![Lizard draft](https://upload.wikimedia.org/wikipedia/commons/0/07/Lizard_draft.svg)
Ethology is the
scientific
Science is a systematic endeavor that builds and organizes knowledge in the form of testable explanations and predictions about the universe.
Science may be as old as the human species, and some of the earliest archeological evidence for ...
study of
animal
Animals are multicellular, eukaryotic organisms in the Kingdom (biology), biological kingdom Animalia. With few exceptions, animals Heterotroph, consume organic material, Cellular respiration#Aerobic respiration, breathe oxygen, are Motilit ...
behaviour, usually with a focus on behaviour under natural conditions, and viewing behaviour as an
evolution
Evolution is change in the heritable characteristics of biological populations over successive generations. These characteristics are the expressions of genes, which are passed on from parent to offspring during reproduction. Variation ...
arily
adaptive trait.
Behaviourism
Behaviorism is a systematic approach to understanding the behavior of humans and animals. It assumes that behavior is either a reflex evoked by the pairing of certain antecedent stimuli in the environment, or a consequence of that individual ...
as a term also describes the scientific and objective study of animal behaviour, usually referring to measured responses to stimuli or to trained behavioural responses in a
laboratory
A laboratory (; ; colloquially lab) is a facility that provides controlled conditions in which scientific or technological research, experiments, and measurement may be performed. Laboratory services are provided in a variety of settings: physic ...
context, without a particular emphasis on evolutionary adaptivity. Throughout history, different
naturalists have studied aspects of animal behaviour. Ethology has its scientific roots in the work of
Charles Darwin
Charles Robert Darwin ( ; 12 February 1809 – 19 April 1882) was an English naturalist, geologist, and biologist, widely known for his contributions to evolutionary biology. His proposition that all species of life have descended fr ...
and of American and German ornithologists of the late 19th and early 20th century, including
Charles O. Whitman,
Oskar Heinroth, and
Wallace Craig
Wallace Craig (1876–1954) was an American experimental psychologist and behavior scientist. He provided a conceptual framework for the study of behavior organization and is regarded as one of the founders of ethology. Craig experimentally studi ...
. The modern discipline of ethology is generally considered to have begun during the 1930s with the work of Dutch biologist
Nikolaas Tinbergen
Nikolaas "Niko" Tinbergen (; ; 15 April 1907 – 21 December 1988) was a Dutch biologist and ornithologist who shared the 1973 Nobel Prize in Physiology or Medicine with Karl von Frisch and Konrad Lorenz for their discoveries concerning the o ...
and Austrian biologists
Konrad Lorenz
Konrad Zacharias Lorenz (; 7 November 1903 – 27 February 1989) was an Austrian zoologist, ethologist, and ornithologist. He shared the 1973 Nobel Prize in Physiology or Medicine with Nikolaas Tinbergen and Karl von Frisch. He is often regarded ...
and
Karl von Frisch
Karl Ritter von Frisch, (20 November 1886 – 12 June 1982) was a German-Austrian ethologist who received the Nobel Prize in Physiology or Medicine in 1973, along with Nikolaas Tinbergen and Konrad Lorenz.
His work centered on investigations o ...
, the three recipients of the 1973
Nobel Prize in Physiology or Medicine
The Nobel Prize in Physiology or Medicine is awarded yearly by the Nobel Assembly at the Karolinska Institute for outstanding discoveries in physiology or medicine. The Nobel Prize is not a single prize, but five separate prizes that, accord ...
. Ethology combines laboratory and field science, with a strong relation to some other disciplines such as
neuroanatomy
Neuroanatomy is the study of the structure and organization of the nervous system. In contrast to animals with radial symmetry, whose nervous system consists of a distributed network of cells, animals with bilateral symmetry have segregated, defi ...
,
ecology
Ecology () is the study of the relationships between living organisms, including humans, and their physical environment. Ecology considers organisms at the individual, population, community, ecosystem, and biosphere level. Ecology overlaps wi ...
, and
evolutionary biology
Evolutionary biology is the subfield of biology that studies the evolutionary processes (natural selection, common descent, speciation) that produced the diversity of life on Earth. It is also defined as the study of the history of life fo ...
. Ethologists typically show interest in a behavioural process rather than in a particular animal group, and often study one type of behaviour, such as
aggression, in a number of unrelated species.
Ethology is a rapidly growing field. Since the dawn of the 21st century researchers have re-examined and reached new conclusions in many aspects of
animal communication,
emotions
Emotions are mental states brought on by neurophysiological changes, variously associated with thoughts, feelings, behavioral responses, and a degree of pleasure or displeasure. There is currently no scientific consensus on a definition. ...
