Communication Flashcards
Lecture 3
Define communication (Krebs & Davies, 1993)
The process in which actors use specially designed signals or displays to modify the behaviour of reactors.
How did Darwin define communication?
‘The expression of the emotions in man and animals’
Human communication is often ________.
intentional
Name the different ways to communicate
Acoustic, visual, tactile, olfactory
What types of communication is particularly relevant for humans?
Tactile communication is used for managing out social relationships between close social partners and vocalisation is extremely important to use and even non-verbal vocalisation such as laughter or sobbing is important.
What types of signal have a long range?
Olfactory and auditory
What types of communication have a slow rate of change of signal?
Olfactory
What types of signals have a good ability to go past obstacles?
Olfactory and auditory
What types of signals have a poor ability to go past obstacles?
Visual and tactile
What type of signal has variable locatability?
olfactory
What type of signal has medium locatability?
auditory
What type of signal has high locatability?
visual and tactile
What types of signal have low energetic costs?
Olfactory, visual, tactile
What types of signal have high energetic costs?
auditory
What types of communication have a fast rate of change of signal?
auditory, visual and tactile
What type of signal has a medium range?
visual
What type of signal has a short range?
tactile
Explain how Leptothorax ants use communication ?
The ants feed on large dead beetles that need two ants to carry it. The ants go back to the nest arm recruit another ant by regurgitation (chemical signal). The helper is lead to the food site by ‘tandem running’, the antennae rests on the abdomen. (tactile)
Explain how fire ants use communication ?
The ants feed on large mobile prey and need several other ants to carry their prey. The ants leave a scent trail (Chemical) to and from the moving prey. The chemical signal disperses quickly so the trail keeps up with the prey.
How do Hyenas use communication?
Hyenas use scent marking which is a chemical signals . There are two compounds, one white and one black. The black compound disperses after a short time potentially to warn pack members that the area has been foraged recently . Meanwhile the white paste persists for longer in order to be a long-term territorial marker. Function dictates the design of the signal.
What does the signal type depend on?
Need and function as well as environmental constraints. The senses of the RECEIVER also constrain the evolution of the signal. (Guildford & Dawkins, 1993)
Explain receiver constraints
There is a conflict between intended and non-intended receivers . Some signals may be detectable to predators. This is addressed through the evolution of undetectable signals such as ‘private colouration’ which have been favoured by evolution.
Explain targeted communication
Used to combat receiver constraints. Behavioural displays such as
- birds of paradise - visual colour couples with courtship dance
- anolid lizards - bright colour hidden in flat of skin
- visual signals but not always ‘‘switched on’’
How do signals evolve?
Signals evolve from existing behaviour which tap into receiver senses. Receivers who respond to behaviour BEFORE it happens will be favoured by evolution because it will reduce the likelihood of an attack and its associated costs (injury).
Give examples of intention movements
dog about to jump - indicating that the dog wants to play
Wing flick as a bird prepares to take off . If produced early enough before taking off, other birds can use this information and coordinate their behaviour .
Explain displacement activities
Seemingly irrelevant actions associated with courtship, threat displays, territorial. behaviour etc.
What is ritualisation?
Intention movements or displacement activities become ritualised if they improve signal function of a display. Behaviours become highly stereotyped, repetitive, exaggerated and augmented by physical changes to aid signal.
What are the three hypothesis about ritualisation
- reduction of ambiguity
- manipulation
- honesty
Explain ‘reduction of ambiguity’ as a hypothesis of ritualisation
Ritualised signals may be less ambiguous and greater clarity of signal. Increased clarity reduces the information about motivational state of the actor. This doesn’t seem like a good thing but it is because if if there is no information about the sender then there is no information regarding the physical/ emotional state. If you are small, nobody will know.
Explain ‘manipulation’ as a hypothesis of ritualisation
Signallers must benefit from signally. An actor manipulates the senses of the receiver via ritualisation, the receiver evolves strategies to avoid this.
Give examples of manipulation
Batesian mimicry
- harmless animals evolve colouration similar to poisonous animals
Deception
- cuckoo eggs
- Drongo false alarms
Explain ‘honesty’ as a hypothesis of ritualisation
Ritualisation allows signals to become reliable signals of quality. Only honest signals will prevail (others will die out) e.g ‘Slotting’ in gazelles.
What are signals constrained by?
- Senses of intended receivers
- Pressure from unintended receivers
- Need for specificity of signals
- Evolutionary arms races with “cheats” engaging in deception
- Consequent preferences for honest
Summarise the communication topic.
Communication is important. The function, environment and the receiver should always be considered when considering communication. We must be careful when considering intentionality and other possible cognitive underpinnings of communication. Potential differences between human and animal communication and the way we approach human vs animal communication.
What is an index?
A signal that cannot be faked
