Ethology

Ethology is the scientific study of animal behavior considered as a branch of zoology. A scientist who practices ethology is called an ethologist.

The desire to understand the animal world has made ethology a rapidly growing field, and even since the turn of the 21st century, many prior understandings related to diverse fields such as animal communication, personal symbolic name use, animal emotions, animal culture and learning, and even sexual conduct, long thought to be well understood, have been revolutionized, as have new fields such as neuroethology.

Etymology

The term "ethology" is derived from the Greek word "ethos" (ήθος), meaning "custom". Other words derived from the Greek word "ethos" include "ethics" and "ethical." The term was first popularized in English by the American myrmecologist William Morton Wheeler in 1902. An earlier, slightly different sense of the term was proposed by John Stuart Mill in his 1843 System of Logic. He recommended the development of a new science, "ethology," whose purpose would be the explanation of individual and national differences in character, on the basis of associationistic psychology. This use of the word for this purpose was never adopted.

Differences and similarities with comparative psychology

Comparative psychology also studies animal behavior, but, as opposed to ethology, construes its study as a branch of psychology rather than as one of biology. Thus, where comparative psychology sees the study of animal behavior in the context of what is known about human psychology, ethology sees the study of animal behavior in the context of what is known about animal anatomy and physiology. Furthermore, early comparative psychologists concentrated on the study of learning and tended to look at behavior in artificial situations, whereas early ethologists concentrated on behavior in natural situations, tending to describe it as instinctive. The two approaches are complementary rather than competitive, but they do lead to different perspectives and sometimes to conflicts of opinion about matters of substance. In addition, for most of the twentieth century, comparative psychology developed most strongly in North America, while ethology was stronger in Europe, and this led to different emphases as well as somewhat differing philosophical underpinnings in the two disciplines. A practical difference is that early comparative psychologists concentrated on gaining extensive knowledge of the behavior of very few species, while ethologists were more interested in gaining knowledge of behavior in a wide range of species in order to be able to make principled comparisons across taxonomic groups. Ethologists have made much more use of a truly comparative method than comparative psychologists ever have. Despite the historical divergence, most ethologists (as opposed to behavioural ecologists), at least in North America, teach in psychology departments.

Darwinism and the beginnings of ethology

Because ethology is understood as a branch of biology, ethologists have been particularly concerned with the evolution of behavior and the understanding of behavior in terms of the theory of natural selection. In one sense, the first modern ethologist was Charles Darwin, whose book, The expression of the emotions in animals and men, influenced many ethologists. He pursued his interest in behavior by encouraging his protégé George Romanes, who investigated animal learning and intelligence using an anthropomorphic method that did not gain scientific support.

Other early ethologists, such as Oskar Heinroth and Julian Huxley, instead concentrated on behaviors that can be called instinctive, or natural, in that they occur in all members of a species under specified circumstances. Their first step in studying the behavior of a new species was to construct an ethogram (a description of the main types of natural behavior with their frequencies of occurrence). This approach provided an objective, cumulative base of data about behavior, which subsequent researchers could check and build on.

The fixed action pattern and animal communication

An important step, associated with the name of Konrad Lorenz though probably due more to his teacher, Oskar Heinroth, was the identification of fixed action patterns (FAPs). Lorenz popularized FAPs as instinctive responses that would occur reliably in the presence of identifiable stimuli (called sign stimuli or releasing stimuli). These FAPs could then be compared across species, and the similarities and differences between behavior could be easily compared with the similarities and differences in morphology. An important and much quoted study of the Anatidae (ducks and geese) by Heinroth used this technique. The ethologists noted that the stimuli that released FAPs were commonly features of the appearance or behavior of other members of their own species, and they were able to show how important forms of animal communication could be mediated by a few simple FAPs. The most sophisticated investigation of this kind was the study by Karl von Frisch of the so-called "dance language" underlying bee communication. Lorenz developed an interesting theory of the evolution of animal communication based on his observations of the nature of fixed action patterns and the circumstances in which animals emit them.

Imprinting

A second important finding of Lorenz concerned the early learning of young nidifugous birds, a process he called imprinting. Lorenz observed that the young of birds such as geese and chickens spontaneously followed their mothers from almost the first day after they were hatched, and he discovered that this response could be imitated by an arbitrary stimulus if the eggs were incubated artificially and the stimulus was presented during a critical period (a less temporally constrained period is called a sensitive period) that continued for a few days after hatching.

Tinbergen's four questions for ethologists

Lorenz's collaborator, Niko Tinbergen, argued that ethology always needed to pay attention to four kinds of explanation in any instance of behavior:

Function: how does the behavior impact on the animal's chances of survival and reproduction?
Causation: what are the stimuli that elicit the response, and how has it been modified by recent learning?
Development: how does the behavior change with age, and what early experiences are necessary for the behavior to be shown?
Evolutionary history: how does the behavior compare with similar behavior in related species, and how might it have arisen through the process of phylogeny?

The flowering of ethology

Through the work of Lorenz and Tinbergen, ethology developed strongly in continental Europe in the years before World War II. After the war, Tinbergen moved to the University of Oxford, and ethology became stronger in the UK, with the additional influence of William Thorpe, Robert Hinde, and Patrick Bateson at the Sub-department of Animal Behaviour of the University of Cambridge, located in the village of Madingley. In this period, too, ethology began to develop strongly in North America.

Lorenz, Tinbergen, and von Frisch were jointly awarded the Nobel Prize in 1973 for their work in developing ethology.

Social ethology and recent developments

In 1970, the English ethologist John H. Crook published an important paper in which he distinguished comparative ethology from social ethology, and argued that much of the ethology that had existed so far was really comparative ethology, looking at animals as individuals, whereas in the future, ethologists would need to concentrate on the behaviour of social groups of animals and the social structure within them.

Indeed, E. O. Wilson's book Sociobiology appeared in 1975, and since that time the study of behavior has been much more concerned with social aspects. It has also been driven by the stronger, but more sophisticated, Darwinism associated with Wilson and Richard Dawkins. The related development of behavioral ecology has also helped transform ethology. Furthermore, a substantial rapprochement with comparative psychology has occurred, so the modern scientific study of behavior offers a more or less seamless spectrum of approaches – from animal cognition to more traditional comparative psychology, ethology, sociobiology and behavioral ecology.

Notes

There are often mismatches between human senses and those of the organisms they are observing. To compensate, ethologists often reach all the way back to epistemology to give them the tools to predict and avoid misinterpretation of data.

List of ethologists

People who have made notable contributions to the field of ethology (many are comparative psychologists):