Transcript Stare sex

Chapter 4
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http://www.naturesongs.com/CRsounds.html
http://birdnote.org/show/wood-wrenstropical-duet
The release of 1 or more stimuli by 1 individual
that alters the likelihood of reaction by another.
- must get a change in behavior to show
communication
- response may be immediate & obvious or occur
much later
ex) doves - as days lengthen, male begins
singing. His singing acts to stimulate female
hormones. Hormones trigger female nest
building behavior.
1) Discrete Signals =
ex) bright yellow band on male cichlid fish
signifies breeding condition
2) Graded Signals =
ex) aggressive display in rhesus monkeys
low intensity = stare
mouth open
head bobs up and down
hands slap ground
lunges
high intensity = attacks outright
3) Composite Signals =
ex) some wasps - attractants from glands in head +
sexual excitants from abdomen
ex) some ants - trail laying shows trail, second
secretion used for recruitment
ex) zebra –
composite of graded
and discrete signals
a. Subtype of composite signal = meta
communication
ex) play behavior in dog - position and
wagging tail indicate that subsequent
aggressive behavior is play.
ex) smile while saying an insult or chasing
- indicates play
4) Context of signals is important for some
species as signals may change meaning
depending on the context.
ex) male E. Kingbird gives the “kitter” call
a. when establishing a territory used to attract a female
b. if female is present, it is used to
appease female & enable his
approach
ex) hand wave
1) Visual signals:
a. can be turned off and on rapidly
b. complexity of visual signals can be high
c. not effective in murky water, over long distances,
around corners (dense undergrowth), or at night
(unless involves light flashes)
d. produced in different ways:
1. body posture and movement
2. color (physical or chemical)
3. light
ex) octopus, Morpho butterfly wings, male elk
posture and head position
Hamilton – Collared lizards
Ribbon Bird of Paradise
Scarab beetle – M; McIntyre + Gemme
Hangingfly-M
Long-tailed dance fly-F
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2) Acoustic signals:
Great Plains toad - B. Sullivan
a. turned off and on rapidly
b. effective at night
c. effective over long distances
d. sender does not have to be visible
e. can be at frequencies predator doesn’t
hear
e. Acoustic signals are produced in different ways:
1. Production of some other activity
ex. mosquito wing beat freq. of female attracts
males
2. Banging or rubbing body part against substrate
ex) termite alarm
ex) riodinid caterpillars have vibratory papillae. If
stressed or poked, papillae shake and hit the
ground, producing substrate vibrations. DeVries
(Science 1990) showed that the vibrations attract
ants. Additional secretions keep ants around as
guards.
3. Rubbing body parts together = stridulation
ex) crickets, ants, beetles, other arthropods
- molecricket male makes a double barrelled
burrow that magnifies his call up to 600m
4. Vibrating membrane - vocal cords, other throat
modification, air sacs
ex) Hipsignathus monstrous
ex) frogs, toads, birds, primates, whales, bats,
Cicadas
5. Pushing air through spiracles - Hissing
cockroach
6. Rattling body parts - rattle snake
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Sometimes signals can be picked up by
others
◦ We see examples that signals have evolved to avoid
predation by eavesdropping predators
Ex. Tungara frog of Central America
Ex. Great Tit mobbing calls aimed at hawks
Tungara frog song is elaborated
with added chucks only if there
are close competitors.
Added chucks can attract bats.
Only for perched hawks
3) Tactile Signals
a. Can be turned off and on rapidly
b. Can send complex information
c. Only effective over short distances
d. Can be over long time periods
ex) courtship in Cranefly: Female touches
male & initiates courtship
= series of tactile signals help in species and
sex recognition
ex) among primates - begging, reassurance,
affection - role of grooming
ex) sematectonic communication - through
constructed nest - Organpipe wasps
4) Chemical Signals
a. most universal
b. can not be turned off and on - more
long term communication
c. effective long distances
d. effective around corners
e. sender can be hidden
f. Terms associated with chemical signals:
Pheromone: Chemical signal between individuals of
the same species; Both signaler and receiver benefit
ex) female limpets release an aggregation
pheromone. Immature larvae are attracted to her.
Female releases a second pheromone that
transforms young into males who can then
inseminate her. If this second pheromone is not
released, the young turn into females.
Allomone: Chemical signal between individuals of
different species; Signaler benefits
ex) Polistes and nest defense using methyl
palmitate
Kairomone: Signals between different species;
Receiver benefits
ex) predators such as a lion may locate their prey
by detecting their odors
g. Sources of chemical signals:
1. Exocrine glands
ex) black-tailed deer mark using feces, urine, and five
exocrine glands (forehead, tarsal, metatarsal,
preorbital, and interdigital glands)
ex) female wolf spider (Lycosid) secretes a pheromone
into her silken strand. This is left on the ground as
she moves around. Males follow these to find a
female. Since the thread is soluble in water, male
doesn’t risk following an old trail.
** individual, nest, or kin recognition can be possible
through a blend of chemical components produced by
exocrine glands. The specific blend or relative amounts of
multiple components can create a nest or individual
fingerprint.
2. feces and urine (above example) and perspiration
ex) the urine of sexually mature rats will elicit aggression in male
rats, but that of females or castrated males will not.
3. surface chemical - in shell or exoskeleton
ex) Balanus balanoides - barnacle has free living larvae which are
attracted to adult settlements. The substance that attracts them
is a protein from the carapace of the adults (arthropodin).
Interestingly: larvae will react only to surfaces impregnated with
the shell extract, not to the protein in solution. The benefit to all
is a good sized population ensures inbreeding will be avoided.
For animals that don’t move around, recruiting new individuals
to the group is important.
