Zoologists recognised that behaviour patterns are species specific, and can be used as taxonomical traits.

Whitman: pigeon taxonomy
Heinroth: duck taxonomy
They described behaviour precisely but had no theory to explain it. Instinct is not an explanation. Is there sepcific instincts behing every single movement?

Different approaches

Reflex theory (Pavlov)

• Few unconditioned stimuli
• Few unconditioned response
• Any UC sitmus + CS = learns about any new stimulus
  

Behaviorism

• Few US
• Few UR
• Trial and error + US = learns any new behaviour
  

Zoologists

• Plenty of US and UR
• Few novel behaviour
• species specific behaviour
• even learning is species specific

Ethologists

assumed that species specific behaviour patterns are controlled by specific brain areas. Simple behaviour is trigered by specific stimulus -> brain centre -> response

Kinesis (definition)

Stimulus -> response
Direction: independent of stimulus

Examples:

• Paramecium bumps into an object, swims backwards - direction is changed - then swims forward.
• Woodlice prefer dark, damp places, but do not have the capacity to search for such environment. In unfavourable conditions woodlice move fast. In damper and darker area they slow down. In optimal area they stop moving.
• Movement behaviour and video tracking of Milnesium tardigradum [full paper]

Taxis

Direction: depends on stimulus

Examples:

• Fly larvae prefer dark places. Swiings its head from side zo side. If senses light by one eye would turn its body contralaterally.
• Silkmoth females produce bombykol (the first pheromone characerised chemically), males
  approach the females
• Attraction of the oriental fruit fly, Dacus dorsalis, to methyl eugenol
  and related olfactory stimulants [pdf]
• An aerotaxis transducer gene from Pseudomonas putida [html]
  

Fixed Action Patterns (FAPs)

FAP is stereotypic behaviour elicited by specific stimuls (key stimulus), its form is fixed and species specific. Once started it will be finished and can occur without the presence of the appropriate stimulus (vacuum activity).

One example for FAP is the egg rolling behaviour of greylag geese studied by Lorenz (on the left) and Tinbergen (on the right) together.

FAP was a key concept in early ethology. First of all demonstrating a large number and variety of unlearned behaviour in many species helped ethologists to win the battle with behaviourists who proposed that most behaviour is learned. Also, the suggestion that FAPs are controlled by hardwired brain circuitry helped ethologists to propose mechanism for instinctive behaviour.

Today, however, the term FAP is seldom used. Critics of the term state that most behaviours are not so much fixed as previously thought, and are influenced by environmental stimuli and experience (see Box 3.2 p. 122 in Barnard's). The fixed form of FAPs, however, is not so much stressed in the original German expression (angeboren Bewegungsweisen Erbkoordination) which literally means innate movement coordination. But then "innate" is also problematic, many behaviour patterns are the result of interaction between unlearned and learned components. George Barlow in 1968 suggested to replace the term FAP with Modal Action Pattern (MAP).

Examples:

• The escape behaviour of the marine Mollusc Tritonia is trigerred by an approaching starfish, the mollusk's predator. It consists of several dorsal and ventral rhythmic flexions which once elicited runs into complition even in the absance of relevant stimulus.
• This study analysed the tongue-protrusion capture of prey in a lizard species and concludes that it is not a typical fixed-action pattern, because of it's variability in performance and duration [full]
• Sequential super-stereotypy of an instinctive fixed action pattern in hyper-dopaminergic mutant mice: a model of obsessive compulsive disorder and Tourette's [full]

Whether we call behaviour patterns FAPs or MAPs is not important. What is important whether behaviour consists of natural units or not. Ethologists assume that behaviour is built of units therefore behaviour can be described by the sequence of such elements. This is not merely a practical issue, because by studying such sequences we can understand the organisation and evolution of behavoiour.

Examples:

• Structure and composition of the courtship phenotype in the bird of paradise Parotia lawesii (Aves: Paradisaeidae) [pdf]
• Evolution of the courtship phenotype in the bird of paradise genus Parotia (Aves: Paradisaeidae): homology, phylogeny, and modularity [pdf]

What kind of stimuli can elicit FAPs?

There were two hypotheses: animals either respond to a whole pattern or to specific traits of a pattern. In other words is the whole greater than the sum of the parts - as Gestalt psychology suggested [wiki], or the parts independently affect behaviour.

Niko Tinbergen developed an elegant method to systematically study this question (Tinbergen 1948. pdf). Basically, he constructed a life-like dummy of the stimulus he analysed and then systematically changed it to see which components trigger the FAP. For example, a life-like male stickleback dummy without red colouration underneath does not provoke aggression. Dummies of allmost any size or shape with red "belly" will elicit aggression in male sticklebacks.

