Dept of Biology, Lewis and Clark College | Dr Kenneth Clifton
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Biology
352 Lecture Outline
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The ethology of communication II: Signal design and honesty vs deceit in communication
Reactors and the design of signals based on signal content rather than signal modality
Consider how signals originate
Most displays appear to have evolved from movements or postures that correlated with future behaviors
Intention movements
Displacement activities
Ritualization: the evolution of signals to improve their effectiveness
Understanding the generation and reception of signals is only part of communication. What about information content?
Consider "why" animals signal to others....
To send truthful information or to send deceitful information
The "intent" of a signal may influence its design.
Hypotheses for the evolution of signal design
Reduction of ambiguity (stereotyped signals clarify the message)e.g., bird calls in the forest vs grasslands
Deceitful messages (manipulation and bluffing by sender)
e.g. contest competiton for resources (sneakers, fake alarm calls, bluffs, "attenuators")What about not passing on information (recruitment calls in Vervet monkeys to a fruit laden tree)?
Honest messages (signalling physical or genetic quality)
e.g., mating signals or displays.... "I'm the best"This leads to the idea of "Handicaps......"What prevents cheating?
Finally, acknowledge that constraints upon the receiver's physiological or neurological make up may also influence signal evolution
Example: Swordtails
The size of signal repertoires (variation in signals) often relates to the different contexts facing a communicator.
What happens when the costs and benefits of receiving specific information vary between sender and receiver?
When are "deceitful messages" adaptive?