Transcript Animal Behavior

Animal
Behavior
What is behavioral ecology?
 Behavioral
ecology studies how behavior
is controlled and how it develops, evolves,
and contributes to survival
 Behavior is everything an animal does
and how it does it
 Ethology is the scientific study of how
animals behave, especially in natural
environments
Understanding Behavior
 Questions
that must be asked to understand
any behavior:
 What is the mechanistic basis of the
behavior (chemical, anatomical, and
physiological mechanisms)?
 How does development of the animal, from
zygote to mature individual, influence
behavior?
 What is the evolutionary history of the
behavior?
 How does the behavior contribute to survival
and reproduction (fitness)?
Fixed Action Patterns
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One type of behavior studied by ethologists is the fixed
action pattern (FAP)
An FAP is a sequence of unlearned behavioral acts that is
essentially unchangeable and, once started, is usually
carried to completion
 Triggered by a sign stimulus (some external sensory stimuli
that triggers the behavior
Example: Aggressive behavior in male stickleback fish in
response to the red underside of an intruder fish
The following models were
used to induce aggressive
behavior. The realistic model
did nothing, but the shapes
with red bottoms caused
aggressive behavior
Imprinting
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Imprinting is a type of behavior
that includes both learning and
innate components and is
irreversible
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There is a limited phase in an
animal’s development which
is the only time when certain
behaviors can be learned
(sensitive period)
Incubator-hatched goslings
imprinted on scientist (Konrad
Lorenz) during first few hours of
life and followed him
Nature vs. Nurture?
 In
biology, it’s not an either/or scenario
 Genes and the environment both influence
behavior
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Some behaviors can be altered based on the
environment (still set behavior, but the behavior
changes based on changing external conditions)
Other behaviors are virtually identical in a
population . . . regardless of external stimuli
 Innate
behavior is behavior that is
developmentally fixed, regardless of the
environment
Directed Movements
 Animal
movements can have
substantial genetic influence
(directed movements)
 Examples:
Kinesis
Taxis
Migration
Directed Movements
 Kinesis:
a simple change in activity
or turning rate in response to a
stimulus
Example: pillbugs live best in moist
conditions; they move around
more in dry areas and less in
moist/humid areas
More movement increases
likelihood they will encounter a
moist area
Directed Movements
 Taxis
= a more or less automatic,
oriented movement toward or
away from a stimulus
Example: fish swimming against
the current
 Migration
Animal Signals & Communication
 Many
interactions between organisms
are a result of sending and receiving
information that alters behavior
 A signal is a behavior that causes a
change in another animal’s behavior
 Communication involves the
transmission of, reception of, and
response to signals between animals
Types of Communication
 Chemical
Communication:
 Pheromones – chemically emitted odors
that may attract organisms from several
kilometers away. Particularly important
in reproduction behavior
 Auditory Communication:
 Bird songs and insect songs are also
important in reproduction
 Drosophila males produce a
characteristic “song” by beating their
wings
Environment & Genetics

Environmental factors, such
as the quality of the diet,
the nature of social
interactions, and
opportunities for learning
can influence the
development of behaviors
in every group of animals

Example: Variations in diet
led to rejection of mates in
Drosophila
Learning (start here)

