Transcript Chapter 1
大學部 生態學與保育生物學學程 (必選)
2010 年 秋冬
溝通:管道與功能
(Communication: Channels and Functions)
-- 動物行為學 (Ethology)
鄭先祐(Ayo)
國立 臺南大學 環境與生態學院
生態科學與技術學系 教授
Ayo NUTN Web: http://myweb.nutn.edu.tw/~hycheng/
Part 3. 個體間的互動
生殖行為 (Reproductive Behavior)
親代照顧與交配體系 (Parental Care and Mating
Systems)
溝通:管道與功能 (Communication: Channels and
Functions)
溝通的演化 (The Evolution of Communication)
衝突 (Conflict)
團體生活,利他和合作 (Group Living, Altruism,
and Cooperation)
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15a 溝通:管道和功能
Communication: Channels and Functions
The definition of Communication channels
Vision
Audition
Substrate vibration
Chemical senses
Touch
Electrical fields
Multimodal communication function
Species recognition
Mate attraction
Courtship and mating
Maintaining social bonds
Alarm
Aggregation
Agonistic encounters
Communication about resources: a case study
By Goodenough, McGuire, and Jakob
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Important messages are sometimes whispered
When male Asian corn borer moths are close to a female,
they
Rub specialized scales on their forewings against their
thorax
Produce extremely low intensity ultrasonic courtship songs
Courtship songs suppress escape behavior of the female
and facilitate mating
The quiet song lowers the risks of eavesdropping (偷聽的風
險) by rival males and predators
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Defining communication
Communication occurs when a sender produces a
signal that contains information
And is detected by a receiver who interprets the signal
and decides how to respond
But sometimes an animal is not intended to receive a
message
i.e. an owl hears the noises from a mouse
Cue: provides information to another animal but does
not benefit the sender
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Animals must benefit from a signal
The sender benefits from the transmission by altering
the behavior of the receiver
Signal: a courtship dance, song, feather crest
Display: a stereotyped sequence of behaviors that has a
signaling function
On average, receivers must benefit from paying
attention to a particular signal
But receivers do not always benefit
Sometimes senders manipulate receivers by sending
dishonest signals
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Channels for communication
Feature
Visual
Auditory
Chemical Tactile
Electrical
Effective
distance
Localization
of sender
Go around
obstacles
Speed of
transmission
Complexity
Med
Long
Long
Short
Short
High
Med
Var
High
High
Poor
Good
Good
Poor
Good
Fast
Fast
Slow
Fast
Fast
High
High
Low
Med
Low
Duration
Var
Low
High
Low
Low
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Properties of visual signals
Ease of localization: the location of the sender is known
The receiver can see and, therefore, respond
Rapid transmission and fade-out time
As soon as the sender stops displaying the signal is gone
Visual systems provide a rich variety of signals
Brightness, color, spatial and temporal patterns, movement
and posturing
But, if the sender cannot be seen, its signals are useless
Vision is easily blocked
They are hard to see during nighttime or in dark places
The size of visual signals decreases with distance
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Environmental conditions affect visual stimuli
During agonistic displays, shark species strongly
depress both pectoral fins and hold them down
Sharks in clear water have conspicuous markings on
their pectoral fins
Black or white tips and margins enhance the visibility of
this postural display
Sharks living in habitats where light is scarce only use the
posture
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In many sharks, agonistic displays involve symmetrical depression of the
pectoral fins (胸鰭).
(a) a Galapagos shark using this visual signal of agitation.
(b) Blacktip reef shark have markings on their pectoral fins that may
enhance the agonistic display. Ayo 教材 (動物行為學 2010)
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Use of visual signals in territorial communication
If a roving razorback sucker fish approaches a
territorial male
The territorial male rolls his eyes, exposing the whites
of his eyes
The interloper (闖入者) retreats
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Species use visual signals
At night or in dark places
Nocturnal species that cannot produce light use visual
signals
Are most active at dawn and dusk, when light is available
Colors are difficult to distinguish so visual signals focus
on contrast and involve white
Eagle owls have white feathers on their throat
Visible when the throat is inflated and deflated during vocal
displays
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Although eagle owls are
nocturnal, they use visual
signals at dawn and dusk
when some light is
available.
