can be found in the ethogram an ethogram. Animal behavior is no exception to the need to characterize data with quantitative techniques (Lehner, 1996 and Douglas, 1979).
1. Ask students what other kinds of observations they could make in addition to the ethogram. Suggestions will probably include:
How often the animal engages in each behavior (frequency)?
How long the animal engages in each behavior (duration)?
How do the different behaviors appear in sequence relative to one another
(temporal distribution)?
2. Discuss with students how they could obtain these different types of data. Most school situations will make measuring duration difficult if the behaviors are performed in quick sequences. However frequency and temporal distribution are more accessible to students. A commonly used technique in animal behavior studies to analyze sequences of behavior is called Markov chain analysis, which uses the common Chi-Square statistical test. What is required is a recording of the sequences of behavior displayed by the animal in the order they occurred. This is best done by having students use a tape recorder to record the data as they observe the animal. Video recording has the advantage of permitting students to review the same sequence of behavior over again. The teacher and students will find that they will have to be creative and work well together to record this type of data.
3. In brief, a Markov chain analysis consists of counting how many times each of the behaviors in the ethogram is followed by each of the other remaining behaviors in the ethogram. This produces a table of “transition frequencies”. The Chi-Square test can be applied to the transition frequency table to determine which pairs of transitions are more or less commonly observed than would be expected if the behaviors occurred at random. In other words, the Chi-Square test will confirm which behaviors show a higher (or lower) probability of forming paired sequences. This will reveal patterns of sequences that characterize the behavior (Lehner 1996 and Dawkins, 1976).
4. Once the Markov analysis is done, have the students spend time discussing
the “structure of the behavior”. This is one level of analysis above
the ethogram. Students will quickly realize that the behavior of
their animal is not a random collection of events, but shows patterns of
very predictable sequences of behaviors. For example in grooming behavior
of flies, they most often begin by grooming the head and mouth parts for
a period of time before grooming the wings or abdomen rather than randomly
grooming different parts of the body.
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The ethogram provides the “dictionary” or “vocabulary” of the behavior. The Markov analysis provides a degree of quantitative description by relating the behaviors to one another. These approaches may suggest hypotheses for explaining the controlling mechanisms of the behavior. However, animal behavior is no different from any other area of science and can be studied by manipulating experimental variables and comparing results to controls (Tinbergen, N. 1956). If the teacher expects to carry this exercise to this level of analysis, some background will probably be necessary for the students. If students have not studied the scientific method, this is an ideal place for its introduction.
Examples of this level of analysis can be found in any textbook of animal
behavior. They include studying behavior by changing levels of hormones
that influence reproductive behavior, manipulating stimuli used for orientation,
and altering genes that control mating behavior. Having students
suggest ways to do this with their animal may be difficult. They
will generally have limited knowledge to use at this point. Experimental
manipulations with species used may present difficult technical, financial,
or ethical problems. Using an insect such as Drosophila eliminates
many of these difficulties.
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