Transcript females

Chapter 45
Animal Behavior
Animal Behavior
Outline
Nature versus Nurture: Genetic Influences
Nature versus Nurture: Environmental Influences
Learning
Adaptive Mating Behavior
Female Choice
Male Competition
Dominance Hierarchy
Territoriality
Animal Communication
Sociobiology and Animal Behavior
Altruism versus Self-Interest
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Animal Behavior
Genetic Basis
Behavior - observable and coordinated responses to
environmental stimuli
Nature (inherited) versus nurture (environmental)
questions are still debated
Genes influence development of neural and hormonal
mechanisms controlling behavior
Studies on identical twins separated at birth
- Can be used to determine extent of inherited behavior
- Sometimes remarkably similar in preferences, taste,
personality tests, etc.
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Nest Building Behavior in Lovebirds
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Feeding Behavior in Garter Snakes
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Animal Behavior
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Behavior Undergoes Development
Some behaviors seem to be stereotyped
Fixed Action Patterns (FAP’s)
- Originally assumed to be elicited by a sign stimulus
- Increasingly thought to develop after practice
Animal Behavior
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The Phenomenon of Learning
Operant Conditioning
Gradual strengthening of stimulus-response
corrections
Trick-training in birds
Imprinting
Imitate behavior observed during sensitive period
Goslings follow any moving object after birth
Animal Behavior
The Phenomenon of Learning
Song Learning in Birds
Avian brain is especially sensitive to acoustical
stimuli during a sensitive period
Social experience appears to have an even
stronger influence over development of singing
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Pecking Behavior in Laughing Gulls
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Classical Conditioning
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Animal Behavior
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Behavior Is Adaptive
Sexual selection - Adaptive changes in females
and males that lead to differential reproductive
success
Raggiana Bird of Paradise
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Animal Behavior
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Female Choice
Courtship displays help males and females
recognize each other for successful mating
Good Genes Hypothesis
- Females benefit from selective choice by securing
sperm with good genes
Run-Away Hypothesis
- Females choose mates on the basis of traits that
make them attractive to females
Animal Behavior
Male Competition
Is access to mating is worth the cost of
competition among males
Question is studied by cost-benefit analyses
Do positive effects (benefits) outweigh negative
effects (costs)?
- If yes
 The
behavior is evolutionarily stable
 The behavior will survive or increase
- If no
 The
behavior is evolutionarily UNstable
 The behavior will decrease or disappear
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Animal Behavior
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Dominance Hierarchy
Males and females have separate dominance
hierarchies
Higher-ranking individuals have greater access to
essential resources
Baboons form temporary consort pairs with
females
- Males may monopolize estrous females
- Or may assist females or form friendship groups to
secure future matings
A Male Olive Baboon Displaying Full Threat 16
Animal Behavior
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Territoriality
Territoriality is protecting an area against other
individuals
Red Deer Stags (males) compete for groups of
hinds (females)
Hinds only mate with one stag
Harem Master must be large and powerful to fight
off challengers
- Means less body fat
- May be more likely to starve in bad times, and have
shorter life expectancy
Competition Between Male Red Deer
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King Hussein and Family
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Animal Behavior
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Animal Societies
Society - a cooperative organization that extends
beyond sexual and parental interests
The Queen Ant
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Animal Behavior
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Altruism versus Self-Interest
Altruism
Behavior that involves a reduction in direct fitness
Loss may be compensated by an increase in
indirect fitness
Inclusive fitness includes
Reproductive fitness of self, and
Reproductive fitness of relatives
Genetic relatedness may underlie many/most
acts of apparent altruism
Inclusive Fitness
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Animal Behavior
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Communicative Behavior
Communicative Behavior
Chemical
- Pheromones designate chemical signals that are
passed between members of the same species
Auditory
Faster than chemical communication
Can be modified by loudness, pattern, repetition,
and duration
Visual
Used by species active during the day
- Contests between males make use of threat
postures
- Saves energy by avoiding fighting
Use of a Pheromone
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A Chimpanzee With a Researcher
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Animal Behavior
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Communicative Behavior
Tactile
Occurs when one animal touches another
- Gull chicks peck at the parent’s beak in order to
induce the parent to feed them
- Foraging honeybees
 Return
to the hive and perform a waggle dance
 Indicates
the distance and direction of a food source
Grooming Among Baboons
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Communication Among Bees
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Animal Behavior
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Sociobiology and Animal Behavior
Sociobiology
Applies the principles of evolutionary biology to
the study of behavior in animals
Assumes individuals derive benefits from living in
a society that outweigh costs
- Advantages include
 reproductive
 Predator
avoidance
 Assistance
 Finding
success
in rearing offspring
food
Animal Behavior
Sociobiology and Animal Behavior
Societal Disadvantages
Crowding
- Resource allocation
- Spread of disease
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Animal Behavior
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Nest Helpers
Green Wood-hoopoes
One breeding pair per flock
- Other sexually mature members may help feed and
protect fledglings and protect the home territory
- Helper is contributing to survival of its own kin
- Helper is more likely than nonhelper to inherit
parental territory