,
culture
Culture () is an umbrella term which encompasses the social behavior, institutions, and norms found in human societies, as well as the knowledge, beliefs, arts, laws, customs, capabilities, and habits of the individuals in these groups.Tyl ...
,
learning
Learning is the process of acquiring new understanding, knowledge, behaviors, skills, value (personal and cultural), values, attitudes, and preferences. The ability to learn is possessed by humans, animals, and some machine learning, machines ...
and
sexuality that the scientific community long thought it understood. New fields, such as
neuroethology
Neuroethology is the evolutionary and comparative approach to the study of animal behavior and its underlying mechanistic control by the nervous system. It is an interdisciplinary science that combines both neuroscience (study of the nervous syste ...
, have developed.
Understanding ethology or animal behaviour can be important in
animal training
Animal training is the act of teaching animals specific responses to specific conditions or stimuli. Training may be for purposes such as companionship, detection, protection, and entertainment. The type of training an animal receives will va ...
. Considering the natural behaviours of different species or breeds enables trainers to select the individuals best suited to perform the required task. It also enables trainers to encourage the performance of naturally occurring behaviours and the discontinuance of undesirable behaviours.
[
]
Etymology
The term ''ethology'' derives from the
Greek language
Greek ( el, label=Modern Greek, Ελληνικά, Elliniká, ; grc, Ἑλληνική, Hellēnikḗ) is an independent branch of the Indo-European family of languages, native to Greece, Cyprus, southern Italy (Calabria and Salento), southern Al ...
:
ἦθος
Ethos ( or ) is a Greek word meaning "character" that is used to describe the guiding beliefs or ideals that characterize a community, nation, or ideology; and the balance between caution, and passion. The Greeks also used this word to refer to ...
, ''
ethos
Ethos ( or ) is a Greek word meaning "character" that is used to describe the guiding beliefs or ideals that characterize a community, nation, or ideology; and the balance between caution, and passion. The Greeks also used this word to refer to ...
'' meaning "character" and , ''
-logia'' meaning "the study of". The term was first popularized by American
myrmecologist
Myrmecology (; from Greek: wikt:μύρμηξ, μύρμηξ, ''myrmex'', "ant" and λόγος, ''logos'', "study") is a branch of entomology focusing on the science, scientific study of ants. Some early myrmecologists considered ant society as th ...
(a person who studies ants)
William Morton Wheeler
William Morton Wheeler (March 19, 1865 – April 19, 1937) was an American entomologist, myrmecologist and Harvard professor.
Biography Early life and education
William Morton Wheeler was born on March 19, 1865, to parents Julius Morton Wheeler ...
in 1902.
History
The beginnings of ethology
![Charles Darwin 1880](https://upload.wikimedia.org/wikipedia/commons/4/45/Charles_Darwin_1880.jpg)
Because ethology is considered a topic of biology, ethologists have been concerned particularly with the
evolution
Evolution is change in the heritable characteristics of biological populations over successive generations. These characteristics are the expressions of genes, which are passed on from parent to offspring during reproduction. Variation ...
of behaviour and its understanding in terms of
natural selection
Natural selection is the differential survival and reproduction of individuals due to differences in phenotype. It is a key mechanism of evolution, the change in the heritable traits characteristic of a population over generations. Charle ...
. In one sense, the first modern ethologist was
Charles Darwin
Charles Robert Darwin ( ; 12 February 1809 – 19 April 1882) was an English naturalist, geologist, and biologist, widely known for his contributions to evolutionary biology. His proposition that all species of life have descended fr ...
, whose 1872 book ''
The Expression of the Emotions in Man and Animals
''The Expression of the Emotions in Man and Animals'' is Charles Darwin's third major work of evolutionary theory, following ''On the Origin of Species'' (1859) and '' The Descent of Man'' (1871). Initially intended as a chapter in ''The Desce ...
'' influenced many ethologists. He pursued his interest in behaviour by encouraging his protégé
George Romanes
George John Romanes FRS (20 May 1848 – 23 May 1894) was a Canadian-Scots evolutionary biologist and physiologist who laid the foundation of what he called comparative psychology, postulating a similarity of cognitive processes and mechanism ...
, who investigated animal learning and intelligence using an
anthropomorphic
Anthropomorphism is the attribution of human traits, emotions, or intentions to non-human entities. It is considered to be an innate tendency of human psychology.
Personification is the related attribution of human form and characteristics t ...
method,
anecdotal cognitivism
Anecdotal cognitivism is a method of research using anecdotal, and anthropomorphic evidence through the observation of animal behaviour. A psychological methodology that attributes mental states to animals on the basis of anecdotes and on the obs ...
, that did not gain scientific support.
Other early ethologists, such as
Eugène Marais
Eugène Nielen Marais (; 9 January 1871 – 29 March 1936) was a South African lawyer, naturalist, poet and writer. He has been hailed as an intellectual genius and an Afrikaner hero.
