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Chapter 51
Behavioral Ecology
PowerPoint Lectures for
Biology, Seventh Edition
Neil Campbell and Jane Reece
Lectures by Chris Romero
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings
• Concept 51.1: Behavioral ecologists distinguish
between proximate and ultimate causes of
behavior
• The scientific questions that can be asked
about behavior can be divided into two classes
– Those that focus on the immediate stimulus
and mechanism for the behavior
– Those that explore how the behavior
contributes to survival and reproduction
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What Is Behavior?
• Behavior
– Is what an animal does and how it does it
– Includes muscular and nonmuscular activity
• Learning
– Is also considered a behavioral process
Dorsal fin
Figure 51.2
Anal fin
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Proximate and Ultimate Questions
• Proximate, or “how,” questions about behavior
– Focus on the environmental stimuli that trigger
a behavior
– Focus on the genetic, physiological, and
anatomical mechanisms underlying a
behavioral act
• Ultimate, or “why,” questions about behavior
– Address the evolutionary significance of a
behavior
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Fixed Action Patterns
• A fixed action pattern (FAP)
– Is a sequence of unlearned, innate behaviors
that is unchangeable
– Once initiated, is usually carried to completion
• A FAP is triggered by an external sensory
stimulus
– Known as a sign stimulus
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• In male stickleback fish, the stimulus for attack
behavior
– Is the red underside of an intruder
(a) A male three-spined stickleback fish shows its red underside.
Figure 51.3a
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• When presented with unrealistic models
– As long as some red is present, the attack
behavior occurs
(b) The realistic model at the top, without a red underside, produces no
aggressive response in a male three-spined stickleback fish. The
other models, with red undersides, produce strong responses.
Figure 51.3b
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• Proximate and ultimate causes for the FAP
attack behavior in male stickleback fish
BEHAVIOR: A male stickleback fish attacks other male sticklebacks that invade its nesting
territory.
PROXIMATE CAUSE: The red belly of the intruding male acts as a sign stimulus
that releases aggression in a male stickleback.
Figure 51.4
ULTIMATE CAUSE: By chasing away other male sticklebacks, a male decreases
the chance that eggs laid in his nesting territory will be fertilized by another male.
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Imprinting
• Imprinting is a type of behavior
– That includes both learning and innate
components and is generally irreversible
• Imprinting is distinguished from other types of
learning by a sensitive period
– A limited phase in an animal’s development
that is the only time when certain behaviors
can be learned
• An example of imprinting is young geese
– Following their mother
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• There are proximate and ultimate causes for
this type of behavior
BEHAVIOR: Young geese follow and imprint on their mother.
PROXIMATE CAUSE: During an early, critical developmental stage, the young
geese observe their mother moving away from them and calling.
ULTIMATE CAUSE: On average, geese that follow and imprint on their mother
receive more care and learn necessary skills, and thus have a greater chance of
surviving than those that do not follow their mother.
Figure 51.5
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• Conservation biologists have taken advantage
of imprinting
– In programs to save the whooping crane from
extinction
Figure 51.6
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• Concept 51.2: Many behaviors have a strong
genetic component
• Biologists study the ways both genes and the
environment
– Influence the development of behavioral
phenotypes
• Behavior that is developmentally fixed
– Is called innate behavior and is under strong
genetic influence (directed movement)
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Kinesis
• A kinesis
– Is a simple change in activity or turning rate in
response to a stimulus
• Sow bugs
– Become more active in dry areas and less
active in humid areas
Dry
open
area
(a) Kinesis increases the chance that a sow bug
will encounter and stay in a moist environment.
Figure 51.7a
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Moist
site
under
leaf
Taxis
• A taxis
– Is a more or less automatic, oriented
movement toward or away from a stimulus
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Migration
• Many features of migratory behavior in birds
– Have been found to be genetically
programmed
Figure 51.8
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Animal Signals and Communication
• In behavioral ecology
– A signal is a behavior that causes a change in
another animal’s behavior
• Communication
– Is the reception of and response to signals
– Visual, auditory, chemical, tactile, and
electrical signals
– Chemical communication: odors (pheremones)
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Pheromones
• When a minnow or catfish is injured
– An alarm substance in the fish’s skin disperses
in the water, inducing a fright response among
fish in the area
(a) Minnows are widely dispersed in an aquarium
before an alarm substance is introduced.
Figure 51.9a, b
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(b) Within seconds of the alarm substance being
introduced, minnows aggregate near the
bottom of the aquarium and reduce their movement.
Genetic Influences on Mating and Parental Behavior
• A variety of mammalian behaviors
– Are under relatively strong genetic control
• Research has revealed the genetic and neural basis
– For the mating and parental behavior of male prairie
voles
Figure 51.11
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• Concept 51.3: Environment, interacting with an
animal’s genetic makeup, influences the
development of behavior
• That environmental conditions modify many of
the same behaviors
• Learning is the modification of behavior
– Based on specific experiences
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Habituation
• Habituation
– Is a loss of responsiveness to stimuli that
convey little or no information
Spatial Learning
• Spatial learning is the modification of behavior
– Based on experience with the spatial structure
of the environment
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• In a classic experiment, Niko Tinbergen
– Showed how digger
wasps use landmarks
to find the entrances
to their nests
EXPERIMENT
A female digger wasp excavates and cares for four
or five separate underground nests, flying to each nest daily with food
for the single larva in the nest. To test his hypothesis that the wasp
uses visual landmarks to locate the nests, Niko Tinbergen marked one
nest with a ring of pinecones.
