Primate Behaviors
Two Paradigms of Study
I.
A.
B.
C.
Socioecology
Sociobiology
Sociobiology Criticisms
Important Primate Behaviors
II.
A.
B.
C.
D.
E.
F.
G.
H.
Dominance
Communication
Aggression
Affiliative Behaviors
Reproduction and Reproductive Strategies
Mothers and Infants
Nonhuman Primate Cultural Behavior
Primate Cognitive Abilities
I. Two Primate Study Paradigms
A. Socioecology focuses on the relationship between
social behavior and the natural environment.
Favors selection for the individual’s daily survival.
B. Sociobiology focuses on the genetic predisposition
to behaviors and those behaviors’ enhancement of
reproductive success.
1. One of the underlying assumptions is that various
components of ecological systems evolved together.
2. To understand how one component works, it is
necessary to determine the species relationships with
numerous environmental factors.
I A. Socioecology
Primatologists consider the following
environmental factors:
1.
a.
b.
c.
d.
e.
Quality and quantity of different foods
Distribution of food resources, water, predators
and sleeping sites
Activity patterns (diurnal, nocturnal)
Relationship with other species
Impact of human activities
I A. Socioecology, cont.
2.
3.
Environmental factors such as resource availability
and predation have a strong influence on group size
and structure.
Multimale and multifemale groups have an advantage
when predation pressure is high.
Adult males may join forces to chase and attack predators.
Savannah baboons have been known to kill domestic dogs
and to attack leopards and lions.
4.
Solitary foraging may be related to diet and
distribution of resources or predator avoidance.
I B. Sociobiology
1.
2.
3.
Natural selection acts on behavior in the same
way it acts on physical characteristics.
Behavior is a phenotypic expression and
genes code for specific behaviors.
This approach provides an opportunity to study
the effects natural selection has had in shaping
primate behavior.
I C. Criticism of Sociobiology
1.
2.
3.
4.
5.
Lack of long-term data on the demography and social
behavior of large groups of animals.
Lack of long-term data on the distribution of
resources in time and space.
Nearly complete absence of information on genetic
relatedness through the male line.
Difficulty in assigning reproductive costs and benefits
to particular behaviors.
Almost total ignorance of the genetics of primate
social behavior.
II A. Dominance
Many primate societies are organized into
dominance hierarchies.
Dominance hierarchies impose a degree of order
within the group.
Dominant animals have priority access to food and
mating partners.
Many factors influence dominant status: sex, age,
level of aggression, time spent in the group,
intelligence, motivation and sometimes the mother’s
social position.
II B. Communication
Communication is universal among animals:
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.
II C. Aggression
Home range is the area where a primate lives
permanently. Within this is the core area that a
primate might defend.
Jane Goodall and her colleagues witnessed
unprovoked and brutal attacks of chimpanzees
by other chimpanzees.
Territoriality and acquisition of females are the
motives suggested for chimpanzee male
aggression.
II D. Affiliative Behaviors
These behaviors reinforce bonds between
individuals and enhance group stability:
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.
II E. Patterns of Reproduction
In most primate societies, sexual behavior is tied to the
female’s reproductive cycle (perineal swelling).
Permanent bonding is not common among nonhuman
primates.
The temporary relationship
for mating purposes is called
a consortship.
Male and female Bonobos
may mate even when the
II E. Reproductive Strategies
Reproductive strategies are behavioral patterns
that contribute to individual reproductive
success.
Primates are k-selected; they produce only a
few young in whom they invest a tremendous
amount of parental care.
Male competition for mates and mate choice in
females are both examples of sexual selection.
II F. Mothers and Infants
The basic social unit among all primates is the female
and her infant(s).
Except in species in which monogamy or polyandry
occur, males do not participate in rearing.
Monkeys raised with no mother are not
able to form lasting affectional ties.
The mother-infant relationship is often
maintained throughout life.
II G. Primate Cultural Behavior
Biological anthropologists use the term
culture in referring to nonhuman primates as
well as humans.
Cultural behavior is learned and passed from
one generation to the next.
Chimpanzee culture includes tools such as
termite fishing sticks and leaf sponges.
II H. Primate Cognitive Abilities
Primate social interactions and problem-solving
abilities demonstrate their intelligence.
Vervet monkeys have three different
vocalizations to indicate types of predators.
The fact that apes can’t speak has more to do
with the anatomy of the vocal tract and the
language related structures of the brain than
intelligence.
The Primate Continuum
Although human brains are larger than primate brains,
the neurological processes are functionally the same.
The fact that humans are part of an evolutionary
continuum is the basis for animal research, yet we
continue to cage nonhuman primates with little regard
for the needs they share with us.
Nonhuman primates should be maintained in social
groups and introduced to habitat enrichment programs.