Download Behavioral Ecology

Behavioral Ecology
Monkemeier
AP Biology 2011
Why Behavioral Ecology?
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Ecology is the study of the interactions
between organisms and their environment
A key theme in ecology is
INTERDEPENDENCE
Behavioral Ecology: studies how behavior is
controlled and how it develops, evolves and
contributes to survival and reproductive
success.
Behavior
 Everything
an animal does and
how it does it, including muscular
activities such as chasing prey,
certain non-muscular processes
such as secreting a hormone that
attracts a mate, and learning.
Proximate and Ultimate
Causes of behavior
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PROXIMATE
Focus on the
environmental stimuli
that trigger a particular
behavioral act, as well
as the genetic,
physiological, and
anatomical
mechanisms underlying
it.
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ULTIMATE
Focus on the
evolutionary
significance of a
behavioral act.
Behavior’s Two Components
 Proximate
How it all works – how
does the animal’s
senses, nerve
networks, or internal
state provide a
physiological basis for
the behavior.
The HOW of a behavior is
a question about
proximate causation.
 Ultimate
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WHY a behavior
evolved – an
investigation of its
adaptive value.
The WHY of a behavior
is a question
concerning ultimate
causation.
Proximate Questions vs. Ultimate
Questions
PROXIMATE
Proximate questions are often
referred to as HOW
questions.

Examples: Why does a male
stickleback fish attack
another male predator?
ULTIMATE
Ultimate questions answer why
did natural selection favor
this behavior and not a
different one?
Example: Does attacking
behavior in male stickleback
fish benefit his offspring or
his breeding choices?
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How do we ANALYZE and MEASURE?
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What causes male
songbirds to sing during
breeding season?
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To analyze the proximate
cause of the behavior, we
might measure hormone
levels or record the impulse
activity of neurons in the
animal.
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Why did singing during
breeding season evolve –
how does it influence the
animal’s survival and
reproductive success?
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Investigate how the song
itself, or timing of song, etc.
relates to the number of
mate choices, size of
breeding territory, number of
offspring produced, etc.
Behavioral Ecology - Ethology
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The scientific study of how animals behave,
particularly in their natural environment.
Early research in ethology focused on
behavioral patterns that are always exihibited
by members of a species in response to a
particular stimulus; that is, they appeared to
be instinctive, or innate behaviors.
Innate Behavior Does NOT require
LEARNING
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Fixed action pattern (FAP) a sequence of
unlearned behavioral acts that is essentially
unchangeable and, once initiated, is usually
carried to completion.
Sign stimulus: a sensory stimulus that
triggers or initiates a FAP
Innate Behavior
Innate Behaviors – Strong Genetic
Component
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Innate behaviors are under strong, genetic
influence.
Directed Movements: (types of innate
behaviors) Movements that are strongly
controlled by genes.
Directed Movements
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Orientation: a process that involves tracking
stimuli in the environment.
Kinesis: simple change in activity or turning
rate in response to a stimulus. Some animals
just become more or less active when
stimulus intensity increases.
Taxis: movement toward or away from a
stimulus
Orientation and Migratory Behavior
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Orientation: the ability to follow a bearing, analogous
to a using a compass.
Navigation: the ability to set up or adjust a bearing,
and follow it, analogous to using a compass and a
map.
Migrations are long – range, two – way movements
of animals using orientation or navigation (or both).
Inexperienced animals migrate by orientation, and
experienced animals navigate by navigation.
Learning
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Many behavioral patterns displayed by
animals are not solely the result of instinct.
Learning: the modification of behavior based
on specific experiences.
Learning
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Habituation: the loss of responsiveness to
stimuli that covey little or no information.
Spatial learning: the modification of behavior
based on experience with the spatial
structure of the environment, including the
locations of nest sites, hazards, food and
prospective mates. (landmark = location
indicator)
Associative Learning
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Associative Learning is the change in
behavior that involves an association
between two stimuli or between a stimulus
and a response. The ability of many animals
to associate one feature of the environment
(a stimulus, such as color) with another (bad
taste).
Associative Learning
Classical Conditioning
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An arbitrary stimulus is
associated with a
reward or punishment
Operant Conditioning
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An animal learns to
associate its behavioral
response with a reward
or punishment. Aka trial
and error learning.