His early years, before and during the Boer War
Marais w ...
, Charles O. Whitman,
Oskar Heinroth, Wallace Craig and
Julian Huxley, instead concentrated on behaviours that can be called instinctive, or natural, in that they occur in all members of a species under specified circumstances. Their beginning for studying the behaviour of a new species was to construct an
ethogram
An ethogram is a catalogue or inventory of behaviours or actions exhibited by an animal used in ethology.
The behaviours in an ethogram are usually defined to be mutually exclusive and objective, avoiding subjectivity and functional inference as ...
(a description of the main types of behaviour with their frequencies of occurrence). This provided an objective, cumulative database of behaviour, which subsequent researchers could check and supplement.
[
]
Growth of the field
Due to the work of Konrad Lorenz
Konrad Zacharias Lorenz (; 7 November 1903 – 27 February 1989) was an Austrian zoologist, ethologist, and ornithologist. He shared the 1973 Nobel Prize in Physiology or Medicine with Nikolaas Tinbergen and Karl von Frisch. He is often regarded ...
and Niko Tinbergen
Nikolaas "Niko" Tinbergen (; ; 15 April 1907 – 21 December 1988) was a Dutch biologist and ornithologist who shared the 1973 Nobel Prize in Physiology or Medicine with Karl von Frisch and Konrad Lorenz for their discoveries concerning the or ...
, ethology developed strongly in continental Europe during the years prior to World War II
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...
. After the war, Tinbergen moved to the University of Oxford
, mottoeng = The Lord is my light
, established =
, endowment = £6.1 billion (including colleges) (2019)
, budget = £2.145 billion (2019–20)
, chancellor ...
, and ethology became stronger in the UK, with the additional influence of William Thorpe, Robert Hinde
Robert Aubrey Hinde (26 October 1923 – 23 December 2016) was a British zoologist, ethologist and psychologist.Bateson, P., Stevenson-Hinde, J., & Clutton-Brock, T. (2018). Robert Aubrey Hinde CBE. 26 October 1923—23 December 2016. 65, ...
, and Patrick Bateson
Sir Paul Patrick Gordon Bateson, (31 March 1938 – 1 August 2017) was an English biologist with interests in ethology and phenotypic plasticity. Bateson was a professor at the University of Cambridge and served as president of the Zoologi ...
at the Sub-department of Animal Behaviour of the University of Cambridge
, mottoeng = Literal: From here, light and sacred draughts.
Non literal: From this place, we gain enlightenment and precious knowledge.
, established =
, other_name = The Chancellor, Masters and Schola ...
. In this period, too, ethology began to develop strongly in North America
North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...
.
Lorenz, Tinbergen, and von Frisch were jointly awarded the Nobel Prize in Physiology or Medicine
The Nobel Prize in Physiology or Medicine is awarded yearly by the Nobel Assembly at the Karolinska Institute for outstanding discoveries in physiology or medicine. The Nobel Prize is not a single prize, but five separate prizes that, accord ...
in 1973 for their work of developing ethology.
Ethology is now a well-recognized scientific discipline, and has a number of journals covering developments in the subject, such as ''Animal Behaviour
Ethology is the scientific study of animal behaviour, usually with a focus on behaviour under natural conditions, and viewing behaviour as an evolutionarily adaptive trait. Behaviourism as a term also describes the scientific and objectiv ...
'', '' Animal Welfare'', '' Applied Animal Behaviour Science'', ''Animal Cognition
Animal cognition encompasses the mental capacities of non-human animals including insect cognition. The study of animal conditioning and learning used in this field was developed from comparative psychology. It has also been strongly influen ...
'', '' Behaviour'', ''Behavioral Ecology
Behavioral ecology, also spelled behavioural ecology, is the study of the evolutionary basis for animal behavior due to ecological pressures. Behavioral ecology emerged from ethology after Niko Tinbergen outlined four questions to address when ...
'' and '' Ethology: International Journal of Behavioural Biology''. In 1972, th
International Society for Human Ethology
was founded to promote exchange of knowledge and opinions concerning human behaviour gained by applying ethological principles and methods and published their journal,
The Human Ethology Bulletin
'. In 2008, in a paper published in the journal ''Behaviour'', ethologist Peter Verbeek introduced the term "Peace Ethology" as a sub-discipline of Human Ethology that is concerned with issues of human conflict, conflict resolution, reconciliation, war, peacemaking, and peacekeeping behaviour.
Social ethology and recent developments
In 1972, the English
English usually refers to:
* English language
* English people
English may also refer to:
Peoples, culture, and language
* ''English'', an adjective for something of, from, or related to England
** English national ide ...
ethologist John H. Crook distinguished comparative ethology from social ethology, and argued that much of the ethology that had existed so far was really comparative ethology—examining 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.