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The size of visual signals
Conspicuousness of visual signals diminishes with
distance
Animals adjust their visual signals with respect to
receiver distance
Courting male fiddler crabs broadcast their courtship
displays if a receiver (female conspecific) is absent
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As distance decreases, the interval and duration between claw waves decreases
(a) stages in the claw-waving display of male uca perplexa.
(b) the interval between claw waves,
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(c) the duration of claw waves
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(d) the horizontal sweep of the claw tip decrease
with decreasing receiver distance.
Thus, as distance to receiver decreases, male
displays increase in intensity but become less
conspicuous.
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Properties of auditory signals
They can be transmitted over long distances
Especially in water
A rapid means of sending a message
Particularly at close range
Conveys a message when there is limited visibility
Night, deep water, dense vegetation
Sound signals can be complex
Temporal variation of frequency (pitch) and amplitude
(loudness)
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Animals produce a variety of sounds
Sounds are generated by structures that have evolved in
association with respiratory structures
Mammals have a larynx
Birds have a syrinx that produces complex sounds
Sounds are generated by striking objects
Rabbits and deer signal by foot stamping
Beavers slap(拍打) the water
Woodpeckers drum on trees
Sounds are generated by rubbing appendages together
Insects rub parts of their exoskeleton together
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Sound production: stridulation (唧唧鳴聲)
Stridulation: sound production by rubbing body parts
together
Cricket wings have a thickened edge scraper that rubs
against a row of ridges (the file)
Is not confined to insects
A male club-winged manakin creates sound by moving
his wings and highly modified secondary feathers
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A male club-winged manakin creates sound by
moving his wings and highly modified secondary
feathers
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Some animals make sounds that humans
cannot hear
Ultrasounds: sound frequencies are above those
audible to humans
Cetaceans, bats, rodents and other animals produce
and detect ultrasounds as part of echolocation
Male and female concave-eared torrent frog calls have
audible and ultrasonic components
Males approach calling females (positive phonotaxis)
Species can avoid the masking effects of the lowfrequency background noise of streams and waterfalls
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concave-eared torrent frog 凹耳蛙(學名:Amolops
tormotus)為蛙科湍蛙屬的兩棲動物,是中國的特有
物種。分布於浙江安吉縣和建德市以及安徽黃山,一
般棲息于山溪附近。其生存的海拔範圍為380至700米。
該物種的模式產地在安徽黃山。
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Infrasound
Humans cannot hear frequencies below 20 Hz
(infrasound)
Most elephant calls are infrasonic
Infrasonic calls have the same source as audible calls
Air driven from the lungs moves the larynx
Elephants are social animals that live in matrilineal
family groups
Daughters remain with mothers
Sons live in bachelor groups
Long distance communication between family members
and groups is critical
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Infrasound works well for long distance
communication
Low frequency sounds are less degraded
Through refraction (bending of sound waves as they
pass from one medium to another of different density)
Reflection (the bouncing off of a new medium)
Absorption (the conversion of sound energy to heat)
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Substrate vibration
Animals can communicate by seismic signals encoded in
the pattern of vibrations of the environment
The ground or water surface
Produced through percussion on the substrate
Kangaroo rats (更格盧鼠) declare territory ownership
through foot drumming
Blind mole rats bang their heads against the burrow
ceiling
Water striders use vibrational signals for sex
identification, mate attraction, courtship, and territorial
defense
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Kangaroo rats (更格盧鼠)
Blind mole rats
Water striders
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Elephants monitor airborne and ground
signals
Elephants distinguish subtle differences between seismic
calls
To discriminate between alarm calls of familiar and
unfamiliar conspecifics
Elephants detect seismic signals through two pathways
Bone conduction: through the feet, front legs to the
shoulders, and to the middle ear
Mechanoreceptors in the skin of the trunk and feet
Elephants monitor ground-borne and air-borne signals to
determine the distance of the vocalizing individual
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Properties of chemical signals
Smell and taste are another channel for
communication
Based on the movement of odor molecules from
signaler to receiver
Information may be carried by chemicals over long
distances
By currents of air or water
Rates of transmission and fade-out time are slower
than for visual or auditory signals
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Chemical signals are durable (耐久的)
They remain after the signaler has gone
Delineation (描繪) of territorial boundaries
Some mammals increase the signal life of chemicals
Secreting them with oily carrier substances or urinary
proteins
Do not require continued energy expenditure by the
sender
Used where visibility is limited
It is more difficult to locate a signaler using chemicals
than visual or auditory signals
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Signals are complex blends of chemicals
The proportions of different chemicals produce their
effects
Effects are produced by the full chemical “image” of the
signal (the “odor mosaic”)
Scent marking: the act of strategically placing a
chemical mark in the environment
Female marmosets (狨猴) discriminate familiar from
unfamiliar conspecifics
Each female has a unique scent signature (odor mosaic)
based on the ratios of chemicals in the scent mark
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marmosets (狨猴)
Common marmosets deposit
scent marks that are complex
combination of many
chemicals.
