Communication and Signals I Flashcards
What are three examples of communication between individuals?
(Choose any three)
Males display to females
males display to other males
parents signal to offspring and vice versa
eusocial insects signal about food and threats
pred to prey (both direct and to try to tell prey they aren’t a danger)
What is communication? What are the 3 types of response times and an example of each? (Hint: examples are short) Is no response still communication? Why?
- The use of a signal that has evolved specifically to modify behavior of the receiver
2a. Immediate (male firefly flies to flashing female)
2b. Delayed (ovary development in female budgerigars as a result of male’s song)
2c. Not occur (no response from male intruder or by female to a male blackbird’s singing)
- Yes, life is stochastic
What used to be the general framework in regards to communication? How did this change over time? Which is generally correct?
- Initially: signal gives information to receiver about a state of relevance
- Later: Thought to be manipulative, that sender was being selfish (Dawkins)
- information view because receivers would select for ignoring signals if they were always manipulative but this did not happen
What is a the difference between a signal and a cue? How are each used in the funnel web spider example?
Signal: must, on average, benefit receiver and sender for a stable communicative system
Cue: have not evolved to convey information as a goal, but still give information
Funnel web cue: vibration of web when an insect lands on it by accident
Funnel web signal: Intruder funnel web spiders purposefully vibrate web to send signals about its size (bigger = resident more likely to just leave because fighting = bad)
What are three factors that contribute to keeping signals honest (instead of just lying all the time)?
- Index signals
- Handicap signals
- Common interest signals
What is an index signal? What is a general example? What are two specific examples in animals?
- Signal that CANNOT be falsified
- Frequency of a vocalization is constrained by size of vocal chords/trachea (meadowlarks and northern green frogs) (Small = only high frequencies)
3a. Common toads - bigger males = deeper calls = tell other males off when they try to amplex with their female (tested by silencing amplexed frogs and using rubber bands to make higher or lower calls)
Note: the cue in this example is body size, which conveys information to the intruder without being given by the sender
3b. Red deer stags - three steps to fight. 1) roar (best roar = no fight) (stretch trachea, lower = more successful), 2) parallel walk (bigger = no fight), 3) Fight (but want to avoid this as gouged eyes and stuff)
What is a handicap signal? What is an off-the-top example? How are handicap signals shown to exist graphically? What are two examples (one is high cost, other is relatively cheap)? In the high cost, when happened when food was restricted? In the low-cost example, what was found about manipulation’s effect on both the painted individual and the receiver?
- A handicap signal is one that is high cost, so only high quality individuals can exhibit the signal
- Examples: birds of paradise
- Graph has two axis: cost or benefit vs male quality
There are two important lines, one is benefit (straight line across because benefit is independent of quality) and the other is cost (which increases as male quality lessens (negative slope on the graph)).
4a. Stalk-eyed flies - literal stalks for eyes (increased length between male-female and between male-male).
4b. Polistes paper wasps dominance hierarchy and black markings on face (more broken up = more dominant)
- Stalk length decreased drastically compared to other body parts (such as wings).
- When faces were painted on to the wasps, the new markings had no effect on who won (wasps can’t see their own faces). BUT wasps painted dominant that LOST had 6x more mounting on their heads.
What is an important bottom line about handicap signals demonstrated by the paper wasp example?
The cost doesn’t only have to be energy, but also social. (Liars get more punishment than non-liars)
What are the two types of signal cost and what do they mean? What kind of signals have what kind of cost? What is one last example of a handicap that demonstrates this?
- Efficacy cost (signalers need resources to produce the signal) (All three)
- Strategic cost (cheaper for high quality signalers) (Handicap extra cost only)
- Peacock and huge tails (more likely to be prey, less immune functions)