E. O. Wilson
Edward Osborne Wilson (June 10, 1929 – December 26, 2021) was an American biologist, naturalist, entomologist and writer. According to David Attenborough, Wilson was the world's leading expert in his specialty of myrmecology, the study of an ...
's book '' Sociobiology: The New Synthesis'' appeared in 1975,[ and since that time, the study of behaviour has been much more concerned with social aspects. It has also been driven by the stronger, but more sophisticated, Darwinism associated with Wilson, ]Robert Trivers
Robert Ludlow "Bob" Trivers (; born February 19, 1943) is an American evolutionary biologist and sociobiologist. Trivers proposed the theories of reciprocal altruism (1971), parental investment (1972), facultative sex ratio determination (1973), ...
, and W. D. Hamilton
William Donald Hamilton (1 August 1936 – 7 March 2000) was a British evolutionary biologist, recognised as one of the most significant evolutionary theorists of the 20th century.
Hamilton became known for his theoretical work expounding a ...
. The related development of behavioural ecology
Behavioral ecology, also spelled behavioural ecology, is the study of the evolutionary basis for animal behavior due to ecological pressures. Behavioral ecology emerged from ethology after Niko Tinbergen outlined four questions to address when ...
has also helped transform ethology. Furthermore, a substantial rapprochement with comparative psychology has occurred, so the modern scientific study of behaviour offers a more or less seamless spectrum of approaches: from animal cognition
Animal cognition encompasses the mental capacities of non-human animals including insect cognition. The study of animal conditioning and learning used in this field was developed from comparative psychology. It has also been strongly influen ...
to more traditional comparative psychology, ethology, sociobiology
Sociobiology is a field of biology that aims to examine and explain social behavior in terms of evolution. It draws from disciplines including psychology, ethology, anthropology, evolution, zoology, archaeology, and population genetics. Within ...
, and behavioural ecology. In 2020, Dr. Tobias Starzak and Professor Albert Newen from the Institute of Philosophy II at the Ruhr University Bochum
The Ruhr University Bochum (, ) is a public research university located in the southern hills of the central Ruhr area, Bochum, Germany. It was founded in 1962 as the first new public university in Germany after World War II. Instruction began in ...
postulated that animals may have beliefs.
Relationship with comparative psychology
Comparative psychology also studies animal behaviour, but, as opposed to ethology, is construed as a sub-topic of psychology
Psychology is the scientific study of mind and behavior. Psychology includes the study of conscious and unconscious phenomena, including feelings and thoughts. It is an academic discipline of immense scope, crossing the boundaries betwe ...
rather than as one of biology
Biology is the scientific study of life. It is a natural science with a broad scope but has several unifying themes that tie it together as a single, coherent field. For instance, all organisms are made up of cells that process hereditary i ...
. Historically, where comparative psychology has included research on animal behaviour in the context of what is known about human psychology, ethology involves research on animal behaviour in the context of what is known about animal anatomy
Anatomy () is the branch of biology concerned with the study of the structure of organisms and their parts. Anatomy is a branch of natural science that deals with the structural organization of living things. It is an old science, having its ...
, physiology
Physiology (; ) is the scientific study of functions and mechanisms in a living system. As a sub-discipline of biology, physiology focuses on how organisms, organ systems, individual organs, cells, and biomolecules carry out the chemical ...
, neurobiology
Neuroscience is the scientific study of the nervous system (the brain, spinal cord, and peripheral nervous system), its functions and disorders. It is a multidisciplinary science that combines physiology, anatomy, molecular biology, developme ...
, and phylogenetic
In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups o ...
history. Furthermore, early comparative psychologists concentrated on the study of learning and tended to research behaviour in artificial situations, whereas early ethologists concentrated on behaviour in natural situations, tending to describe it as instinctive.
The two approaches are complementary rather than competitive, but they do result in different perspectives, and occasionally conflicts of opinion about matters of substance. In addition, for most of the twentieth century, comparative psychology developed most strongly in North America
North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...
, while ethology was stronger in Europe
Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...
. From a practical standpoint, early comparative psychologists concentrated on gaining extensive knowledge of the behaviour of very few species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...
. Ethologists were more interested in understanding behaviour across a wide range of species to facilitate principled comparisons across taxonomic groups. Ethologists have made much more use of such cross-species comparisons than comparative psychologists have.
Instinct
The Merriam-Webster dictionary defines instinct
Instinct is the inherent inclination of a living organism towards a particular complex behaviour, containing both innate (inborn) and learned elements. The simplest example of an instinctive behaviour is a fixed action pattern (FAP), in which a v ...
as "A largely inheritable and unalterable tendency of an organism to make a complex and specific response to environmental stimuli without involving reason".
