Animal Behavior
Chapter 51
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Why study behavior?
 Ethology— the study of behavior
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1941 | 1973
Ethology
pioneers in the study of animal behavior
Karl von Frisch
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Niko Tinbergen
Konrad Lorenz
What is behavior?
 Behavior
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Defined as observable and coordinated responses to
environmental stimuli.
 Result of genetic & environmental factors
Innate Behaviors
 inherited, “instinctive”
 automatic & consistent
 “Built-in”, no “learning curve”
 Despite different environments,
all individuals exhibit the behavior
 Ex. early survival, reproduction, kinesis, taxis
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Evolutionary perspective
 Learned behaviors
 Modified by experience
 Variable, changeable
change with experience &
environment
 Flexible with a complex & changing
environment
 Ability to learn is inherited, but the
behavior develops during
animal’s lifetime
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Levels of Behavioral Analysis
 Proximate causes
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Immediate stimulus & mechanism
Genetic & environmental interaction
Sensory motor mechanisms
“how” & “what” questions
 Ultimate causes
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male songbird
 what triggers singing?
 how does he sing?
 why does he sing?
evolutionary significance
how does behavior
contribute to survival
& reproduction
“why” questions
Courtship behavior in cranes
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 what…how… & why questions
 how does daylength influence breeding?
 why do cranes breed in spring?
Ex. Most people like fatty foods
 What is the proximate cause?
 What is the ultimate cause?
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Answers
 Proximate cause-Because it tastes good
 Ultimate cause- Because it is high in
calories which are the stuff the body needs
to function
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Innate Behaviors-developmentally fixed
Taxis
 Kinesis
 Migration
 FAP
 Animal Signals & Communication

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Innate Behaviors-Taxis
 Automatic response toward or away from a
stimulus.

Automatic movement toward (positive taxis) or
from away (negative taxis) a stimulus
 phototaxis
 Chemotaxis
 Examples:

Trout are and swim upstream so as not to be
swept away.
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Innate Behaviors- Kinesis
 A change in the activity rate in response to a
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
stimulus.
Randomly directed, unlike taxis.
Example:

Sow bugs are more active in dry areas and
less in humid ones; this keeps them in moist
environments.
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Innate behavior: Fixed action patterns (FAP)
Unlearned
 Usually carried to completion once started
 Triggered by a sign stimulus

male sticklebacks exhibit
aggressive territoriality
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Fixed Action Patterns (FAP)
Digger wasp
Human babies
always smile at a
mask with two
dark spots for
eyes.
Do humans exhibit Fixed Action Patterns?
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The “eyebrow-flash”
Fixed Action Patterns Examples

Male stickleback fish will show aggression
toward any shape that has a red area.
attack on red belly stimulus
court on swollen belly stimulus
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Figure 51.3 Classic demonstration of innate behavior
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Complex Innate behaviors
 Migration
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“migratory restlessness” seen in birds bred & raised in
captivity
Migration is learned, but how to learn them is innate
Celestial navigation- by sun, stars, Earth magnetic
fields
Sandpipe
Monarch
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migration
Bobolink
ancient
flyways
Golden plover
Examples of Migration
 Monarch butterflies from our area migrate to
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Mexico in the fall and the next generation flies
north in the spring.
Snow geese fly 2,700 km from James Bay,
Canada to Louisiana nonstop in 60 hours.
The green sea turtle migrates 2,200 km across
the Atlantic ocean from the east coast of South
America to Ascension Island (10 km across)
every 2-3 years where the adult females lay eggs.
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Biological Rhythms & Clocks
 Circadian Rhythms
 “Sleep, wake cycle”
Humans~about 24 hours long
 Drosophila the normal clock is 24.2 hrs
 Mutant flies have cycles of 19 & 28 hrs.
Diurnal —active during the day
Nocturnal —active during hours of darkness
Crepuscular —having greatest activity during
twilight hours or at dawn or both
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Biological Rhythms & Clocks
 Lunar cycles
 Ex.

