Behavior (biology)

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When the behavior of a living being is referred to in the Behavioral Biology "the totality of his movements, vocalizations and postures." This also includes all externally recognizable changes “which serve to facilitate mutual understanding and can thus trigger behaviors in the respective partner ”, for example color changes and the secretion of pheromones : “A behavior is mostly expressed in muscle movements, but occasionally also in glandular activity or Pigment migration ". On the one hand, behavior is the entirety of such life processes, but on the other hand, individual behaviors that occur during a certain period of time can also be called behavior .

With the death of an individual, all his life processes end and therefore his behavior ends too.

Behavior and behavioral research

According to Gerard Baerends (1956), as in the study of other biological objects, three questions can be asked when examining elements of behavior: “1. What form do the behavioral elements have and what mechanisms do they come about? - 2. What is their function? - 3. How did they develop in the course of evolution? ”In 1987 Irenäus Eibl-Eibesfeldt added that behavior is understood by evolutionary biologists as an organism's ability to adapt to its environment, influenced by genes and learning :“ Behavioral researchers try to find out what causes behavior physiologically, in which way it contributes to suitability [what is meant: to survival] and how it developed in the course of tribal and individual history . The answers to the different questions require different methods to those in the classical physiology , ecology , the motivation - and System Research , the developmental physiology , the genetics and comparative morphology tie ".

To research the behavior of individuals of a species, behavioral biologists often first create an ethogram and then register each behavior in a behavior log.

Causes of behavior

Model: regulation of behavior. The control loops can contain both self- booster effects and
negative feedback .

A certain behavior can be triggered by simple internal, physiological stimuli (for example: feeling hungry ) as well as by more complex, but also innate components (" instinctive behavior "; one example is the search for food). Behavior can also be triggered in response to changes in the environment; in this case it is triggered by exogenous stimuli. A clear statement as to the extent to which internal and external causes are responsible for a certain behavior is often not possible for the observer. What is certain today is that innate behavior can also be changed through experience - through learning .

Almost every study in the field of behavioral biology that is emerging today is devoted to the search for the causes of behavior; Purely descriptive studies, such as the classic comparative behavioral research and behaviorism , are very rare . Nevertheless, even today, a clear description of behavior is always the prerequisite for a more detailed analysis.

In general, two types of causes can be distinguished from one another: the proximate and the ultimate causes of behavior:

  • Proximate causes are the immediate causes: Which internal (physiological, neurological, hormonal) and external (environmental) factors produce an observable behavior?
  • Ultimate causes are the characteristics that emerged in the course of the tribal history : On the basis of which genes and which inherited behavioral programs does the observable behavior take place?

Often a third cause must also be considered:

  • the influences of previously shown behavior: which individual experiences ( learning , shaping ) influence the course of the observable behavior.

Accordingly, many research areas contribute to research into the phenomenon of behavior . In addition to the various directions in behavioral biology, these are above all:


“Behavior is primarily built up from muscle actions ( contraction , relaxation ); In addition, other activities such as secretion and changes in chromatophores can also be included in behavior. If a movement of a more or less comprehensive body part is to result from these actions, then they have to be ordered in space and time. ”Behavior is therefore always linked to living individuals or groups - stones can also break off a cliff and move downwards; however, this movement was entirely caused by external influences. It is not an "own contribution" of an actively acting or reacting subject for whom the change, movement, posture or expression referred to as behavior has a specific function (a purpose, a meaning). For a tick that drops from a bush onto a warm-blooded animal, however, the fall undoubtedly has a function. The term behavior is therefore usually only applied to living beings with the ability to process information, e.g. B. a nervous system applied, which are capable of active locomotion (at least temporarily). However, the movements of firmly attached cnidarians can also be classified as behavior.

Calm and rigidity

Behavior is not only linked to visible movements or changes in an organism. Behavior also manifests itself in symptoms such as resting, sleeping , wearing rigid , fear Rigid or Lauerstellung that over a certain period of time stationary states. A female butterfly sitting still, emitting fragrances, or a person staring motionlessly into space (a “thinker”) behave even without recognizable movement.

One can try in a thought experiment to find situations in which one does not behave - even extremely passive states such as deep sleep can hardly be attributed to this category of "non-behavior". Behavioral biologists have therefore modified a sentence formulated by Paul Watzlawick in his book Menschliche Kommunikation as follows: "You cannot non-behave." Extreme situations that completely question the independence and independence of the individual (for example the process of dying and deep unconsciousness) , can be understood as an exception to Watzlawick's formulation.