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A signal’s meaning varies
With the context in which it is given
As worker bees groom a queen honeybee they pick up a
chemical signal
And distribute it throughout the hive
The chemical prevents the rearing of any additional
queens
The queen also exudes this chemical on her nuptial flight
Causing males to gather around her
This same chemical serves as a queen inhibitor or as a
sex attractant
Depending on the context
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Detection of chemical cues may occur at
a distance
Remote chemoreception: airborne chemical cues
Contact chemoreception: chemical cues are detected
through direct contact with the chemical signal
One ant touches another ant’s body to evaluate
chemicals on the other ant’s body
To determine if the individual is a colony member or an
intruder
Contact chemoreception is associated with nonvolatile
chemical cues
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Some animals have organs for chemical
communication
Amphibians, reptiles, and mammals may have a
vomeronasal (Jacobson’s) organ
For communication between mates, parents and offspring,
and rivals
Its neural wiring does not go to the main olfactory system
It is located in the roof of the mouth or between the nasal
cavity and the mouth
Communicative chemicals reach it through the nose, mouth,
or both
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The flehmen response
Chemicals are nonvolatile and must be brought to the organ
In a snake, the chemicals are delivered by the tongue
A mammal licks or touches its nose to the chemicals and
make a facial grimace(怪相) (flehmen)
To transfer the chemicals to the organ
The flehmen response (from German flehmen, meaning to
curl the upper lip), is a particular type of curling of the
upper lip in ungulates, felids, and many other mammals,
which facilitates the transfer of pheromones and other
scents into the vomeronasal organ, also called the
Jacobson's Organ.
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Flehmen is a characteristic posture in which the
head is raised and upper lip is curled back. It serves
to deliver nonvolatile communicatory chemicals,
such as those found in urine or glandular secretions,
to the vomeronasal organ.
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Pheromones (費洛蒙)
Chemicals produced to convey information to other
members of the same species
Releaser pheromones have an immediate effect on the
recipient’s behavior
A female silk moth emits a minuscule amount of her
powerful sex attractant bombykol
Males immediately turn and fly upwind to find her
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Releaser pheromones
Trail pheromones in insects direct the foraging efforts
of others
Alarm substances in insects warn others of danger
Lactating rabbits produce mammary pheromone
Which stimulates their pups to search for and grasp onto
a nipple
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Primer pheromones
Exert their effect more slowly
By altering the physiology and behavior of the recipient
A queen honeybee produces pheromones that keep her
as the only reproductive individual in the colony
Prevents workers from feeding larvae the special diet
that would cause them to develop into rival queens
When the queen dies the inhibiting substance is no
longer produced and new queens can be reared
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Vertebrates produce primer pheromones
So reproduction occurs in the proper social or physical setting
Origin
Recipient
Effect
Female
urine
Female
Inhibits cycling and ovulation
Male urine
Female
Induces cycling and ovulation
Female
urine
Male
Prompts release of testosterone and
luteinizing hormone
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The vomeronasal organ
There are no functional differences between the
vomeronasal organ
And the main olfactory system
The organ can be stimulated by substances other than
pheromones
A hunting snake responds to chemical cues of prey
brought to the organ by the flicking tongue
Chemicals from prey species are not pheromones
(communication within a species)
The behavior is foraging - not communication
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Pheromones can act via the olfactory system
Scent marks left by a female hamster prompt a male to
locate her
In a sexually inexperienced male, another component of
the vaginal secretion perceived through his
vomeronasal organ prompts him to investigate and
mount her
Sexually experienced males have learned the odor
cues of receptive females
And no longer need the vomeronasal organ to stimulate
mounting
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Properties of tactile signals
Animals communicate by touch
Tactile messages can be sent quickly
It is easy to locate the sender, even in the dark
It is effective over short distances but not around barriers
Honeybee scouts inform nest mates of the location of a
food source by dancing
Recruits follow the dancers’ movements by touching them
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Social grooming, a form of tactile communication
that builds and maintains social bonds, is displayed
by many mammals, including horses.