Grunion swarm from April-June when the
spring tides occur
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Biological Rhythms & Clocks
 What controls the biological clock?
 No single mechanism—an interaction of a
number of biochemical processes
 The pineal gland is thought to play a role
in the timing system of rats, birds and
some other vertebrates.
 In mammals, regions of the hypothalamus
are involved.
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Biological Rhythms & Clocks
 How much is internal and how much is
governed by external clues?
 Answer: There is usually a strong
endogenous (internal) component, but
an exogenous (external) cue is
necessary to keep the behavior
properly timed in the real world.
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Animal Signals & Communication
 An action by a sender that influences the
behavior of a receiver.
 Does not have to be purposeful
 Ex. bat sound pulses influence moth
evasive behavior.
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Communication: Chemical
 Works both day and night
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Social interaction requires communication
 Pheromones
chemical signal that
stimulates a response from
other individuals
Ex. Female moths secrete
chemicals which attract
males.
Cheetahs and other cats mark
their territory with urine,
feces, and anal gland
secretions.
 alarm pheromones
 sex pheromones
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Pheromones
Female mosquito use CO2
concentrations to locate victims
marking territory
Spider using moth sex
pheromones, as allomones,
to lure its prey
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Communication: Auditory
 Faster than chemical and also effective both
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night and day.
Can be modified by loudness, pattern,
duration, and repetition.
Ex. Male crickets have calls and birds may
have one song for courting, another for
distress, and still another for marking
territories.
Humpback whales have complicated songs.
Nonhuman primates have up to 40 different
vocalizations.
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Communication by song
 Bird song
species identification & mating ritual
 mixed learned & innate
 critical learning period

 Insect song
mating ritual & song
 innate, genetically
controlled

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Communication: Tactile
 Occurs when one animal touches
another.
 Ex. A male leopard nuzzles a female’s
neck to calm her and to stimulate her
willingness to mate.
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 Honey bee communication
dance to communicate
location of food source
 waggle dance
 Discovered by Karl von
Frisch in the 1940s.
Waggle dance indicates
both distance to and
direction of food.

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Communication: Visual
 Most often used by species that are active
during the day.
 Contests between males involve threat
postures and possibly prevent fighting.
 Ex. Male birds often put on courtship dances
to attract females.
 Much human communication is nonverbal
such as smiling, blushing, body posture.
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Learned Behavior: Modified behaviors
by experience
Habituation
 Imprinting
 Associative learning

 Classical conditioning
 Operant conditioning
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Cognition
Learning: Habituation
 Loss of response to stimulus
“Cry-wolf” effect
 Decrease in response to
repeated occurrences of
stimulus
 enables animals to disregard
unimportant stimuli
 ex: falling leaves not
triggering fear response in
baby birds

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Innate & Learning: Imprinting
 Learning to form social attachments at a
specific sensitive (critical ) period

both learning & innate components
 Konrad Lorenz- spent time with geese
hours after hatched
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Figure 51.9 Imprinting: Konrad Lorenz with imprinted geese
Imprinting
Konrad Lorenz
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Conservation
Conservation biologists have
taken advantage of imprinting
by young whooping cranes as
a means to teach the
birds a migration
Wattled crane conservation
route. A pilot wearing
teaching cranes to migrate
a crane suit in an
Ultralight plane acts
as a surrogate parent.
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Associative learning

Learning to associate
a stimulus with a consequence
 Operant conditioning
 BF Skinner
 Trial & error learning
 Associate behavior with reward or punishment
 Classical conditioning
 Pavlovian conditioning
 Associate stimuli with reward or punishment
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Operant Conditioning
•Gradual strengthening of stimulusresponse connections.
•Examples:
• Teaching an animal a trick by
rewarding correct behavior with
affection or food.
• B.F. Skinner’s experiments
• Rats connect sugar treat with
pressing a lever.
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Operant conditioning
 Skinner box
B. F. Skinner
mouse learns to associate behavior
(pressing
lever) with reward (food pellet)
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Critical period
 Sensitive phase for
optimal imprinting

