Transcript Chapter 6 Primate Behavior

Chapter 6
Primate Behavior
Chapter Outline
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Importance of Primate Study
Evolution of Behavior
Nonhuman Primate Social Behavior
Reproduction and Reproductive Strategies
Mothers and Infants
Nonhuman Primate Cultural Behavior
Primate Cognitive Abilities
The Primate Continuum
Importance of Primate Studies
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Modern African apes and humans last shared a
common ancestor between 5 and 8 m.y.a.
Only within the last 4 decades have nonhuman
primates been studied.
Many species, such as arboreal monkeys have
scarcely been studied at all.
Primate Socioecology
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Socioecology studies the relationship
between social behavior and the natural
environment.
One assumption is that components of
ecological systems evolved together.
To understand how one component works, it is
necessary to determine the species
relationships with their environment.
Environmental Factors
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Quality and quantity of foods
Distribution of food resources, water, predators
and sleeping sites
Activity patterns (diurnal, nocturnal)
Relationship with other species
Impact of human activities
Socioecology and Predation
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Multimale and multifemale groups have an
advantage when predation pressure is high.
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Adult males may join forces to attack predators.
Savannah baboons have been known to kill
domestic dogs and attack leopards and lions.
Solitary foraging may be due to diet and
distribution of resources or predator avoidance.
Evolutionary Perspective
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Natural selection acts on behavior just as it
acts on physical characteristics.
Behavior is a phenotypic expression and genes
code for specific behaviors.
Natural selection has a role in shaping primate
behavior.
Criticism of the
Evolutionary Perspective
Little data on:
 The social behavior of large groups of animals.
 Genetic relatedness through the male line.
 Assigning reproductive costs and benefits to
particular behaviors.
 The genetics of primate social behavior.
Dominance Status
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Factors that influence status:
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Sex
Age
Aggression
Time in the group
Intelligence
Motivation
Mother’s social position
Communication
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Raised body hair is an example of an autonomic
response.
Vocalizations and branch shaking are examples of
deliberate communication.
Reassurance is communicated through hugging or
holding hands.
The fear grin, seen in all primates, indicates fear and
submission.
Displays communicate emotional states.
Aggression
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Primates might defend a core area within their
permanent home.
Jane Goodall witnessed unprovoked, brutal
attacks of chimpanzees by other chimpanzees.
Territoriality and acquisition of females are the
motives suggested for chimpanzee male
aggression.
Affiliative Behaviors
Reinforce bonds between individuals and
enhance group stability:
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Grooming reinforces social bonds.
Hugging, kissing and grooming are all forms used in
reconciliation.
Relationships are crucial to nonhuman primates and
the bonds between individuals can last a lifetime.
Altruism, behaviors that benefit another while posing
risk to oneself, are common in primate species.
Patterns of Reproduction
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In most primate societies, sexual behavior is
tied to the female’s reproductive cycle.
Permanent bonding is not common among
nonhuman primates.
Male and female Bonobos may mate even
when the female is not in estrus, a behavior
that is not typical of chimpanzees.
Reproductive Strategies
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Behavioral patterns that contribute to individual
reproductive success.
Primates produce only a few young in whom
they invest a tremendous amount of parental
care. (k –selected)
Male competition for mates and mate choice in
females are both examples of sexual selection.
Mothers and Infants
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The basic social unit among all primates is the female
and her infants.
Except in species in which monogamy or polyandry
occur, males do not participate in rearing offspring.
Monkeys raised without a mother were not able to form
lasting affectional ties.
The mother-infant relationship is often maintained
throughout life.
Nonhuman Primate
Cultural Behavior
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Cultural behavior is learned and passed from
one generation to the next.
Chimpanzee culture includes tools such as
termite fishing sticks and leaf sponges.
Primate Cognitive Abilities
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Social interactions and problem-solving
abilities demonstrate primate intelligence.
Vervet monkeys have three different
vocalizations to indicate types of predators.
The fact that apes can’t speak has more to do
with their anatomy and the language related
structures of the brain than intelligence.
The Primate Continuum
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Human brains are larger than primate brains, but the
neurological processes are functionally the same.
That humans are part of an evolutionary continuum is
the basis for animal research, yet we cage nonhuman
primates without regard for their needs.
Nonhuman primates should be maintained in social
groups and introduced to habitat enrichment programs.