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A message sent by touch can be varied
By how the recipient is touched,rubbing (摩擦),
patting(輕拍), pinching (擰捏)
Where the recipient is touched
The frequency and duration of touching
The extent of surface area touched
Humans send and decode tactile signals
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Electrical fields
Two distantly related groups of tropical freshwater
fishes produce weak electrical signals used in
orientation and communication
Knifefishes of South America
Elephant-nose fishes of Africa
Torpedo rays and electric eels generate very strong
electric discharges to stun prey or predators
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Electrical signals
Are generated by electric organs
derived from muscle
Muscle cells are arranged in stacks
Their currents are added to result in a
stronger current
When an electric organ in weakly
electric fish discharges
An electrical field is created around the
fish
This field is the basis of the signal
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Creating diverse electrical signals
Different signals can be created by varying
The shape of the electrical field
The discharge frequency
The timing patterns between signals
Stopping the electrical discharge
Electroreceptors in the skin detect electric organ
discharges
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Patterns of electric discharge in weakly
electric fish
Wave-type pattern
Produces signals continuously
Waveform resembles a sine wave
Pulse-type patterns produce electricity at higher rates
when active
And at lower rates when resting
The waveform has a complex multiphasic structure
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(b) Wave type: Some species
of weakly electric fish produce
electrical signals continuously
with monophasic waveforms.
(c) Pulse type: Other species
produce electrical signals in a
pulse pattern, often with
multiphasic waveforms. These
so-called pulse-fish discharge
at high rates when active and
low rates when at rest.
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Sternopygus macrurus
Eigenmannia virescens
Apteronotus albifrons (線翎電鰻)
Sternarchorhamphus macrostomus (胸鉤電鰻)
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Rhamphichthys rostratus
Gymnorhamphichthys
hypostomus
Hypopygus lepturus (下
臀電鰻)
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Properties of electrical signals
When an electric organ discharges
An electrical field is created instantaneously
It disappears the instant the discharge stops
They transmit information that fluctuates quickly
i.e. aggressive tendencies
It does not propagate away from the sender
But exists as an electrical field around the sender
Its waveform is not distorted during transmission
So it is a reliable indicator of the sender’s identity
Waveforms are different between the sexes
And among different species
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Electrical signals suit the environment
For communication in animals
Active at night
That live in muddy tropical rivers and streams
That live at depths where visibility is poor
They can move around obstacles
And are undisturbed by suspended matter
However, they are effective only over short distances
Different weakly electric species may coexist in an
area
So the short effective distance of the signal reduces
electrical “noise” when many individuals signal at once
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Electric signals send the same messages
That other animals send through other channels
Males of some species advertise their sex and species
by electrical signals
They also court females by “singing” an electrical
courtship song
Signals are also used during agonistic encounters
Patterns of discharge are associated with aggression,
dominance, and submission
Parents and offspring may communicate via electrical
signals, to remain close to each other
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Multimodal communication
Multimodal communication: animal displays contain
signals from two or more sensory modalities
Signaling occurs simultaneously or sequentially
The courtship display of a male bird may simultaneously
contain visual and auditory signals
Elephant vocalizations have seismic (ground borne) and
auditory (airborne) components
Messages conveyed in different signaling channels can be
Redundant: convey the same thing or
Nonredundant: convey different things
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Multimodal messages in spider courtship
The courtship display of male brush-legged wolf
spiders contains visual and seismic signals
Visual component: the male raises and lowers his first
pair of legs
Seismic(震動) components: stridulation (唧唧鳴聲) , up
and down bouncing of the body, and striking the substrate
with mouthparts
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Male brush-legged wolf
spider
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Benefits and costs of multimodal
communication
Benefits for nonredundant multimodal signals
More information can be sent per unit time
Insurance that the message is received and recognized
Costs for signaling in multiple sensory modalities
Requires more of the sender’s energy
Recipients need more energy to receive and process multiple
signals
May make senders and receivers more susceptible to
predation
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Functions of communication: species
recognition
Conspecifics are competitors for food, shelter and mates
But potential mates or members of a social group should be
wooed (求婚)
It’s adaptive not to mistake heterospecifics for
conspecifics
Don’t waste time and energy courting an animal with
whom it is impossible to produce viable offspring
Don’t defend a territory from an individual that is not
competing for resources or mates
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All sensory channels are used for species
recognition
Birds use song frequency (which notes are sung) and
syntax (語法) (how the notes are strung together)
Crickets rely on differences in song temporal patterns
Insects use olfactory cues
Some species use species-specific pheromones to
attract mates
Others rely on visual cues, such as displays or color
patterns
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Selection for different species’ signals
Male frogs and toads attract their mates by calling at
night
A female must choose one of her own kind from the
variety of callers at the local pond
Who is the strongest?
