BIOLOGY Volume 2 - A Guide to General Biology - 2004

17. ANIMAL COORDINATION AND REGULATION

17.7. The Study of Behaviour (Ethology)

Behaviour can be defined as an Organism's outwardly directed actions in response to stimuli arising from a particular situation. These actions modify the organism's relationship with its environment in a specific way and have an adaptive value, meaning they contribute to the preservation of the species. All living creatures possess a varying range of behavioural activity, which depends on their ability to react to specific stimuli. These reactions can range widely—from relatively simple ones, such as a plant growing towards a light source, to complex forms of behaviour such as territorial defence, courtship, mating, and parental care in birds and mammals.

Plant behaviour is limited to movements driven by growth or changes in turgor pressure; it is stereotyped and predictable. This refers primarily to Tropisms, which are described in detail in Section 16.1¹.

Animal behaviour is vastly more complex and diverse, making its study—and particularly drawing scientifically sound Conclusions from observations—immensely more difficult. There are three main approaches to studying animal behaviour: vitalist, mechanistic, and ethological.

The Vitalist Approach

Proponents of this approach, also known as the naturalistic approach, seek to explain animal behaviour solely on The basis of directly observable actions and attempt to link these actions to environmental changes. They completely reject the possibility of studying animals outside their natural habitat. Rooted in the traditions of "natural history," this approach has yielded a wealth of valuable data; however, these data cannot be considered strictly scientific, as they are merely descriptions of past events that cannot be tested experimentally.

The Mechanistic Approach

This approach, also known as the zoopsychological approach, is strictly experimental; it involves studying specific forms of behaviour under controlled laboratory conditions. It has been criticized for the artificiality of the experimental conditions imposed on the animal, The Nature of the behavioural responses, and the interpretation of the results. Nevertheless, this method, pioneered largely by I. P. Pavlov, is widely used in comparative psychology.

The Ethological Approach

This is the most modern approach to The Study of animal behaviour, combining the two Methods described above. Proponents of this school attempt to explain behavioural reactions observed in natural conditions by linking them to specific stimuli and subsequently verifying their conclusions through experiments. The ethological approach was developed by Lorenz, von Frisch, and Tinbergen.

When studying animal behaviour, one must exercise extreme caution in interpreting observational results to avoid subjectivity. For example, researchers must guard against putting themselves in the animal's place (anthropocentrism), interpreting facts through the lens of human experience (anthropomorphism), or explaining the cause of an observed phenomenon based on its predetermined outcome (teleology).

Recent advances in the study of animal behaviour have been greatly facilitated by breakthroughs in video and sound recording technology. Infrared photography has made it possible to film animals at night. Time-lapse photography allows researchers to record slow processes (such as insect moulting), while high-speed photography captures very rapid ones (such as wingbeats in flight) so they can be viewed at a speed more suitable for analysis. Miniature tape recorders, directional remote microphones, acoustic spectrographs, and computers have significantly simplified the study of animal acoustic communication. Animal Migrations are now studied using miniaturized Transmitters implanted or attached to the body, which emit signals detectable by electronic telemetry systems such as radar and satellites. This is particularly useful for tracking the migrations of mammals, birds, and locusts.

However, regardless of the approach or method used to study behaviour, the explanation of behavioural reactions must always encompass the entire chain of events from stimulus to response, covering all levels of internal Organization that link cause and effect.

In the broadest terms, behaviour can be divided into two types—innate and acquired (the result of learning). However, there is no sharp boundary between them, and most behavioural reactions in higher organisms undoubtedly contain elements of both. Nevertheless, for the sake of simplicity in our Overview, these Two Types of behaviour will be considered separately.

¹ Plants also exhibit so-called Nastic Movements (nasties), which are reactions to environmental conditions but, unlike tropisms, are not directed toward the stimulus. An example is the opening and closing of flowers depending on the time of day. Sometimes plant Taxes are mentioned with reference to motile unicellular Algae, but in modern Classification systems such organisms belong to a different kingdom of life. — Trans. note.