Fixed action patterns
An important development, associated with the name of Konrad Lorenz though probably due more to his teacher, Oskar Heinroth, was the identification of fixed action pattern A fixed action pattern is an ethological term describing an instinctive behavioral sequence that is highly stereotyped and species-characteristic. Fixed action patterns are said to be produced by the innate releasing mechanism, a "hard-wired" neura ...
s. Lorenz popularized these as instinctive responses that would occur reliably in the presence of identifiable stimuli called sign stimuli or "releasing stimuli". Fixed action patterns are now considered to be instinctive behavioural sequences that are relatively invariant within the species and that almost inevitably run to completion.
One example of a releaser is the beak
The beak, bill, or rostrum is an external anatomical structure found mostly in birds, but also in turtles, non-avian dinosaurs and a few mammals. A beak is used for eating, preening, manipulating objects, killing prey, fighting, probing for food ...
movements of many bird species performed by newly hatched chicks, which stimulates the mother to regurgitate food for her offspring. Other examples are the classic studies by Tinbergen on the egg-retrieval behaviour and the effects of a " supernormal stimulus" on the behaviour of graylag geese
The greylag goose or graylag goose (''Anser anser'') is a species of large goose in the waterfowl family Anatidae and the type species of the genus '' Anser''. It has mottled and barred grey and white plumage and an orange beak and pink legs. A ...
.
One investigation of this kind was the study of the waggle dance
Waggle dance is a term used in beekeeping and ethology for a particular figure-eight dance of the honey bee. By performing this dance, successful foragers can share information about the direction and distance to patches of flowers yielding nect ...
("dance language") in bee communication by Karl von Frisch
Karl Ritter von Frisch, (20 November 1886 – 12 June 1982) was a German-Austrian ethologist who received the Nobel Prize in Physiology or Medicine in 1973, along with Nikolaas Tinbergen and Konrad Lorenz.
His work centered on investigations o ...
.
Learning
Habituation
Habituation is a simple form of learning and occurs in many animal taxa. It is the process whereby an animal ceases responding to a stimulus. Often, the response is an innate behaviour. Essentially, the animal learns not to respond to irrelevant stimuli. For example, prairie dogs (''Cynomys ludovicianus'') give alarm calls when predators approach, causing all individuals in the group to quickly scramble down burrows. When prairie dog towns are located near trails used by humans, giving alarm calls every time a person walks by is expensive in terms of time and energy. Habituation to humans is therefore an important adaptation in this context.
Associative learning
Associative learning in animal behaviour is any learning process in which a new response becomes associated with a particular stimulus. The first studies of associative learning were made by Russian physiologist Ivan Pavlov
Ivan Petrovich Pavlov ( rus, Ива́н Петро́вич Па́влов, , p=ɪˈvan pʲɪˈtrovʲɪtɕ ˈpavləf, a=Ru-Ivan_Petrovich_Pavlov.ogg; 27 February 1936), was a Russian and Soviet experimental neurologist, psychologist and physio ...
, who observed that dogs trained to associate food with the ringing of a bell would salivate on hearing the bell.
Imprinting
Imprinting enables the young to discriminate the members of their own species, vital for reproductive success. This important type of learning only takes place in a very limited period of time. Konrad Lorenz
Konrad Zacharias Lorenz (; 7 November 1903 – 27 February 1989) was an Austrian zoologist, ethologist, and ornithologist. He shared the 1973 Nobel Prize in Physiology or Medicine with Nikolaas Tinbergen and Karl von Frisch. He is often regarded ...
observed that the young of birds such as geese
A goose ( : geese) is a bird of any of several waterfowl species in the family Anatidae. This group comprises the genera '' Anser'' (the grey geese and white geese) and ''Branta'' (the black geese). Some other birds, mostly related to the she ...
and chicken
The chicken (''Gallus gallus domesticus'') is a domesticated junglefowl species, with attributes of wild species such as the grey and the Ceylon junglefowl that are originally from Southeastern Asia. Rooster or cock is a term for an adu ...
s followed their mothers spontaneously 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 were presented during a critical period that continued for a few days after hatching.
Cultural learning
Observational learning
Imitation
Imitation
Imitation (from Latin ''imitatio'', "a copying, imitation") is a behavior whereby an individual observes and replicates another's behavior. Imitation is also a form of that leads to the "development of traditions, and ultimately our culture. ...
is an advanced behaviour whereby an animal observes and exactly replicates the behaviour of another.
