Ethology is the scientific study of
animal behavior, and a sub-topic of
zoology.
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Proximate vs. Ultimate Causes
• Proximate causes-what mechanism enables
the organism to exhibit the behavior?
• Ultimate causes-in terms of evolution, how
and why did that behavior come to be?
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For example, if a zebra is drinking
at a water hole, and all of a
sudden it hears another zebra
nearby make an alarm call, it may
stop drinking immediately and
start running away instead.
The “proximate cause” is the immediate trigger for a behavior.
• The proximate cause of the zebra running away would be the alarm call.
• But the ultimate cause, or real (evolved) reason why the zebra is running
is survival. It is running away because it wants to survive. The alarm call is
not the source of danger, but the alarm call alerts the zebra that danger,
such as a lion, may be nearby and the lion can threaten the zebra's chance
to survive.
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Another example:
The mouthless jellyfish-Mastigias paupua
migrates upward in the water column during
the day, and descends at night.
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Proximate Explanation– when the sun rises, the jellyfish switch from infrequent, undirected pulsing of their bells to a
clear taxis, directing themselves toward the rising sun and pulsing continuously
• This directed movement brings them to the surface, where they drift into the sunlight.
– Although they lack eyes, jellyfish are sensitive to light and are able to orient themselves
toward it
• This is because electrically coupled, photosensitive neurons control their swimming
behavior and can direct the top of the animal toward the sun.
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Ultimate explanationAlthough they are animals, Mastigias sp. do not eat.
– They are dependent upon photosynthetic algae called zooxanthelle which are imbedded in
their tissues.
Over millions of years, jellyfish that behaved in such a way as to maximize the photosynthesis of
their symbionts left more offspring than others, and ultimately evolved coordinated muscle
contractions to ensure that their symbionts had enough light.
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Innate vs. Learned Behavior
• Innate behavior is developmentally fixed. Despite
differing environments, all individuals that can exhibit
the behavior do exhibit the behavior.
– This does not mean the environment does not play a role,
innate behaviors are triggered by a stimulus which must
occur within the context of the animals environment
• Learned behaviors are modified by experience.
– There is no hard-and-fast distinction between the two,
many learned behaviors have a strongly pre-determined
chronology (I.e., language learning) and many innate
behaviors are improved by experience (I.e., parasitoid
foraging).
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TAXIS vs KINESIS
• A taxis is an innate behavioral response by an
organism to a directional stimulus or gradient of
stimulus intensity.
• A taxis differs from a tropism (“turning response”,
often growth towards or away from a stimulus) in
that the organism has motility and demonstrates
guided movement towards or away from the
stimulus source.
• It is sometimes distinguished from a kinesis, a nondirectional change in activity in response to a
stimulus.
– Example: For example, flagellate protozoans of the
genus Euglena move towards a light source. Here
the directional stimulus is light, and the orientation
movement is towards the light. This reaction or
behavior is a positive one to light and specifically
termed "positive phototaxis”.
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TAXIS vs KINESIS
• Kinesis, like a taxis, is a movement or activity
of a cell or an organism in response to a
stimulus.
• However, unlike taxis, the response to the
stimulus provided (such as gas exposure, light
intensity or ambient temperature) is nondirectional.
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• Example: Pillbugs are decreasingly active as humidity
increases.
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Fixed Action Patterns
• A FAP is a sequence of innate behavioral acts
that is essentially unchangeable and usually
conducted to completion once it is started.
– It is triggered by a sensory environmental stimulus
called a sign stimulus (or releaser).
– Because the animal responds to the sign stimulus,
rather than the environment as a whole, the
animal may be tricked by signals that are out of
their usual context.
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Fixed Action Patterns
Example of a FAP:
• Many mating dances, commonly carried out
by birds, are examples of fixed action patterns.
In these cases, the sign stimulus is typically
the presence of the female.
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Fixed Action Patterns
• Another example of fixed
action patterns is
aggression towards other
males during mating
season in the red-bellied
stickleback.
• A series of experiments
carried out by Niko
Tinbergen showed that
the aggressive behavior of
the males is a FAP
triggered by anything red,
the sign stimulus.
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Fixed Action Patterns
• Another well known case is the classic
experiments by Tinbergen and Konrad
Lorenz on the Graylag Goose.
• Like similar waterfowl, it will roll a displaced
egg near its nest back to the others with its
beak.
• The sight of the displaced egg triggers this
mechanism.
