Exam 2 Flashcards
communication
any aspect of A’s presence or behavior that influences B
Signaler +
Receiver +
Mutualistic
Signaler +
Receiver -
Manipulative
Signaler -
Receiver +
Altruistic
Signaler -
Receiver -
Spiteful
What is a consequence of sending a signal through a channel?
Noise
Signal detection theory:
Signal present
Response
Hit
Signal detection theory:
Signal present
No response
Miss (false negative)
Signal detection theory:
Signal absent
Response
False alarm (false positive)
Signal detection theory:
Signal absent
No response
Correct rejection
What is 1 on this image
Correct rejection
What is 2 on this image
Hit
What is 3 on this image
Miss
What is 4 on this image
False alarm
frequency is the inverse of ______________
period
single sound wave = _____________
pure tone
sign wave
the most basic form of communication signals (every form of communication except chemical)
What is a cost of increasing the amount of information?
More expensive (decreases value)
What is a benefit of increasing the amount of information?
Reduces error (increases value)
H
amount of information transferred (in bits) or amount of uncertainty is reduced
How do you calculate H?
log2n –> n = number of equally probable alternatives
arbitrary signal
signal “removed” from information (most signals) - no general rules, must know what signal means (either innately or through learning)
iconic signal
signal related to, or representing something, about info - general rules establishing information
What is an example of an iconic signal?
honeybee dance
onomatopoeia
graded intensity:
continuous
potentially convey more information
short distance
linear on graph
Typical intensity:
discrete
less subject to misinterpretation
long distance
increases then plateaus on graph
Example of graded intensity
facial expressions
example of typical intensity
signaling flags on ships
Ritualization
complex communication behavior that are originated from other functions
Steps of ritualization
Simplification
Exaggeration
Stereotypy
Repetition of signal
example of exaggeration
male peacock tail
Example of simplification
love birds –> scratching
example of repetition of signal
fiddler crab wave + wild turkey mating dance
When does ritualization occur?
conflict situations
when it reduces the complexity of a signal
Longitudinal wave
particle motion parallel to direction of wave propagation
transverse wave
particle motion perpendicular to direction of wave propagation
Velocity = ___________ x ______________
frequency
wavelength
Sound travels _________ in water vs air because water has a ____________ density than air
faster
higher
Sound velocity of air (at sea level)
340 m/s
Near field
where energy due to particle displacement is greater than (usually < 1 wavelength)
feel it
Example of near field
grouse (booming)
speakers (rock concert)
Far field
where energy due to pressure is greater than (usually > 1 wavelength)
Most animals communication using ___________ field
far
energy is lost more rapidly in __________ field
near
how do you calculate dB?
20 x log10 (P2/P1)
Maximum sound production efficiency occurs when source diameter = ___________
1 wavelength
Why do small animals (insects) struggle to communicate over long distances?
typically cannot produce low frequencies (long wavelengths) with much efficiency
what are solution to small animals struggling to communicate over long distances?
amplify sound by creating an air filled space
prevent acoustic short-circuiting
What two groups have achieved sound production?
Arthropods
vertebrates
What animals have not achieved sound production?
most fish
reptiles
any salamanders
What are the different mechanisms of sound production?
stridulation
tymbal organ
larynx
syrinx
mechanical
what organisms use stridulation sound production?
crickets, katydids, grasshoppers
what organisms use a tymbal organ sound production?
cicadas
what organisms use a larynx for sound production?
mammals (vocal chords after glottis)
frogs (vocal chords before glottis)
what organisms use a syrinx for sound production?
birds
can produce two sounds at once because of two tympanic membranes and two bronchus
what organisms use mechanical for sound production?
woodpeckers
What are different ways attenuation occurs?
spherical spreading
atmospheric absorption
scattering
boundary interference
attenuation
decrease in intensity (loses energy)
degradation
change in signal structure
atmospheric absorption
energy absorbed by air molecules
boundary interference
interference (cancellation) between direct and reflected waves from ground
reverberation
multiple reflections of sound
amplitude fluctuation
due to passage through turbulence
example: talking when windy
what are the two ways sound experiences degradation?
reverberation
amplitude fluctuation
What are closed transmission strategies?
sound window in forests between 1-2.5 kHz (loses energy above or below)
tonal signals - improve S/N for long range (pure tones_
What is an open transmission strategy?
redundant AM signals
What is both an open and closed transmission strategy?
avoidance of background noise
temporal
spectral
What animals use particle-displacement detectors?
lateral line of fish
What animals use open-tube pressure detectors?
insects + frogs
What animals use closed-cavity pressure detectors?
birds + mammals
what two ear types detect near field?
particle-displacement detector
open-tube pressure detector
What does the outer ear do in vertebrates?
collects + channels sound
What does the middle ear do in vertebrates?
amplifies sound
What does the inner ear do in vertebrates?
transduces sound
what does transducing sound mean?
transferring from mechanical to electrochemical energy
What determines frequency in the ear?
what part of the cochlea gets vibrated
incoherent reflection
when waves can be scattered off the object
what can waves do to an object?
pass through
be reflected
scattered
absorbed
refracted
doubling of frequency = ____________
octave
pigments
molecules that differentially absorb and emit wavelengths of visible light
what influences color?
molecular structure
concentration of pigment
tissue in which pigment is found
carotenoids
melanins
carotenoids
come from diet
absorb some of the wavelength (typically blues and purples)
examples of animals that have carotenoids
orioles
house finch
flamingos
Melanins
absorbs all wavelengths
ambient irradiance
spectrum of sunlight, transfer function of air
reflected radiance
spectrum modified by senders surface (transfer function)
background radiance
spectrum modified by background (noise/contrast)
Veiling light radiance
additional noise (reduces contrast)
what can affect ambient light?
medium (air/water)
vegetation
cloud cover
sun angle
why do red fish tend to live near the surface of the water?
red wavelengths are still there and red wavelengths go first the deeper into the water you go
