Communication and Signals Flashcards
What is umewlt?
The perceptual world
Von Uexküll hypothesis
Animals can occupy different unwelten while sharing the same environment
What modalities can animals sense that humans cannot?
- Magnetoreception
- Electroreception
- Infrared wavelengths
- Ultraviolet and polarized light
What methods do researchers use to conceptualize animals’ sensory experiences?
- Comparative anatomy and physiology
- Consider the ecological context
- Conduct ethological observations
- Conduct experimental studies
- Use models or simulations
Subjectivity/limitations in conceptualizing sensory experiences
- Subjectivity: animals cannot communicate their perceptions directly; researchers rely on indirect measures to infer
- May attribute significance to things that we perceive as complex or striking
What is the difference between signals and cues?
Signals are intentional and evolved for communication, cues are accidental byproducts of other processes.
Signals
- Acts or structures that evolved specifically to influence the behavior of another organism (the receiver)
a) Evolved for communication
b) Example: Birdsong to attract mates
Cues
- Incidental sources of information that animals can exploit, but it wasn’t evolved for communication
a) Not evolved to influence
b) Example: Rustling leaves indicating a predator
Aspects of signals: strategic component
- Strategic component = the message the signal conveys
- E.g. ‘I am strong’, ‘I want to mate’
- Drives what information the receiver is meant to extract
Aspects of signals: efficacy component
- The design of the signal that helps it be noticed and understood
- Involves how the signal is built to transmit clearly
- Includes things like intensity, contrast, detectablity, and learnability
Key features (Guilford & Dawkins):
- Distinguishability from background
- Discriminability from other signals
- Memorability/learnability
Key features of the efficacy component (
- Distinguishability from background
- Discriminability from other signals
- Memorability/learnability
Signal costs: Why would animals evolve costly or risky signals?
Handicap hypothesis (Zahavi)
- Costly elaborate displays could be favored precisely because they are costly, which makes them reliable
- Problem: Cost cancels out the benefit (at first) because offspring bear the cost of costly display
- Solution (Grafen): Signal cost must be higher for low-quality individuals than high quality ones (only the fittest can afford to signal)
- E.g. stalk-eyed flies: only well-fed males could afford to grow wide eye spans
Not all costs are energetic - social penalties can maintain honesty too
- E.g. paper wasps:
- More facial spots = higher dominance
- Faking it (painted on spots) = attacked more by others
- Honesty enforced by aggression toward wasps with more spots (cheats can’t handle)
What are multimodal signals?
- Signals that use two or more sensory modalities (e.g. visual and chemical)
Hypotheses for multimodal signals
- Multiple messages
- Redundancy
- Altering components
Hypothesis for multimodal signals: multiple messages
- Each signal component provides different info → better informed receivers
- E.g. snapping shrimp respond less aggressively when chemical & visual cues are combined
Hypothesis for multimodal signals: redundancy
- Components give the same message → reduces error
- E.g. moths respond similarly to sound or pheromone → works even if one fails
Hypothesis for multimodal signals: altering components
- One part of the signal grabs attention for the important part
- E.g. Yellow-chined anoles do push-ups to get attention before head-bobbing
Ritualization of signals results in ___
Emancipation
Ritualization of signals
- Evolutionary modification of non-communicative traits, and these modifications improve signal function
- E.g. the trait/signal becomes more intense/formalized
- Results in emancipation - behaviors are ‘evolutionarily freed’ from the factors that caused them
Example of ritualization of signals and emancipation
Original (non-communicative) behavior:
- Male birds feed females during mating season (not originally meant as signal, just practical)
- Becomes ritualized → evolved into a formalized courtship behavior - offering food in more specific, exaggerated posture
Emancipation:
- Behavior decoupled from its original function (feeding for survival) and took on a communicative function in courtship
Signaling cost: eavesdropping
- Eavesdropping of signals can be done by potential predators, potential rivals, or parasites
Minimizing eavesdropping can be done in the following ways:
-Change behavior
- E.g. stop calling when predators are present
-Reduce signal detectability
- E.g. reduce the flashiness of a signal- guppies have less bright spots
-Use private/hidden communication channel
- Communicate in red light wavelengths since predators can’t detect