• If the egg is taken away, the animal
continues with the behavior, pulling its head
back as if an imaginary egg is still being
maneuvered by the underside of its beak.
• However, it will also attempt to move other
egg shaped objects, such as a golf ball, door
knob, or even an egg too large to have
possibly been laid by the goose itself.
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All behaviors are influenced by both
genes and the environment
• The extent to which genes control the
manifestation of a behavior differs from one
behavior to the next.
– Example: Alcoholism can actually be broken into
two behaviors; teen-onset alcoholism and adultonset alcoholism.
– Cross-fostering studies using children placed in
foster homes indicate that teen onset alcoholism
has a very strong genetic basis.
– The same studies indicate that adult-onset
alcoholism has a stronger environmental basis.
– All genes, including those whose expression
underlies an innate behavior, require an
environment to be expressed.
– If the same study had been conducted in Saudi
Arabia, there may have been no alcoholics at all
(strong cultural reasons not to drink, and alcohol
less readily available).
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Example of Genetic Variation for a
Behavior-Roving vs. Sitting
• Some behavioral differences are known to
be caused by variation at a single gene.
– In the fruit fly, Drosophila melanogaster, larvae
exhibit two different behaviors.
• “Rovers” crawl around constantly, moving several
centimeters after feeding in a particular location.
• “Sitters” basically stay put.
• The two different behaviors are found in natural
populations, as well as in laboratory strains.
• By isolating rovers and sitters, it was possible to breed
pure strains for the two behaviors.
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Learning
Learning can be defined as a more
or less permanent change in the
behavior or potential behavior of
an animal based upon experience.
• Learning is pervasive in the behavior of birds and mammals,
but other animals are capable of learning as well.
– Example; learning in the sea anemone Stomphia sp.
Chemostimulation, paired with mechanical pressure, will
cause a sea anemone to detach and swim off. With
repeated trials, pressure alone will cause the anemone to
detach itself. YouTube video
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Simple non-associative learning
• Habituation is the relatively persistent waning of a
response to a stimulus when the expected result does not
occur.
– Sensory Adaptation is sometimes called habituation, it is the
phenomenon where environmental noise is filtered out by the
nervous system over time and the animal no longer responds to
it.
• Sensitization is the growing sensitivity of an animal to
repeated stimuli. In essence, it is the opposite of sensory
adaptation-it occurs when the stimulus is rewarded or is of
adaptive significance.
– A search image is an image an animal becomes especially adept
at recognizing, as a result of repeatedly searching for it and
being rewarded for finding it.
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Associative Learning
• These are processes by which an animal
comes to associate events in its environment
with consequences or objects with stimuli.
• Associative learning is the process by which an
association between two stimuli or a behavior
and a stimulus is learned. The two forms of
associative learning are classical and operant
conditioning.
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Classical (Pavlovian) conditioning involves
strengthening of the stimulus-outcome association.
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Classical conditioning (also
Pavlovian conditioning or
respondent conditioning) is a
form of learning in which one
stimulus, the conditioned
stimulus or CS, comes to signal
the occurrence of a second
stimulus, the unconditioned
stimulus or US.
The US is usually a biologically
significant stimulus such as food
or pain that elicits a response
from the start; this is called the
unconditioned response or UR.
The CS usually produces no
particular response at first, but
after conditioning it elicits the
conditioned response or CR.
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Ex: R. Menzel- associative learning in
honeybees
• Bees were trained to enter restraining
tubes.
– Sugar water was offered as a CS
– the orienting response is an extension of
the proboscis by the bee.
• A variety of smells and colors were offered as
US.
• Bees could learn to associate a variety of smells
and colors with sugar water-i.e., they would
eventually extend their proboscis in the
absence of the sugar water
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Operant conditioning is the use of consequences
(reinforcement/punishment ) to modify the occurrence
and form of behavior.
• In Operant conditioning, the behavior emitted by
the organism is strengthened or weakened by its
consequences (e.g. reward or punishment).
– 1. Reinforcing a voluntary behavior. Positive
reinforcement: A child receives a 'gold star' at school
for behaving well.
– 2. Negative reinforcement: A child does his or her
homework to stop her parents from nagging.
Punishment: Grounding a child for behaving
inappropriately
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EX: Operant conditioning
• EX: Skinner Box. An operant conditioning chamber
permits experimenters to study behavior conditioning
(training) by teaching a subject animal to perform
certain actions (like pressing a lever) in response to
specific stimuli, like a light or sound signal.