Learning is the modification of behavior based on
specific experiences
 Learning has a large range of expression
 From simple imprinting to “learn” to recognize a
parent to extremely complex . . . i.e. AP Biology
 Habituation: loss of responsiveness to stimuli that
convey little or no information
 If you poke a hydra, it will contract into itself. Yet,
if you keep poking the hydra (not very nice),
eventually it will ignore the stimuli if it is not
harmed
 Evolutionarily it is believed this prevents organisms
from wasting energy on stimuli that are not
pertinent to survival or reproduction
Learning
 Spatial
Learning: the modification of behavior
based on experience with the spatial structure of
the environment, including the location of nest
sites, hazards, food, and prospective mates
 Example: Organisms being able to recognize
landmarks
 This is a much more sophisticated form of
learning because it involves “learning” stimulus
that may vary in an environment
Learning
 By
putting together several landmarks in a
spatial learning scheme, organisms could
traverse to a variety of different environmental
locations
 Another possibility is the use of cognitive maps,
an internal representation of the surrounding
environment with spatial relations to each other
(a mental map)
 Sometimes it is difficult to determine if an
organism is using spatial learning or relying on
a cognitive map
Associative Learning
 Another
type of learning has to do with an
organism learning behaviors based on
experiential factors
 Associative learning is the ability of many
animals to associate one feature of the
environment with another
 Example: Associating eating one type of
insect with a bad taste
Types of Associative Learning
 Classical
Conditioning
 an arbitrary stimulus is associated with a
reward or punishment
 Example: Pavlov’s Experiment
 Operant Conditioning
 “trial-and-error learning”
 Example: Mouse eating distasteful
caterpillar OR a coyote getting a
face full of quills from a porcupine
Cognition & Problem Solving
 Some
behaviors show more sophisticated levels of
learning
 Cognition is the ability of an animal’s nervous
system to perceive, store, process, and use
information gathered by sensory receptors
 Cognitive ethology studies how an animal’s
nervous system and behavior interact
 Example: chimpanzees cracking open oil
palm nuts by observing an experienced
chimpanzee performing the task
Natural Selection & Behaviorism
 The
genetic components of behavior evolve
through natural selection
 Natural selection favors behaviors that increase
survival and reproductive success
 Foraging behavior – Balance between benefits of
nutrition and cost of finding food (predation,
energy, etc.)
 Cost-benefit analysis
 Mating systems and parental care
 Most animals are promiscuous (no strong pairbonding relationship)
 Monogamous
 Polygamous (usually single male with many
females)
Reasons for mating systems
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Finding mates, caring for young, and passing on
genetic traits are strong determining factors in mate
selection
Monogamy is important in birds. It takes a lot of
work to feed and care for young that are relatively
helpless. Both male and female are needed to
provide for young, so they stick together
Polygamy occurs when the young can care for
themselves at a young age. Males seek to
maximize reproductive success
There are many other factors that influence
behavior
Sexual selection
 Reminder:
 Intersexual
selection: one sex chooses a
mate based on some characteristic of
the other sex (female usually makes the
selection and males vie for selection)
 Intrasexual selection: competition of
one sex for mates (males fight each
other to “win” a female)
Evolutionary impact
A
lot of male behaviors, or anatomical features,
may be due to intersexual selection
 Females choose traits and those traits become
selected for
 Peacock feathers, birdsong, long eyestalks in
male stalk-eyed flies
 Male behaviors, or anatomical features, may also
be due to intrasexual selection
 Agonisitic behaviors are ritualized competitions
that teach males to fight for mates
Altruism & Inclusive Fitness
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Most social behaviors are
selfish
Altruism = when an animal
behaves in a way that
reduces its individual fitness
but increases the fitness of the
other individuals in the
population
 Example: squirrels alarm
call, worker bees
Helps close relatives (children,
siblings, etc.), thereby
increasing the individual’s
genetic representation in the
next generation (saving close
relatives) – “inclusive fitness”
Reciprocal Altruism
 Sometimes
animals will behave
altruistically to other animals that are not
related
 This behavior can be adaptive if it aids
the animal in the future, reciprocal
altruism
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Reciprocal altruism is rare in animals
Limited largely to same species that live in a
social group, but not always related
(chimpanzees)
Social Learning
 In
addition to genetic and environmental
influences, learning can be influenced by
social contact
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Social learning is learning from observing
the behaviors of others
Social learning forms the roots of culture
Mistakenly, we believe social learning only
occurs in humans. It may also occur in
animal populations
Social Learning
 Example:
Mate choice copying
 Female guppies have been seen to mate with
males that have been successful in attracting
other females
 Example: Alarm calls
 Monkeys learn different calls to symbolize
different predators (leopards, eagles, snakes)
 When young these calls are inaccurate (any
bird may be given the “eagle” call
 Yet, as they mature and “learn” to discriminate
species, their calls become more accurate
What about us?
 Biology
is not limited to the study of just
animal behaviors
 Some scientists study how evolutionary
theory applies to human culture,
sociobiology
 This field is highly controversial
 Could be used to justify status quo
human societies (caste systems)
 Risk of oversimplification