The Development of Behavior
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Behavior has both genetic (nature) and learned
components. (Environment - nurture has an effect)
Imprinting: a form of learning in which a young
animal forms a social attachment to other individuals
or develops preferences that will influence behavior
later in life.
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Sensitive period: time in the organism’s life when imprinting
is effective.
Animals may have an innate genetic template that
guides their learning as behavior develops.
Animal Communication
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Communication between and among species
is the key to many behaviors.
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Successful reproduction depends on the
progressive exchange of appropriate signals and
responses.
Courtship signals are usually species-specific and
limit communication to members of the same
species.
Communication includes visual displays, sounds,
electrical signals and pheromones.
Behavioral Ecology: the study of how natural
selection influences behavior that increases
survival and reproduction.
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Natural selection favors optimal foraging strategies
in which energy acquisition (cost) is minimized and
reproductive success (benefit) is maximized.
Some animals are territorial. Territorial defense has
its costs, and territoriality my only occur when the
benefits outweigh the costs.
Game Theory – the fitness of a particular behavioral
phenotype is influenced by other behavioral
phenotypes in the population.
HOW do we KNOW that behavioral
traits can evolve by natural selection?
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Studies have found that behavioral variation
within a species corresponds to variation in
environmental conditions.
Laboratory studies of Drosophila populations
raised in high- and low- density conditions
show a clear divergence in behavior linked to
specific genes.
Studies of migratory behavior in European
blackcaps over a period of a few decades.
Reproductive Strategies and Sexual
Selection
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Reproductive strategy is a set of behaviors
that maximize reproductive success.
Reproductive strategies are responses to the
spatial distribution of food resources, nest
sites, and members of the opposite sex.
Reproductive strategies include
–
Mate choice, number of mates chosen, parental
investment in care of offspring.
Examples – Mate Choice
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The direct benefits of choosing the right mate
offers advantages of territory quality, degree
of parental care and an indirect benefit is the
quality of genes.
Intrasexual selection involves members of
the same sex for the chance to mate.
Intersexual selection refers to a choice of
mate by members of the opposite sex.
Examples – Mating Systems
Monogomy
 Polygyny
 Polyandry
ALL of the above are influenced by ecology
and constrained by the needs of the
offspring.
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Altruism and Group Living
Altruism refers to the action of an individual that
benefits the fitness of another individual or
individuals.
- Sometimes animals behave in altruistic ways
that reduce their individual fitness but
increase the fitness of the recipient of the
behavior -WHY
Altruism and Group Living
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Seemingly altruistic acts may not be altruistic
because the helpers benefit by learning valuable
experiences, inheriting territories, or increasing the
ability to escape from a predator.
Kin selection increases the reproductive success of
relatives and frequency of alleles shared by kin.
Hamilton’s rule is a formula for determining if
altruistic acts are favored.
The Evolution of Social Systems
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A social system is a group of organisms of the same
species that are organized in a cooperative manner.
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Individuals benefit from social living, and the benefits
increase with the numbers of organisms.
Social insects are composed of different castes that each
have specialized tasks.
Vertebrate social systems are less rigidly organized and
cohesive and are influenced by food availability and
predation
How does Behavioral Ecology
correlate to the AP THEMES?
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Evolution – behavior patterns are selected
for by environmental factors.
Interdependence in nature – animals live with
other animals of the same and different
species. To survive, they must interact with
each other.
Preparing for the Unit Test
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Use the ppt as a guide and FIND specific
experiments or examples that correspond to
the ideas on the slide.
Use the review questions at the end of this
ppt.
Use the questions at the end of this ppt to
help you think scientifically and connect
concepts.
Review Questions
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Describe two studies that suggest behavior has a genetic basis.
Describe an experiment that supports that the environment (nurture)
influences behavior.
Describe two types of associative learning.
Give examples of the different types of communication among
members of a social group.
What is territoriality, and how might it increase fitness?
Name three types of reproductive strategies, and describe how they
can be related to the environment.
What is sexual selection, and why does it foster female choice and
male competition during mating?
Give examples (and supportive experiments) of behaviors that appear
to be altruistic but actually increase the inclusive fitness of an
individual.
Thinking Scientifically
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Meerkats are said to exhibit altruistic
behavior because certain members of a
population act as sentries. How would you
test the hypothesis that sentries are engaged
in altruistic behavior?
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Sources for this ppt.
Biology 7th edition by Campbell and Reece
Biology 10th edition by Sylvia Mader
Biology 8th edition by Raven and Johnson