About Ethograms
Overview and Meaning
The study of animal behavior begins with a library of behaviors, called an ethogram. An ethogram is a list of species-specific behaviors describing the elements and function of each behavior. Normally, the best ethograms are functional; they are organized into categories that reflect meaningful distinctions to the animal.
The word ethogram is often used confusingly to mean two different things: the species ethogram, and the experimental ethogram. The species ethogram is a master list of all known behaviors for the species. Whereas the experimental ethogram is a distillation and reorganization of this list into the behaviors that are relevant to the hypothesis being tested. Thus very unlike many of the automated behavioral neuroscience paradigms, where a huge number of individual variables are produced, a well designed ethological study will narrow down the behaviors observed to exactly the right ones to test the specific hypotheses at hand.
Experimental ethograms are usually constructed to be exclusive and exhaustive. These terms refer to the operationalization (i.e. the rules the observer uses to make decisions) of the categories in the ethogram.
An exclusive ethogram is one where each behavior performed by the animal can only be categorized as one behavior in the ethogram - that is, the animal can only be recorded as doing one thing at a time. So rather like differential diagnoses in medicine, an exclusive ethogram will often define a behavior by exclusion (for example the postures involved in still and alert and sleep are very similar, so the definitions for each involve exclusionary statements so that the observer can distinguish them).
An exhaustive ethogram is one where every behavior performed by the animal has a category in the ethogram, this is normally achieved in an experimental ethogram by lumping all the behaviors of no interest to the hypothesis being tested in an 'other' category. This greatly speeds the recording of behavior, as behaviors irrelevant to the hypothesis can simply be ignored.
Experimental SOPs comprise the ethogram, and the observational methods used. Again, choosing the right method is a skilled endeavor, because different observational methods have different strengths and weakness, and are typically used to answer different kinds of hypotheses. To make these decisions easier, some commonly used experimental SOPs for particular research questions are provided on the methods and protocols page.
Constructing the mouse species ethogram
We conducted an extensive literature review to identify existing mouse ethograms (please see the ethogram comparison page) and synthesized the results into a complete ethogram. We isolated behavioral examples from archived mouse videos illustrating particular behaviors and established standard operating procedures.
When constructing an ethogram there are many possible categorizations for behavior, however there are four common schemes to keep in mind:
1. Function
2. Time of day
3. Mechanism (consummatory or appetitive)
4. Ontogeny (point in life)
In the species mouse ethogram we have categorized behaviors by function. In addition, we have outlined a page on grouping behaviors by other categorization schemes. We have also included a page on miscellaneous behaviors for behaviors that do not fit well into this classification, have been described under multiple contexts, or were unclear in their meaning from the original authors.