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Animals can fail to distinguish conspecifics
Males of many species indiscriminately court females
Australian beetles attempt to copulate with discarded
beer bottles
Even females, the more selective sex, sometimes make
erroneous choices (錯誤的選擇)
In recently introduced invasive species that share
some traits with natives
Natural selection has not had time to favor those
individuals that can successfully make the distinctions
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Signals that attract a mate
Must be species-specific
Easy to locate
Effective over long distances
Chemical and auditory signals are used
Female silkmoth pheromones attract males from 100
meters away
Auditory signals carry well
Amplified by communal displaying or anatomical or
environmental structures
Courtship songs attract mates from long distances
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Female crickets gather on a loudspeaker
that broadcasts the male’s courtship song
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Stop and think
When males signal to attract prospective mates, they
give auditory or visual signals
Females that signal usually use the olfactory channel
Why might this be so?
Think of the duration of receptivity, the costs of signals,
and the dangers of signaling
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Communication: identifies the opposite sex
Individuals court before committing themselves to
mating
Animals communicate their sex
Differences between males and females are apparent
i.e. antlers and other secondary sexual characteristic
Species showcase aspects of their body that indicate
their sex
A female stickleback reduces the probability of attack
by assuming a head-up position
That displays her egg-swollen abdomen
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Identification of the opposite sex
Some gender differences are subtle
Male blue-ring octopuses cannot distinguish males from
females Until late in the courtship sequence
Octopuses mate by inserting their modified third right
arm in to the mantle cavity of the female
And releasing a spermatophore (sperm packet)
Male blue-ring octopuses insert their arm
indiscriminately into both males and females
But only release spermatophores in females
Male-male interactions are brief and not aggressive
Fitness costs of making an insertion into a male are low
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blue-ring octopuses
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Communication: mate assessment
Courtship allows a female to judge the qualities of her
suitor
So she can choose the one most likely to enhance her
own reproductive success
More rarely, it allows the male to choose the
characteristics of an appropriate female
Courtship displays provide a means for evaluating
the suitor’s qualities
His physical prowess (身體能力)
Ability to provide food for the offspring
The extent of his commitment
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Female birds assess male quality
Male common terns (燕鷗) catch fish and offer them to
the female
She compares the quantity of fish provided by her suitors
And chooses the best fisherman
Male wheatears, a small bird, collect stones in their
beaks
And carry them to cavities that serve as potential nest sites
Females watch the males carry stones and even assess
their weight
Male wheatears that carried heavier stones scored better
on a test of immunocompetence (an indicator of male
health)
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common terns 燕鷗
wheatears
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Communication: coordinationof
behavior and physiology
Male and female reproductive systems are not always
synchronized
Courtship displays can function to coordinate the couple’s
behavior and physiology
範例:ring doves
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The mating behavior
of a pair of ring doves.
The sight of the female
causes the male to
increase his
testosterone
production, and he
begins to display.
In response, the female
coos (咕咕叫) , and
her own vocalization
stimulates estrogen
production.
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Many courtship displays are visual or tactile
Displays coordinating receptivity occur at close range
Some displays rely on pheromones delivered at close
range
A male mountain dusky salamander’s courtship
pheromone makes the female more receptive
The female indicates her receptivity and the male
deposits a spermatophore
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During courtship, a
male dusky
salamander injects a
female with his
courtship pheromone.
(a) the male alternately scrapes the female’s back with his teeth and swabs
her with the pheromone, which is produced by a gland beneath his chin. The
female signals her readiness to mate by placing her chin on the base of the
male’s tail and straddling his tail.