Nest
After the mother visited the nest and flew away, Tinbergen
moved the pinecones a few feet to one side of the nest.
RESULTS
When the wasp returned, she flew to the center of
the pinecone circle instead of to the nearby nest. Repeating the
experiment with many wasps, Tinbergen obtained the same results.
Nest
CONCLUSION
Figure 51.14
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No Nest
The experiment supported the hypothesis
that digger wasps use landmarks to keep track of their nests.
Cognitive Maps
• A cognitive map
– Is an internal representation of the spatial
relationships between objects in an animal’s
surroundings
Associative Learning
• In associative learning
– Animals associate one feature of their
environment with another
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• Classical conditioning is a type of associative
learning
– In which an arbitrary stimulus is associated
with a reward or punishment
Before stimulus
Influx of alarm substances
Influx of water alone
Influx of pike odor
Day 1
Relative activity level
Day 3
Figure 51.15
Control
group
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Experimental
group
Control
group
Experimental
group
• Operant conditioning is another type of
associative learning
– In which an animal learns to associate one of
its behaviors with a reward or punishment
Figure 51.16
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Cognition and Problem Solving
• Cognition is the ability of an animal’s nervous
system
– To perceive, store, process, and use
information gathered by sensory receptors
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• Problem solving can be learned
– By observing the behavior of other animals
Figure 51.17
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• Concept 51.4: Behavioral traits can evolve by
natural selection
• When behavioral variation within a species
Time to attack (seconds)
– Corresponds to variation in the environment, it
may be evidence of past evolution
50
Desert
grasslan
d
populatio
n
Riparian
40
populatio
n
30
20
10
0
Field
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Lab-raised
generation 1
Lab-raised
generation 2
• Migratory orientation of wintering adult birds
captured in Britain
– Was very similar to that of laboratory-raised birds
N
BRITAIN
W
E
S
(b) Wintering blackcaps captured in Britain and their laboratory-raised
offspring had a migratory orientation toward the west, while
young birds from Germany were oriented toward the southwest.
N
Young
from SW
Germany
Mediterranean
Sea
Figure 51.21b
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E
W
S
Adults from
Britain and
F1 offspring
of British
adults
• Concept 51.5: Natural selection favors
behaviors that increase survival and
reproductive success
• Reto Zach
– Conducted a cost-benefit analysis of feeding
behavior in crows
• The crows eat molluscs called whelks
– But must drop them from the air to crack the
shells
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Risk of Predation
• Research on mule deer populations
– Has shown that predation risk affects where
the deer choose to feed
Predation
risk
Relative deer use
60
15
50
40
10
30
20
5
10
0
0
Open
Figure 51.24
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Forest edge
Habitat
Forest interior
Relative deer use
Predation occurrence (%)
70
20
Mating Behavior and Mate Choice
• Mating behavior
– Is the product of a form of natural selection
called sexual selection
– The mating relationship varies a great deal
from species to species
– mating is often promiscuous
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• In monogamous relationships
– One male mates with one female
•
The needs of the young
–
•
The certainty of paternity
–
(a) Since monogamous species, such as these
trumpeter swans, are often monomorphic, males
and females are difficult to distinguish using
external characteristics only.
Figure 51.25a
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Are an important
factor constraining the
evolution of mating
systems
Influences parental
care and mating
behavior
Sexual Selection and Mate Choice
• In intersexual selection
– Members of one sex
choose mates on the basis
of particular characteristics
Figure 51.27
• Intrasexual selection
– Involves competition
among members of one
sex for mates
Figure 51.30
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• Concept 51.6: The concept of inclusive fitness
can account for most altruistic social behavior
– Many social behaviors are selfish
– Occasionally, altruistic behaviors arise
Figure 51.33
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Inclusive Fitness
• Altruistic behavior can be explained by
inclusive fitness
– The total effect an individual has on
proliferating its genes by producing its own
offspring and by providing aid that enables
close relatives to produce offspring
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Hamilton’s Rule and Kin Selection
• Hamilton proposed a quantitative measure
– For predicting when natural selection would
favor altruistic acts among related individuals
•
The three key variables in an
altruistic act are
–
The benefit to the recipient
–
The cost to the altruist
–
The coefficient of
relatedness
Parent A
Parent B

OR
1/
1/
2
(0.5)
probab
ility
Figure 51.34
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Sibling 1
2
(0.5)
probab
ility
Sibling 2
• Natural selection favors altruism when the
benefit to the recipient
– Multiplied by the coefficient of relatedness
exceeds the cost to the altruist
– This inequality is called Hamilton’s rule
• Kin selection is the natural selection
– That favors this kind of altruistic behavior by
enhancing reproductive success of relatives
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Reciprocal Altruism
• Altruistic behavior toward unrelated individuals
– Can be adaptive if the aided individual returns
the favor in the future
Social Learning
• Culture can be defined as a system of information
transfer through observation or teaching
Mate Choice Copying
– Is a behavior in which individuals in a
population copy the mate choice of others
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Social Learning of Alarm Calls
• Vervet monkeys
– Produce a complex set of alarm calls
Figure 51.37
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Evolution and Human Culture
• Human behavior, like that of other species
– Is the result of interactions between genes and
environment
• However, our social and cultural institutions
– May provide the only feature in which there is
no continuum between humans and other
animals
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