Spotted hyena greeting display between females
How did this system evolve?
1) Sensory Exploitation – May be involved. Preexisting sensory perception and bias.
2) Semanticization - Any evolutionary change
that creates or adds to the communication
function of a sensory signal.
Ex) male lobster responds to female molting
hormone = sex attractant
Ex) male mosquito responds to female wing
beat sound.
A behavior pattern changes to become
more effective as a signal
Display - ritualized behavior used in communication
 some movement is functional in one context, then acquires
a second function
 behavior may become simplified, stereotyped, or
exaggerated
Ex) Lyrebird - flips tail feathers over head and shakes
them while calling
Ex) honey pot ants
Ex) Intention movement – Ex. European Cormorant. Male
performs a conspicuous, but non-functional modification
of the take off leap.
Ex) ritualized predation = intention
movement. Male Grey Herons erect
certain crest and body feathers and
perform modified fishing movement to
attract females. = Points head down as
though striking at an object and snaps
the mandibles with loud clacks.
Ex) nest construction and food exchange
may become ritualized courtship
behavior
Displacement movement - conflict between 2
or more behaviors.
Ex) Male faces an opponent, fight or flee
dilemma - pulls grass, picking up pebbles.
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Displays often done at territorial boundaries
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Hyenas social system
– females are
dominant to males
Males display erect
penis to appease
female aggression
prior to mating
Indicates nonthreatening purpose
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Mutant females
with large
clitoris – would
benefit by being
able to appease
more dominant
females.
◦ Submission or
◦ Social bonding
Signals – based on
communication
that can’t be faked
 Cheaters receive
aggression
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◦ Ex. Polistes females
Amount of black on face indicates dominance.
Subordinates with black paint receive more
aggression than dominants with paint but no
change in markings.
Aggression - complex
behavior that causes the
abridgement of the rights
of another.
Agonistic behavior preferred = any activity
related to fighting
whether aggression,
conciliatory, or retreat.
G. Dimijian; Giraffe-M
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http://www.youtube.com/watch?v=u021Pirrk
Zc&feature=player_detailpage
1) Territorial and spacing - defend core area (most used area
around nest, perch, etc) or home range (area used habitually)
2) Dominance - dominant usually benefits by excluding the
subordinates from desired objects or activities
3) Sexual - forced copulation or association, or intrasexual
competition
4) Parental disciplinary aggression - keep kids near, moving, break
up fighting, etc
5) Weaning aggression in mammals
Theory: at a particular time in life of young animal, its genetic
fitness is raised by continued dependence on mom. Mom’s
fitness is simultaneously lowered because she would benefit
more by having more young - thus the conflict of interest.
6) Predatory and anti-predatory aggression
Some debate - cannibalism is at times associated with territorial
behavior.
Anti-predatory aggression - things like mobbing, fighting back
1) Scramble - first to get it, carries it off, no
direct agonistic behavior
2) Contest - two individuals use displays instead
of combat. Dominant individual wins
3) Combat - physical aggression - relatively rare
Why?? Combat is dangerous to dominant
individual, too
Hostility may be aimed at a related
individual, this will hurt inclusive fitness. Also
causes lost time and energy.
1) Dominance hierarchy = sustained set of aggressivesubmissive relationship among a group of animals.
2) Relationships established by displays and short
combats
 One individual is dominant and wins combats.
 Others are subordinate. Subordinate soon reaches
point that it displays submissive behavior as soon
as it encounters the dominant individual.
3) Dominance communication - stare, elevated body,
sure and steady gait
Subordinate - lowered body, baring a vulnerable
body region (dog - belly; ape - hand), look away,
baby or female calls, some apes will grab a baby.
Linear
A
Triangular
B
C
B
A
C
Coalitions - of 2 or more individuals may
become dominant, where neither could alone
A
but
C+B
B
C
A
Loser
A
B
C
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Winners
A
B
C
0
0
0
4
0
1
# of aggressive bouts and who wins
1
3
0
a. Peck Right - When all aggression goes from dominant
to subordinate
b. Peck Dominance - When most goes from dominant to
subordinate
(terminology developed with chicken studies)
c. Absolute dominance hierarchies = rank order is the
same wherever the group goes and whatever the
circumstances. Individual rank changes only with
further interactions.
d. Relative dominance hierarchies = even highest ranking
individual yields to subordinate under certain
situations.
Ex) domestic cats - subordinate’s sleeping quarters
would be yielded
Ex) Hyena troops - change in dominance depending on
who’s territory the groups are in.
a. Priority access to food, nesting sites, and other
needs
b. Priority access to mating opportunities.
study - DeFries and McClearn - lab mice
 Groups of 3 males and 3 females were put together.
 Males quickly established a dominance hierarchy.
The males all had markers, so that their offspring and
mates could by identified.
 Results: 18 of 22 groups the dominant male sired all
litters
3 groups, a subordinate male sired one litter
1 group, a subordinate male sired two litters
dominant males = 1/3 population sired 92% of
the offspring
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http://www.youtube.com/watch?feature=play
er_detailpage&v=g4vPaCoB7co
a. Subordinates may emigrate - attempt to be
dominant elsewhere
b. By waiting, they build resources and may
become dominant.
c. Dominance hierarchy actually reduces agonistic
behavior. Everyone knows dominant and
subordinate relationships prior to contact once
they are established. No fighting after that.
d. Social group may provide better protection and
resources to subordinate than being on own.
a. Age (size and experience in fighting)
b. Sex (some species joint hierarchy, some
males dom., others female dom.)
c. Family rank (that of mother)
d. Cooperative coalitions
e. Health and Strength
f. Home turf - circumstances
g. Luck