• When the subject correctly performs the behavior, the
chamber mechanism delivers food or another reward.
• In some cases, the mechanism delivers a punishment
for incorrect or missing responses.
• With this apparatus, experimenters perform studies in
conditioning and training through reward/punishment
mechanisms.
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Skinner Box
(B.F. Skinner)
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QUIZ:
http://www.ar.cc.mn.us/biederman/courses/p1110/conditioning2.htm
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Classical and Operant Conditioning Examples:
1. Every time someone flushes a toilet in the apartment building, the shower becomes very hot and causes the person to jump back. Over time, the
person begins to jump back automatically after hearing the flush, before the water temperature changes.
Answer to Example 1
2. Your father gives you a credit card at the end of your first year in college because you did so well. As a result, your grades continue to get better in
your second year.
Answer to Example 2
3. Your car has a red, flashing light that blinks annoyingly if you start the car without buckling the seat belt. You become less likely to start the car
without buckling the seat belt.
Answer to Example 3
4. You eat a new food and then get sick because of the flu. However, you develop a dislike for the food and feel nauseated whenever you smell it.
Answer to Example 4
5. An individual receives frequent injections of drugs, which are administered in a small examination room at a clinic. The drug itself causes increased
heart rate but after several trips to the clinic, simply being in a small room causes an increased heart rate.
Answer to Example 5
6. A lion in a circus learns to stand up on a chair and jump through a hoop to receive a food treat.
Answer to Example 6
7. A professor has a policy of exempting students from the final exam if they maintain perfect attendance during the quarter. His students’
attendance increases dramatically.
Answer to Example 7
8. You check the coin return slot on a pay telephone and find a quarter. You find yourself checking other telephones over the next few days.
Answer to Example 8
9. Your hands are cold so you put your gloves on. In the future, you are more likely to put gloves on when it’s cold.
Answer to Example 9
10. John Watson conducted an experiment with a boy named Albert in which he paired a white rat with a loud, startling noise. Albert now becomes
startled at the sight of the white rat.
Answer to Example 10
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Imprinting
• Imprinting occurs when an
animal learns to make a
particular response to a
particular object.
– Process is very rapid.
– Can be altered, but the usual
pattern is an instantaneous
and irreversible alteration of
behavior.
• Konrad Lorenz
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Cognition
• The extent to which animals ”think” is unknown,
although it is becoming increasingly obvious that
the human mind differs from those of other
animals largely by the extent of our cognitive
ability, rather than the simple rule humans think,
animals don’t.
– Some hallmarks of cognitive ability
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ability to classify
ability to recognize attributes of objects
ability to count
ability to remember the locations of objects in space
ability to use language
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Some animals for which cognitive
ability has been studied
• Parrots-classification, recognition of
attributes, and language
• Bees, Chimps, Gorillas, Various Monkeys,
Hyenas-Language
• Ants, Bees, Ravens, Various Other Birds-Spatial
Mapping.
• Ex: honeybees “waggle dance” NatGeo video
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PLAY
• Most mammals, some birds, and possibly some other
animals (including elephant-nosed fish) exhibit play
behavior.
– Play is an inexact term that covers a range of behaviors
exhibited by young animals.
– 1) social play-such as wrestling and chasing other animals
– 2) exercise play-such as running, hanging from tree limbs,
etc..
– 3) object oriented play-involves manipulating a novel
object
– The most obvious thing these behaviors have in common is
that they have no immediate adaptive value.
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Functions of Play
• It is frequently hypothesized that
the function of play behaviors is
to practice adult activities in a
context where the consequences
of failure are not serious or fatal.
– Ex: kittens playing with toys,
wrestling with each other
• Establish their relative positions
in the dominance hierarchy
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Other Kinds of Behavior
• kinesis (moves more/less in response to stimulus) and taxis (moves to/away
from stimulus)
• cognitive maps- animal uses cognition to take shortest trip, to plan shortest
route, or to remember location of objects.
• use of landmarks- animal orients behavior patterns to objects in the
environment
• migration- seasonal movement of individuals or whole populations
• dormancy- seasonal or environmentally induced slowdown of metabolism
• antipredator behavior/ predatory behavior
• courtship
• social behaviors
– agonistic behaviors-aggressive interactions
– cooperative foraging
– communication
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References, credits:
• University of Illinois, Chicago
http://www.uic.edu/classes/bios/bios101/zanimalbe
havior/tsld001.htm
• http://www.biology.eku.edu/RITCHISO/behavecolsyl.
htm
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