Occasionally, the word behavior is also used by biologists in a very broad sense: namely that every body cell and every organ in an organism “behaves” or should behave in a defined way. For example, the stinging cells of medusa can still fulfill their function for a relatively long time after an animal has washed up on the beach and no further signs of life can be observed on it. In general, however, this type of behavior within a living being is assigned to the field of physiology (see also: Pathophysiology ). The interrelationships between physiology and behavior in the ethological sense are extensive and are the subject of research in many disciplines in behavioral biology.

Involuntary movements

One limitation of the definition of behavior ultimately refers to visible and significant for the individual movements, as can be interpreted passively however pure: The movements of the intestine or the mere secretion of sweat from the skin glands in heat one will not generally considered behavior designate . On the other hand, activities such as weaning off feces and urine clearly fall into this category.

Comparison across species boundaries

Researchers from the environment of the first ethology and later ethology direction of said behavioral biology were the first systematically the behavior of different species have compared. Konrad Lorenz, for example, was valued in specialist circles primarily for his comparative studies on ducks and geese, which were published in the 1930s: He had related behaviors to one another in a similar way as had long been the case in comparative anatomy . In some cases, the tribal history of behavior could also be traced.

When comparing the behavior of different species, a distinction is made between homologous behavior and analogous behavior . Homologous behaviors are those that can be phylogenetically derived from one another, i.e. have the same origin. Analogous behaviors are those that have a comparable expression despite different origins. They are the result of phylogenetic adaptations to the same selection factors, for example the same habitats. Analogous behaviors can be observed in humans and domestic dogs.

While the comparison of the behavior of closely related species is widely accepted as a method of biological research today, most behavioral biologists - in contrast to laypeople - reject analogy conclusions from one species to a distantly related species. This applies in particular to the transfer of human behavior to animals. There are also hardly any experimental studies that allow, for example, moods such as sadness, anger, depression, etc. Ä., Which are peculiar to humans, also to assign animals. Nevertheless, Harry Harlow's experiments, for example, have shown that at least many primates can be put into moods that are extremely similar to those of humans.

Even with domesticated animals, especially those that live in natural surroundings in social groups, changes in behavior can be determined when the caregiver is lost, which are comparable to those of a grieving person. This also applies to some animal species in which the adult individuals live in long-term sexual relationships. Konrad Lorenz made the intensive search behavior of female gray geese who have lost their partner known.

Examples of complex behaviors


Also, plants , fungi , protists and bacteria react to stimuli of the environment, and these reactions can take as in animals similar forms:

Nevertheless, behavioral researchers (and also botanists ) traditionally do not speak of behavior here, but generally of reaction . This then includes all biochemical and biophysical processes. With these forms of reaction are u. a. the physiology and the ecology.

See also

Web links

Wikibooks: Animal Behavior  - A guide to the hows and whys of animals interacting with each other and with the world around them

Individual evidence

  1. behavior . In: Klaus Immelmann : Grzimeks Tierleben , special volume behavior research. Kindler Verlag, Zurich 1974, p. 639.
  2. ^ Irenäus Eibl-Eibesfeldt : Outline of Comparative Behavioral Research. 7th edition. Piper, Munich and Zurich 1987, p. 17, ISBN 3-492-03074-2 .
  3. Gerard Baerends : Structure of animal behavior. In: Johann-Gerhard Helmcke (Hrsg.): Handbuch der Zoologie. Volume 8: Mammalia. 10th part, 1st half, 1956, p. 1.
  4. ^ Irenäus Eibl-Eibesfeldt: Outline of Comparative Behavioral Research, pp. 17-18.
  5. John Alcock : The behavior of animals from an evolutionary perspective. G. Fischer, Stuttgart, Jena and New York 1996, p. 24, ISBN 978-3-437-20531-6 .
  6. Gerard Baerends, Structure of Animal Behavior , p. 2.
  7. Konrad Lorenz : The friend in the environment of the bird. The conspecific as the triggering moment of social behavior. In: Journal of Ornithology. Volume 83 (Issue 2 and 3), 1935, pp. 137-215, 289-413, doi: 10.1007 / BF01905355 . Reprinted 1965 in: About animal and human behavior . Volume I.
  8. Karl-Heinz Skrzipek: Practical ethology. Teubner, Stuttgart 1978, ISBN 978-3-519-03603-6 , p. 37.