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some behavior must be
learned during a receptive
time period
As a brood parasite,
the Cuckoo never
learn the song of their
species as a nestling.
Song development is
totally innate.
Classical conditioning
 Ivan Pavlov’s dogs

connect reflex behavior (salivating at sight of
food) to associated stimulus (ringing bell)
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Learning: Cognition
 Ability for nervous system to store,
perceive, and process information
problem-solving
tool use
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crow
Social Behavior
 Some animals are largely solitary and join
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with a member of the opposite sex only for
mating; others pair, bond and cooperate in the
raising of offspring.
Still others form a society in which members
are organized in a cooperative manner.
Society— a group of individuals of the same
species that cooperate in an adaptive manner;
e.g. bee hive, flock of birds, wolf pack, school
of fish.
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Social behaviors
 Interactions between individuals
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develop as evolutionary adaptations
Result in survival and reproductive success
Agonistic behaviors
Dominance hierarchy
Cooperation
Altruistic behavior
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Social behaviors
 Agonistic behaviors

Threatening & Submissive rituals
 symbolic, usually no harm done

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ex: territoriality, competitor aggression
Social behaviors
 Dominance hierarchy

social ranking within
a group
 Pecking order
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Dominance Hierarchies
 A higher ranking animal has greater
access to resources than a lower ranking
animal.
 Decided by confrontation during which
one animal gives way to another.
 Once established, little or no time is
wasted in fighting.
 Dominant male mate more often with the
females.
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Territoriality-- Protecting an area against
other individuals.
 Male songbirds sing to signify their

territories and other males know to stay
away. The song also alerts females to
presence of a male.
May be adaptive—tends to reduce conflict,
to control population growth, and to ensure
the most efficient use of resources by
spacing organisms throughout a habitat.
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Social behaviors
 Cooperation

working together in coordination
Pack of African dogs
hunting wildebeest
cooperatively
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White pelicans “herding”
school of fish
Social behaviors
 Altruistic behavior
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
Reduces individual fitness but
increases fitness of others in a population
kin selection
 increasing survival of close relatives passes
these genes on to the next generation
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How can this be of adaptive value?
Belding ground squirrel
Examples of Altruistic Behaviors
 In social insects such as bees, only the queen
bee and her mate reproduce.
 A female chimp often mates with several
males in a group because they are all related
and share genes in common.
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Mating & parental behavior
 Genetic influences

changes in behavior at different stages
of mating
 pair bonding
 competitor aggression
 Environmental influences

modifies behavior
 quality of diet
 social interactions
 learning opportunities
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Social Behavior & Reproduction
 Natural selection has favored mechanisms
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that promote successful reproduction.
Behavior is thus adaptive—behavioral
traits can evolve.
Sexual competition among males has
contributed to the evolution of large size,
brilliant breeding colors, antlers, etc.
Known as sexual selection and the traits
are called secondary sexual
characteristics.
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Social Behavior & Reproduction
 Courtship rituals may be long and elaborate.
 May serve as a sign signal to trigger nest

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building and ovulation.
Male spiders offer food.
Female praying mantis eats head of male
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Behavior: Nature or Nurture?
 Behavior is also shaped by
environmental influences (nurture).
 Studies of human twins have been used
to help determine to what extent
behavior is inherited.
 Identical twins come from a single
zygote. Fraternal twins are derived
from two different fertilized eggs.
 Fraternal twins, even when raised
together, do not have similar behaviors.
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 Identical twins raised separately are

sometimes very similar; for example,
the German twins raised in Germany
and the Caribbean both liked sweet
liqueurs, stored rubber bands on their
wrists, read magazines from back to
front, dipped buttered toast in their
coffee, and had similar personalities.
Data seems to show that about 50% in
human personality traits are due to
polygenic inheritance and 50% are due
to environmental influences.
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