Describing Action Patterns
In order to study and measure behavior you must break the behavior up into units, called action patterns. These become evident to you when you watch an animal. As you become familiar with its behavior, you immediately see that its behavior is not continuous. Instead, the animal performs discrete, repeatable acts that you can identify. These discrete, repeated acts or bodily postures are what we call action patterns.
Action Patterns, then are:
• discrete, complex muscular movements involving many muscular contractions that are closely associated temporally
• repeated in essentially the same manner time after time (i.e. they are stereotyped) and
• they are similar among individuals of the same species (i.e. they are species-typical).
Action patterns are often defined in terms of the following characteristics:
• the form of the action.
• the velocity of the action -- how rapid are the movements of the action pattern?
• the duration or how long the movements are held in different positions.
• the amplitude or the height of the action.
• the orientation of the behavior towards objects in the environment, including conspecifics.
Look at the action patterns for mallard ducks depicted below. One is a posture (head-round) while the others all involve motions from simple head shaking to more complex motions that involve much of the body
Major Approaches to Quantifying Behavior: Survey vs. Focal
Once you have completed your catalog of behaviors, you are ready to quantify how your animal spends its time. There are two main methods to do this:
Survey approach: Watch many individuals at the same time. At systematic (or randomized) times, you count the number of individuals performing each possible behavior that you previously cataloged. For example, if you are watching a flock of ten geese in a lake, you might set your timer to alert you at one minute intervals. When the timer goes off, you note what each of the geese in the flock are doing at that instant, as well as the context and consequences of their actions. You will repeat this every minute for your entire observation period. Taking survey data in the field also is facilitated by creating a data form that can be filled in quickly. We are less likely to use the survey method in this course, but it can be used if necessary.
Focal approach: Locate a single individual and follow its behavior for a standard time (or as long as possible up to that time). If a focal individual moves out of your view, then you start a new sequence of observations on a new focal individual. Selecting the focal animal can be systematic (e.g. only watch males) or randomized (select a random number from a table, then follow the nth individual encountered). During a focal study, you should record the following data as they occur:
- the context (date, time, location, weather, habitat, social context)
- the focal animal ID (if you can identify them uniquely, or just by #1, #2, etc)
- the sequence of behaviors
- the duration of behaviors (using a stopwatch)
- the immediate consequences (e.g. responses of other individuals, etc.)
You won't have time to take extensive notes during focal observations. Your catalog of behaviors (action patterns) must be used to make organized data sheets that allow you to record data quickly and efficiently during the observation period, and to tabulate the results accurately afterward. A well-written catalog of behaviors will allow the creation of a form for collecting data for the quantification phase of the ethogram.