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(b) the courtship pheromone makes the female receptive. Tail
straddling and mating occur quickly when a female has been
treated with a courtship pheromone compared to a control
treatment with saline.
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Communication: maintenance of pair bonds
Formation of bonds between
(relatively) monogamous
pairs of animals
Pair-bond displays occur at
close range
Are visual or tactile
Dusky titi monkeys sit with
their tails intertwined
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Pipefish maintain pair bonds year-round
Pipefish are long skinny fish related to seahorses
Pairs are monogamous
Male and female pipefish conduct a greeting ceremony
every morning
Greetings are even carried out during the nonreproductive
season
Functions solely to maintain the bond with the partner for
the next breeding season
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Maintaining social bonds
Social group members use communication to maintain
bonds
Based on contact: resting together, nuzzling, touching
Greeting signals assure nonaggression
Chimpanzees greet each other by touching hands
Sea lions rub noses
Lions rub cheeks
Cats head-bump
Social grooming is different from self-grooming
Skin care is not the most important factor in social grooming
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Maintaining social bonds in primates
In primates, grooming smooths over tension and restores
relationships after conflicts
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Alarm
Alarm signals warn another animal of danger
Predators
Guard against other members of their species bent on
infanticide or other form of aggression
Alarm signals can cause animals to flee or assemble
Flee signals are easy to make quickly but difficult to
locate
Rapid visual signals: flash of a deer’s tail
Volatile pheromones that diffuse quickly
High-pitched sounds
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Alarms cause animals to flee or take cover
Species share similar alarm
signals
Some species even respond to the
signals of other species
Eurasian red squirrels flee or
increase their vigilance when they
hear the alarm calls of Eurasian
jays
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Vervet monkeys use specific alarm calls
When a snake is seen, they emit a low-amplitude alarm call
Capturing the attention of individuals near the caller
Other monkeys respond by looking at the ground
With a leopard, monkeys make loud, low-pitched, abrupt chirps
The call is audible from a great distance
The caller is easy to locate by its fellows
Monkeys scatter and run for cover
With an eagle, monkeys emit loud, low-pitched staccato grunts
Easily located and transmitted over long distances
Other monkeys run into thickets
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Alarm calls that cause animals to assemble
Alarm signals cause those who hear them to congregate
To defend a resource
Or drive off predators
Assembly signals need to easily locate the signaler
Be longer-lasting
And repetitive
Responses can be complex
Ants respond to alarm pheromones by stopping. then
raising their heads, moving toward the source of the
pheromone, and biting the enemy
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Aggregation
Animals aggregate for other reasons besides alarm calls
To hibernate, share a resting place or a roost, prepare for
migration
Bedbugs come out from hiding places and bite sleeping
humans
They release an aggregation pheromone to find each
other
Aggregating bugs have decreased sensitivity to
desiccation
Protection from predators
Ease of finding mates
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Agnostic encounters
Animals conflict with conspecifics over
Food
Territory
Mates
Their places in the dominance hierarchy
Are actions involved in conflict
Aggressive behaviors
Threats and attacks
Submissive behaviors, appeasement or avoidance
Bighorn sheep butting heads, cats hissing, and dogs
rolling on their backs
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The honeybee communication system
Honeybees are central-place foragers
Leaving from a shared nest to collect food
All the labor is done by female worker bees
Older bees forage for flowers, nectar and pollen
Flowers can be widely scattered
Foragers communicate about the new food source to
other bees
Returning foragers do a characteristic dance
Other bees follow dancers
Karl von Frisch studied the dance language for 50 years
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The two dances of honeybees
Round dance: the bee runs in a circle, reverses
direction and circles again
Waggle dance: the shape of a figure 8
During the central run, the bee waggles her abdomen
and buzzes her wings
These dances indicate food sources and distance
information
The round dance does not convey direction
information
Tells recruits to “search for nearby food”
The waggle dance provides distance information
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(a) the round dance, performed after finding food near the hive.
(b) the waggle dance, performed after finding food greater than
about 50m from the hive. During the waggle run through the center
of the figure 8, the bee waggles her abdomen and buzzes her wings.
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The waggle dance provides distance information
After the waggle dance, bees appeared at the scent plate
nearest to the original feeding station
This dance says “food is far away”
And also encodes information about direction and
distance by different aspects of the waggle dance
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The setup of a fan
experiment to determine
whether bees use
directional information.