Chicks pecked more at the red patch as illustrated by Tinbergen in his textbook.

Well, actually, the chicks pecked at the black patch more than on the red one. Tinbergen reasoned that was an artifact produced by the experimental design: he presented the modell with the red patch more often than the other modells therefore the chicks might have habituated to it. Carel ten Cate et al. (2009. abstract, pdf) repeated the experiments . When the modells were presented in a balanced way the red patch was preferred as predicted by Tinbergen and Perdeck [pdf].

The evolution of the gull chick colour preference from the original report to the textbooks (ten Cate 2009. pdf)

Oppinions about Tinbergen's experiment [Nature]

Key stimulus: contrast

Black and white patch on grey beak are preferred. Conrast itself is important.

Key stimulus: colour of the beaks

Red beaks over the natural yellow are preferred (!)

Key stimulus: movement

The moving modell even without the red patch elicits more pecking than the stationary head with patch. The bill is more important than the head. A yellow stick with three red lines is more affective than the realistic modell.

Key stimulus: position of the patch

The dot on the underside of the lower mandibule elicits more pecking than the dot on the forehead. Tinbergen concluded that the chikcs are guided by innate template recognition

Hailman did a series of experiments on herring and laughing gull chicks and found that the chicks do not recognise the "template" as Tinbergen suggested, but simply are attracted to the red patch. As the models presented were swinging on a pendulum, the patch on the bill moved faster than the patch on the forehead. Hailman showed that the speed of the patch rather than the configuration is important.

Hailman main contribution to the gull chick paradigm was the recognition that experience and learning shape the pecking response (Hailman 1969. abstract). Chicks indeed except any oddly shaped model with a beak, or even a beak alone, however, only for a few days after hatching. Later the chicks react only to models closely resembling their parents. The begging behaviouir also changes with age. First the chicks peck at the beak, later they rotate theirr head and grasp the beak (as seen in the video above). Hailman raised some chicks in the dark and handfed them so the chicks had no experience with pecking at or grasping the bill of the parents. At the age when untreated chicks could perform rotating and grasping Hailman tested the dark reared chicks and found they were not able to do so.

Tinbergen found that gull chicks prefer a model resembling their own species and suggested that recognition is unlearned. Hailman had similar experience with 8 day old chicks, however, he found no preference whatsoever right after hatching. Therefore preference of own species is not innate, chicks learn to recognise and prefer the parents (to see figure click here - great site on early ethology).

Supernormal stimulus

A yellow stick with three red lines elicits more pecking than the natural head. Greylag geese prefer to roll bigger than normal egg.

The European oystercatcher (Haematopus ostralegus) retreives an egg so large, she can not incubate it.

These are examples for supernormal stimuli i.e. a stimuli which elicit bigger response than the natural stimuli. Animals in nature seldom encounter bigger than life stimulus therefore to set an upper limit by the nervouos system in most cases is unimportant.

However, attraction to supernormal stimuli can be exploited in many ways. Even when chicks of nest prasite cuckoos grow larger than foster mother, adults keep on feeding it (Grim and Honza 2001. pdf).

Humans tend to exaggerate pleasing stimuli and diminish obnoxious characteristics from food to advertisement. For example, sweetness of fruits or roots were indicators of their energy content, therefore preference for sweet taste was adaptive for early humans. Today industry is capable to produce concentrated sugar, humans consume of it in unhealthy amounts. The ability to sense sugar must be crucial for some species as indicated by the fact that sugar is highly addictive (Lenoir et al. 2007 html). Do not follow your instinct (conversation Barrett html)

Examples for key stimuli

Europen robin (Erithacus rubecula) attacks anything with a red patch on it.
A newly hatched chick approaches any moving object.
"Besotted beetles are dying while trying to get it on with discarded brown beer bottles" here

Analysis of key stimuli

What are the components of the key stimuli? Do they act independently or in interaction?
Tinbergen exploited the egg retreival behaviour to study preference for shape, size, colour and pattern. en: kísérlet (repeated later by Baerends & Kruijt)

Eggs on the horizontal lines are identical in shape and colouration and different only in size. Larger eggs are preferred over smaller one. Vertical lines connect equally preferred eggs. Therefore preference can be directly estimated. For example vertical eggs connected by vertical line at 1.8 are equally preferred meaning that for the same preference larger egg is needed if unspeckled. Green speckled eggs are preferred over natural colouration. For full explanation follow link and click at page to open it. For a good quality figure visit here.

Affectivity of the components of the stimulus pattern seem to add up independently (heterogenous summation).

Interesting: Richard Dawkins talking with ethologist Aubrey Manning