The National Institutes of Health reported that capuchin monkeys preferred the company of researchers who imitated them to that of researchers who did not. The monkeys not only spent more time with their imitators but also preferred to engage in a simple task with them even when provided with the option of performing the same task with a non-imitator. Imitation has been observed in recent research on chimpanzees; not only did these chimps copy the actions of another individual, when given a choice, the chimps preferred to imitate the actions of the higher-ranking elder chimpanzee as opposed to the lower-ranking young chimpanzee.
Stimulus and local enhancement
There are various ways animals can learn using observational learning but without the process of imitation. One of these is ''stimulus enhancement'' in which individuals become interested in an object as the result of observing others interacting with the object. Increased interest in an object can result in object manipulation which allows for new object-related behaviours by trial-and-error learning. Haggerty (1909) devised an experiment in which a monkey climbed up the side of a cage, placed its arm into a wooden chute, and pulled a rope in the chute to release food. Another monkey was provided an opportunity to obtain the food after watching a monkey go through this process on four occasions. The monkey performed a different method and finally succeeded after trial-and-error. Another example familiar to some cat and dog owners is the ability of their animals to open doors. The action of humans operating the handle to open the door results in the animals becoming interested in the handle and then by trial-and-error, they learn to operate the handle and open the door.
In local enhancement, a demonstrator attracts an observer's attention to a particular location. Local enhancement has been observed to transmit foraging information among birds, rats and pigs. The stingless bee (''Trigona corvina
''Trigona corvina'' ( Cockerell, 1913) is a species of stingless bee that lives primarily in Central and South America. In Panama, they are sometimes known as zagañas. They live in protective nests high in the trees, but they can be extremely a ...
'') uses local enhancement to locate other members of their colony and food resources.
Social transmission
A well-documented example of social transmission of a behaviour occurred in a group of macaques on Hachijojima Island, Japan. The macaques lived in the inland forest until the 1960s, when a group of researchers started giving them potatoes on the beach: soon, they started venturing onto the beach, picking the potatoes from the sand, and cleaning and eating them. About one year later, an individual was observed bringing a potato to the sea, putting it into the water with one hand, and cleaning it with the other. This behaviour was soon expressed by the individuals living in contact with her; when they gave birth, this behaviour was also expressed by their young - a form of social transmission.
Teaching
Teaching is a highly specialized aspect of learning in which the "teacher" (demonstrator) adjusts their behaviour to increase the probability of the "pupil" (observer) achieving the desired end-result of the behaviour. For example, orca
The orca or killer whale (''Orcinus orca'') is a toothed whale belonging to the oceanic dolphin family, of which it is the largest member. It is the only extant species in the genus '' Orcinus'' and is recognizable by its black-and-white ...
s are known to intentionally beach themselves to catch pinniped
Pinnipeds (pronounced ), commonly known as seals, are a widely range (biology), distributed and diverse clade of carnivorous, fin-footed, semiaquatic, mostly marine mammal, marine mammals. They comprise the extant taxon, extant family (biology ...
prey. Mother orcas teach their young to catch pinnipeds by pushing them onto the shore and encouraging them to attack the prey. Because the mother orca is altering her behaviour to help her offspring learn to catch prey, this is evidence of teaching.[ Teaching is not limited to mammals. Many insects, for example, have been observed demonstrating various forms of teaching to obtain food. ]Ant
Ants are eusocial insects of the family Formicidae and, along with the related wasps and bees, belong to the order Hymenoptera. Ants evolved from vespoid wasp ancestors in the Cretaceous period. More than 13,800 of an estimated total of ...
s, for example, will guide each other to food sources through a process called "tandem running
Tandem running is a pair movement coordination observed in ants and termites.
In ants, tandem running is used for social learning, by which one ant leads another native ant from the nest to the food source it has found. Tandem running is also us ...
," in which an ant will guide a companion ant to a source of food. It has been suggested that the pupil ant is able to learn this route to obtain food in the future or teach the route to other ants. This behaviour of teaching is also exemplified by crows, specifically New Caledonian crow
The New Caledonian crow (''Corvus moneduloides'') is a medium-sized member of the family Corvidae, native to New Caledonia. The bird is often referred to as the 'qua-qua' due to its distinctive call. It eats a wide range of food, including man ...
s. The adults (whether individual or in families) teach their young adolescent offspring how to construct and utilize tools. For example, '' Pandanus'' branches are used to extract insects and other larvae from holes within trees.
Mating and the fight for supremacy
Individual reproduction
Reproduction (or procreation or breeding) is the biological process by which new individual organisms – "offspring" – are produced from their "parent" or parents. Reproduction is a fundamental feature of all known life; each individual or ...
is the most important phase in the proliferation of individuals or genes within a species: for this reason, there exist complex mating
In biology, mating is the pairing of either opposite-sex or hermaphroditic organisms for the purposes of sexual reproduction. ''Fertilization'' is the fusion of two gametes. ''Copulation'' is the union of the sex organs of two sexually reproduc ...
ritual
A ritual is a sequence of activities involving gestures, words, actions, or objects, performed according to a set sequence. Rituals may be prescribed by the traditions of a community, including a religious community. Rituals are characterized, b ...
s, which can be very complex even if they are often regarded as fixed action patterns. The stickleback's complex mating ritual, studied by Tinbergen, is regarded as a notable example.
