Animal Communication Flashcards
When does an animal actually communicate with another animal?
When A’s behavior manipulates B’s sense organs in such a way that B’s behavior changes
Primary functions of animal communication
- Regulating social interaction (often by expressive attitudes toward social partners)
- Giving information (e.g. location of food sources, predators, nest sites)
Ways to assign meaning to an animal signal
- Look at the state of the signal animal (encoding)
- Observe the response of the receiving individuals (decoding)
- e.g. bees communicating with their movements
Ritualization
- The evolutionary process by which a behavior pattern becomes increasingly effective as a signal
- Begins with a behavior that is functional in another context
- The behavior eventually acquires a secondary value as a signal (e.g. human disgust facial expression)
Interspecies communication
- Symbiotic relationship between cleaner fish and larger fish like sharks
- Dog-human communication: dog owners and non owners could tell the difference between aggressive, fearful, and playful barks
Crows decoding static and artificial sign vehicles
- Birds trapped by “dangerous” face mask and normal faces
- Birds didn’t scold the dangerous mask prior to trapping
- After trapping, crows scolded the dangerous face mask only
- After normal faces trapped birds, they did not get scolded
- Memory effect held 2.7 years after trapping
Olfactory communication
- Earliest form of communication (chemical)
- Rich in information: age, physical fitness, reproductive status, etc.
- All but lost in primates, esp. humans
- Can travel great distances
- Some receivers are highly sensitive (e.g. female silk moth and bomobykol - able to detect ONE molecule!!)
- Influence receivers’ actions
- Scent can function as (1) territory marker, (2) a personal perfume
Auditory Communication
- Sound signals can vary in pitch, loudness, frequency, and temporal pattern
- Some only vary one of these (e.g. crickets)
- Most vertebrates modulate temporal patterning and frequency
- Sounds of the humpback whale can travel around the world in sound tunnels (underwater grand canyons)
- Sound producing capacities can be artificially expanded (megaphone style)
Predator alarms in marmosets
- Showed marmosets 1 of 4 different models of a predator (owl, falcon, 2 snakes)
- Recorded their alarm calls
- Played back their alarm calls to other marmosets
- Recorded gaze of decoder
- Calls given to birds are acoustically distinct from those given to snakes
- Marmosets looked up while listening to playbacks of bird-elicited calls and down for snake-elicited calls.
Visual Displays
Displays are stereotyped motor pattern (they were once instrumentally functional, but now have a symbolic function)
Origins of displays
1) High emotion
2) intention movements (ex: warning/attacking: intentional)
3) displacement movements (ex: caged animal pacing)
Postures
- Display posture often show off distinctive features (e.g. color patterns, weapons)
- Can be a deterrent without injury to the adversary
- Evolved as signals
- Can be deceptive (e.g. distraction displays - making animal pay attention to you so that the predator doesn’t pay attention to something else, like their young)
Adjusting communication posture and movement to avoid predation
BROWN ANOLE LIZARD
- 3 visual signals, (1) pushups (2) head bobs (3) the dewlap expression (a throat fan)
- Head bob is least conspicuous
- Stimulated attack with model of kestrel on fishing line
- Lizards kept emitting head bobs but reduced dewlap expression and pushups
Animal facial expressions
- Humans are very advance users of facial expression
- Facial expression mostly used just my mammals
- The more evolved the animal is, the more sophisticated its facial repertoire is (also have good vision)
- Many similarities between human and nonhuman primate expression
Space and territoriality
- Perfect balance of costs (energy to defend) with benefits (food, mates)
- Some only defend territory during the breeding season
- Spacing out from neighbors decreases the effect of predation and disease
- Usually territory is only defended against members of same species who will consume same resources (rabbits don’t attack birds for territory because they don’t use the same resources)