Chapter 12
Communication
Ezekiel Gading
TAs: Nicky Sztohrynec & Zacchary Nabaee-Tabriz
Housekeeping
Deadline for Assignment 1 is 7th March (11:59
pm)
Assignments (1 &2) that are submitted on that
day get a 5% bonus for that component.
AI is NOT ALLOWED.
Last day to submit any of the assignments
2 April 2025 (11:59 pm).
Defining
Communication
Communication Defined
Surprisingly difficult to define
Think signals, information, sender, receiver
Signals– evolved body part or behaviour of the
sender that changes the behaviour of the
receiver. (Maynard-Smith & Harper)
Communication Defined
Classic Definition (Cooperative)
Transfer of information between a sender and
receiver. Sender → *signal* → Receiver
Both gain fitness benefits
What kind of relationship between animals allow
this?
Communication Defined
... but relationships between sender and receiver are not always
like this (e.g., prey-predator etc. ).
Manipulator/Mind-reader Definition (Krebs &
Dawkins)
Selection would favour senders (manipulator) to
maximise their own fitness at the expense of the
receiver using signals.
Selection would also favour receivers to detect
manipulation (“mind-reader”)
Manipulator/Mind-reader Definition
Evolutionary arms race
between manipulator and
mind-reader
Better manipulators- Better “mind readers”
Communication Defined
Both cooperative and manipulative
communication exist
Classical-not exaggerated (conspirational whispers)
Manipulative– Exaggerated (think of car salesman)
Deceit Vs Lying
Important to note the intent!
Deceit
No intent
vs Lying
Implies intent
Animals do this Implies “theory of
Typically mind”
cross species Only beneficial if
(anti-predator) everyone else is
honest
Deceit Examples
1)Cross species- killdeer, goats, etc.,
2) Within species
Lordosis in primates
In great apes lordosis does
not always correspond
with fertility
Mechanisms
How do Signals Convey Information
Animals can...
Control signals in different ways:
Discrete (on/off)
Lightningbugs/fireflies
SE Asian Flying Lizards
Continuous/ Graded
vary in intensity
whisper vs talking vs shouting
How do Signals Convey Information
Signals have to travel through the environment.
What’s the best channel to communicate signals?
Visual
Auditory
Chemical
Tactile
Olfactory
Electrical
Vibrations
How do Signals Convey Information
Complexity of signals can vary
Composite signals– different signals can
be combined
Tigers-posture, ears, and vocalisations
Context-dependent signal
same signal different meanings
Metacommunication
communication about context of
behaviours that follow
play bow in dogs
Modality (Channels)
1) Odours/Olfactory
Almost all animals except birds
Pros: long lasting, low cost, works at night, long
range.
Cons: Slow transmission rate, difficulty to identify
sender
Olfactory Examples
Pheromones: chemicals secreted that trigger social
response in members of the same species.
Signalling pheromones- information about the sender
Orienting pheromones-attract and orient (scent trail)
Receivers usually respond with Flehmen response
E.g., Tigers
Modality (Channels)
2) Sound/Auditory
Used by almost all animals
Pros: long range, variety, works at night, can
identify sender.
Cons: Fade quickly
Vary in loudness and frequency
Ultra High frequency (bats,rats, dolphins)
low frequency (kangaroo rats, elephants)
Modality (Channels)
3) Tactile (Touch)
Pros: works at night, can identify sender, low cost.
Cons: short range, fades quickly
Examples:
Modality (Channels)
4) Visual- used by most animals
Pro: Medium range, lots of variety, does not often
work at night (except bioluminescent spp!),
transmits quickly, can identify sender
Cons: Fades quickly, medium cost
Visual Display
Visual communication includes a ‘visual display’!
Communication behaviours (e.g., visual displays)
probably evolved from non-communicative
behaviours, like intention movements/ incipient
behaviour (indication about subsequent action) or
displacement activities (occur in conflict
situations).
Function
Function
Ultimately increase fitness.
In many different ways.
Coordination of Feeding
Space use in wolves
Communicate about food location
Crows and Ravens (Yelling)- Marzluff et al.
Reproduction/ Mate Selection
Basically the chapter on sexual selection
Bird songs are the best example
Mechanism: Birds have a syrinx
e.g., lyre bird of Australia
Aggressiveness/ Social Status
Saves animals from having to fight all the time if they
have a signal about the identity and quality of a
conspecific
Predator Detection
Alarm calls as anti-predator behaviours (e.g., meerkats)
Warns conspecifics of predator presence
Vervet Monkeys
Parent-Offspring Communication
Begging, food sharing, hatching synchronisation
What About Language?
Language is a form of
communication but not all
communication is language
COMMUNICATION
LANGUAGE
Criteria for Language
Arbitrariness of units
Discrete units (e.g., words)
A single object can be referred to by many
different words/languages
Semanticity
Specific meaning
With a limited vocabulary
Criteria for Language
Displacement
Communicating about events in another time
or space
Productivity
Grammar/syntax – rules of production
Create many sentences with a limited
vocabulary
What’s The Point?
They seem like moving goal posts
Anthropocentric-Based on human characteristics