Often in social life, animals fight for the right to reproduce, as well as social supremacy. A common example of fighting for social and sexual supremacy is the so-called pecking order
In biology, a dominance hierarchy (formerly and colloquially called a pecking order) is a type of social hierarchy that arises when members of animal social groups interact, creating a ranking system. A dominant higher-ranking individual is so ...
among poultry
Poultry () are domesticated birds kept by humans for their eggs, their meat or their feathers. These birds are most typically members of the superorder Galloanserae (fowl), especially the order Galliformes (which includes chickens, quails, ...
. Every time a group of poultry cohabitate for a certain time length, they establish a pecking order. In these groups, one chicken dominates the others and can peck without being pecked. A second chicken can peck all the others except the first, and so on. Chickens higher in the pecking order may at times be distinguished by their healthier appearance when compared to lower level chickens. While the pecking order is establishing, frequent and violent fights can happen, but once established, it is broken only when other individuals enter the group, in which case the pecking order re-establishes from scratch.
Living in groups
Several animal species, including humans, tend to live in groups. Group size
Many animals, including humans, tend to live in groups, herds, flocks, bands, packs, shoals, or colonies (hereafter: groups) of conspecific individuals. The size of these groups, as expressed by the number of people/etc in a group such as eight g ...
is a major aspect of their social environment. Social life is probably a complex and effective survival strategy. It may be regarded as a sort of symbiosis
Symbiosis (from Greek , , "living together", from , , "together", and , bíōsis, "living") is any type of a close and long-term biological interaction between two different biological organisms, be it mutualistic, commensalistic, or parasit ...
among individuals of the same species: a society
A society is a group of individuals involved in persistent social interaction, or a large social group sharing the same spatial or social territory, typically subject to the same political authority and dominant cultural expectations. Socie ...
is composed of a group of individuals belonging to the same species living within well-defined rules on food
Food is any substance consumed by an organism for nutritional support. Food is usually of plant, animal, or fungal origin, and contains essential nutrients, such as carbohydrates, fats, proteins, vitamins, or minerals. The substance is inge ...
management, role assignments and reciprocal dependence.
When biologist
A biologist is a scientist who conducts research in biology. Biologists are interested in studying life on Earth, whether it is an individual Cell (biology), cell, a multicellular organism, or a Community (ecology), community of Biological inter ...
s interested in evolution theory
Evolution is change in the heritable characteristics of biological populations over successive generations. These characteristics are the expressions of genes, which are passed on from parent to offspring during reproduction. Variation t ...
first started examining social behaviour, some apparently unanswerable questions arose, such as how the birth of sterile caste
Caste is a form of social stratification characterised by endogamy, hereditary transmission of a style of life which often includes an occupation, ritual status in a hierarchy, and customary social interaction and exclusion based on cultura ...
s, like in bees, could be explained through an evolving mechanism that emphasizes the reproductive success of as many individuals as possible, or why, amongst animals living in small groups like squirrels, an individual would risk its own life to save the rest of the group. These behaviours may be examples of altruism. Of course, not all behaviours are altruistic, as indicated by the table below. For example, revengeful behaviour was at one point claimed to have been observed exclusively in ''Homo sapiens
Humans (''Homo sapiens'') are the most abundant and widespread species of primate, characterized by bipedalism and exceptional cognitive skills due to a large and complex brain. This has enabled the development of advanced tools, culture, ...
''. However, other species have been reported to be vengeful including chimpanzees, as well as anecdotal reports of vengeful camels.
Altruistic
Altruism is the principle and moral practice of concern for the welfare and/or happiness of other human beings or animals, resulting in a quality of life both material and spiritual. It is a traditional virtue in many cultures and a core asp ...
behaviour has been explained by the gene-centred view of evolution.
Benefits and costs of group living
One advantage of group living can be decreased predation. If the number of predator attacks stays the same despite increasing prey group size, each prey may have a reduced risk of predator attacks through the dilution effect. Further, according to the selfish herd theory
The selfish herd theory states that individuals within a population attempt to reduce their predation risk by putting other conspecifics between themselves and predators. A key element in the theory is the domain of danger, the area of ground in wh ...