The solid square shows
the position of the
feeding station during
training, and squares
show the position of the
scent plates, which had
no food.
After following a waggle dance, most recruits arrive at the
scent plate nearest the site of the feeding station. The number of
bees arriving at each station is indicated.
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The setup of an experiment to determine whether bees use
distance information.
The solid square shows the position of the feeding station during
training, and circles show the position of the scent plates.
After following a waggle dance, most recruits arrive at the scent
plate nearest the site of the feeding station.
The number of bees arriving at each station is indicated.
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Dances provide information about direction
The waggle dance helps a bee
determine its departure direction
To know which way to go, bees
need to know the angle formed by
The sun’s azimuth (the point on the
horizon below it), the hive, and the
flower
Dancing bees convey this angle
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Bees use the angle of the run with
respect to gravity
The angle between the waggle run and “up” on the
comb is the same as the angle formed between
The flower, the hive, and the azimuth
If a bee needs to fly toward the sun to reach the flower
The waggle run is oriented straight up
If the bee must fly directly away from the sun
The waggle run is oriented straight down
If the food source is 20° to the right of the sun
The bee does a waggle run 20° to the right of vertical
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Bees adjust the angle of their dances
To account for the earth’s rotation as the sun appears to
move across the sky
Dancing bees adjust the angle of their dances by 15° an
hour
These directions are not precise
Dancing bees repeat their dances
Observing bees take an average of the runs to select a
direction in which to fly
Directions in the dance get bees to the general area of
the resource
From there they use scent to pinpoint the flower’s location
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Dances encode information about distance
Distance to the food source is correlated with two
features of the waggle run
More waggles: the greater the distance to the food
Longer sound trains of buzzes: greater distance to food
The two dances are not as discrete as they first appeared
to be
Round dances contain brief waggle phases that contain
distance information
Round dances contain directional information but are less
precise than waggle dances.
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New technology offers additional insights
Tiny harmonic transponders attached to bees
Return signals to a radar
Researchers can accurately map the paths of
individual bees
Bees that had followed a dance went straight to the
feeder
They did not use odor cues to find the feeder
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Displaced bees
If bees leaving the hive were captured and displaced
They did not fly in the true direction of the feeder
But searched where the dancer had led them to expect the
feeder to be relative to their release point
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Researchers can “talk” to bees
By using a mechanical model of a dancing bee
The model’s dance was not as effective as a live bee’s
dance
Most recruits still showed up at the feeding station indicated
by the dance
Wagging movements and buzzing are two critical
components of the dance
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Bees use optic flow to learn about
distance
Bees rely on visual cues to estimate how far they have
traveled
And convey that information to other bees
Bees trained to fly into tunnels painted with vertical
stripes overestimated the distance they flew
The round dance is given when resources are within 50 m
of the hive
The waggle dances are for longer distances
All the tunnels were well within the 50 m mark
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Bees can be tricked
When bees flew through a tunnel with vertical stripes
They acted as if they had flown a long way
And performed a waggle dance
Even when the tunnel was only 6 m from the hive
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Other cues are also used in foraging
The waggle dance directs bees to a particular area
But not that precisely
The location of the flower is pinpointed by odor cues
Dance followers detect food scents on the dancers
Besides chemical they pick up from food
Dancing foragers also produce other chemicals from their
abdomens
These chemicals cause bees to become primed to look for
food
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Summary
Communication occurs when information is transferred from the
sender to the receiver and the sender benefits, on average
Signal: a behavior that transmits information
Communication channels: visual, auditory, chemical, tactile or
electrical, each with their own
Effective distance, localization of sender, ability to go around
obstacles, speed of transmission, complexity, duration
Pheromones: chemicals that convey information to conspecifics
Vomeronasal organs sense chemical cues
Multimodal communication: animals communicate using
signals from more than one sensory channel
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Summary
Communication is used throughout the reproductive process:
To locate potential mates, signal their identity, advertise their
qualities as a mate, coordinate their physiology, and maintain
pair bonds
Group-living animals maintain social bonds through touch
Alarm signals warn of danger and cause receivers to flee or
assemble
Animals communicate about the location of food resources
Honeybee scouts communicate the direction of food with
A round dance (for nearby resources) or a waggle dance (for
distant resources)
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