lesson7: communication

An action performed by an animal that transmits information and modifies the behavior of another animal.

When the behavior of one animal (producer or transmitter) affects the behavior of another (receiver) and

• there is a social interaction between their actions.

The message must be meaningful.

• Genuine communication

• Fortuitous communication

• Both the producer and the receiver must obtain a direct or indirect benefit;

• otherwise the signal would not be emitted or would be ignored.

Some signals benefit the producer and take advantage of the receiver to deceive or manipulate.

A form of deception in which the producer deliberately manipulates the receiver.

Deception only works when it is rare.

Producer – Message (code) – Transmission channel – Receiver – Feedback – Behavior – Context

Any behavior that transmits information (it can have other functions).

• Discrete (dichotomous) signals

• Gradual (continuous) signals

All-or-nothing signals with no variation in intensity.

Blinks of fireflies.

The intensity of the signal varies depending on the motivation of the animal that produces it.

Canids: movement of the ears and folding of the lips (showing teeth).

• Increased fear signal

• Increased aggressive signal strength

They are usually species-specific, clear (not ambiguous), and economical.

1. Expressive or autonomous responses

2. Intentional movements

3. Displays or exhibitions

Automatic, involuntary responses controlled by the autonomic nervous system.

Color changes, pilo-erection, ridge elevation.

Information about the state of the individual and its reaction to the situation.

Voluntary actions aimed at a goal and clearly related to the effect they want to achieve.

Threat, appeasement or conciliation, courtship, territorial defence, regrouping.

The outstretched hand in chimpanzees as a begging gesture.

Signals with an exclusively communicative function.

1. Exaggerated and stereotyped movements

2. Highlight colours or special body structures

3. Sequential structure

They evolved through a process of ritualization (origin: displaced behaviours).

Movements with typical intensity, specific duration, and invariable sequence, independent of motivation level.

Movements highlight perceptually striking aspects such as colors or structures.

Repetition of movements and sequences.

A limited number (e.g., fish ≈ 10, macaques ≈ 40).

Does a limited number of signals imply a limited number of messages? -> NO

• Spatial and temporal context

• Producer characteristics

• Signal strength

• Signal duration

• Combination with other signals

• Order in signal transmission (syntax)

Nonverbal codes that carry meaning, such as invitations to play or signalling hierarchy status.

Visual, chemical, acoustic (hearing), tactile, electric.

Scope in space,

transmission speed,

ability to overcome obstacles,

use in the dark,

decay in time,

possibility to locate the producer,

energy cost.

Fast and directional information.

Depends on light and receiver orientation, does not overcome obstacles, does not last in time.

Sound vibrations transmitted through air, water, or substrate.

Advantages:

fast, long-distance, no light needed.

Disadvantages:

does not last, inaccurate spatial information, nonspecific receptors.

Direct contact of body surfaces.

Greetings, appeasement, comfort, recognition, bonding.

1. Does not last over time

2. Requires physical proximity

3. Does not overcome obstacles

4. Inaccurate structure

5. Very limited signal range

Diffusion of substances (pheromones).

Advantages:

• lasts over time, not affected by obstacles, low energy cost.

Disadvantages:

• slow, inaccurate spatial information, hard to change message.

Chemicals secreted outside the body that act as signals modifying the behavior of conspecifics.

Combining signals from different channels to increase effectiveness.

Any interference affecting message transmission.

Repeated transmission compensates for noise.

Systems that identify the individual (species, group, age, sex, hierarchy, individual).

Systems related to meaning,

• such as alarm, food tracking, care of infants, courtship, social regulation, recruitment.

Mostly species-specific codes.

Communication based on the intersection of intraspecific codes of different species.

Less complex signals, such as alarm calls to a common predator.

Strictly interspecific signals that ensure exclusivity (e.g. touches by cleaner fish).

Phylogenetic proximity (behavioral homology)

and evolutionary convergence (ecological factors).

• Chemical: Wide

• Acoustic: Wide

• Visual: Medium

• Tactile: Limited

• Chemical: Slow

• Acoustic: Fast

• Visual: Fast

• Tactile: Fast

1. Chemical: Yes

2. Acoustic: Yes

3. Visual: No

4. Tactile: No

1. Chemical: Yes

2. Acoustic: Yes

3. Visual: No (*!)

4. Tactile: Yes

• Chemical: Slow

• Acoustic: Fast

• Visual: Fast

• Tactile: Fast

• Chemical: Difficult

• Acoustic: Easy

• Visual: Easy

• Tactile: Easy

1. Chemical: Low

2. Acoustic: High

3. Visual: Medium

4. Tactile: Low