, the fitness benefits associated with group living vary depending on the location of an individual within the group. The theory suggests that conspecifics positioned at the centre of a group will reduce the likelihood predations while those at the periphery will become more vulnerable to attack. Additionally, a predator that is confused by a mass of individuals can find it more difficult to single out one target. For this reason, the zebra's stripes offer not only camouflage in a habitat of tall grasses, but also the advantage of blending into a herd of other zebras. In groups, prey can also actively reduce their predation risk through more effective defence tactics, or through earlier detection of predators through increased vigilance.[
Another advantage of group living can be an increased ability to forage for food. Group members may exchange information about food sources between one another, facilitating the process of ]resource location
Resource refers to all the materials available in our environment which are technologically accessible, economically feasible and culturally sustainable and help us to satisfy our needs and wants. Resources can broadly be classified upon their ...
.[ Honeybees are a notable example of this, using the ]waggle dance
Waggle dance is a term used in beekeeping and ethology for a particular figure-eight dance of the honey bee. By performing this dance, successful foragers can share information about the direction and distance to patches of flowers yielding nect ...
to communicate the location of flowers to the rest of their hive. Predators also receive benefits from hunting in groups, through using better strategies and being able to take down larger prey.[
Some disadvantages accompany living in groups. Living in close proximity to other animals can facilitate the transmission of parasites and disease, and groups that are too large may also experience greater competition for resources and mates.
]
Group size
Theoretically, social animals should have optimal group sizes that maximize the benefits and minimize the costs of group living. However, in nature, most groups are stable at slightly larger than optimal sizes.[ Because it generally benefits an individual to join an optimally-sized group, despite slightly decreasing the advantage for all members, groups may continue to increase in size until it is more advantageous to remain alone than to join an overly full group.
]
Tinbergen's four questions for ethologists
Niko Tinbergen argued that ethology always needed to include four kinds of explanation in any instance of behaviour:
* Function – How does the behaviour affect the animal's chances of survival and reproduction? Why does the animal respond that way instead of some other way?
* Causation – What are the stimuli that elicit the response, and how has it been modified by recent learning?
* Development – How does the behaviour change with age, and what early experiences are necessary for the animal to display the behaviour?
* Evolutionary history – How does the behaviour compare with similar behaviour in related species, and how might it have begun through the process of phylogeny
A phylogenetic tree (also phylogeny or evolutionary tree Felsenstein J. (2004). ''Inferring Phylogenies'' Sinauer Associates: Sunderland, MA.) is a branching diagram or a tree showing the evolutionary relationships among various biological spe ...
?
These explanations are complementary rather than mutually exclusive—all instances of behaviour require an explanation at each of these four levels. For example, the function of eating is to acquire nutrients (which ultimately aids survival and reproduction), but the immediate cause of eating is hunger (causation). Hunger and eating are evolutionarily ancient and are found in many species (evolutionary history), and develop early within an organism's lifespan (development). It is easy to confuse such questions—for example, to argue that people eat because they're hungry and not to acquire nutrients—without realizing that the reason people experience hunger is because it causes them to acquire nutrients.[Barrett et al. (2002) Human Evolutionary Psychology. Princeton University Press.]
See also
* Anthrozoology
Anthrozoology, also known as human–nonhuman-animal studies (HAS), is the subset of ethnobiology that deals with interactions between humans and other animals. It is an interdisciplinary field that overlaps with other disciplines including a ...
* Behavioral ecology
Behavioral ecology, also spelled behavioural ecology, is the study of the evolutionary basis for animal behavior due to ecological pressures. Behavioral ecology emerged from ethology after Niko Tinbergen outlined four questions to address when ...
* Cognitive ethology
Cognitive ethology is a branch of ethology concerned with the influence of conscious awareness and intention on the behaviour of an animal. Donald Griffin, a zoology professor in the United States, set up the foundations for researches in the cogn ...
* Deception in animals
Deception in animals is the transmission of misinformation by one animal to another, of the same or different species, in a way that propagates beliefs that are not true.
Mimicry and camouflage enable animals to appear to be other than they are ...
* Human ethology
Human ethology is the study of human behavior.
Ethology as a discipline is generally thought of as a sub-category of biology, though psychological theories have been developed based on ethological ideas (e.g. sociobiology, evolutionary psychology, ...
* List of abnormal behaviours in animals Abnormal behaviour in animals can be defined in several ways. Statistically, abnormal is when the occurrence, frequency or intensity of a behaviour varies statistically significantly, either more or less, from the normal value. This means that th ...
References
Further reading
Burkhardt, Richard W. Jr. "On the Emergence of Ethology as a Scientific Discipline." Conspectus of History 1.7 (1981).
External links
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Ethology
Ethology is the scientific study of animal behaviour, usually with a focus on behaviour under natural conditions, and viewing behaviour as an evolutionarily adaptive trait. Behaviourism as a term also describes the scientific and objecti ...
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