Deck 6: Primate Mating Systems

Question 1

Because behavioral strategies are thought to be the product of natural selection, they should increase

A) reproductive success.
B) the cost-to-benefit ratio.
C) adaptations.
D) trade-offs.

Answer 1

A

Question 2

The reproductive success of primate females is constrained mainly by

A) the energetic costs of pregnancy and lactation.
B) the availability of males.
C) a female's genetic makeup.
D) a female's ability to attract mates.

Answer 2

A

Question 3

To better understand primate societies, we need to investigate the way primates find mates and care for their offspring. This is known as their

A) social organization.
B) social system.
C) mating system.
D) reproductive strategy.

Answer 3

C

Question 4

For most primates reproductive success of a primate female depends largely on

A) group size and composition.
B) her ability to acquire nutritive resources.
C) her ability to coerce males into investing in offspring.
D) male protection.

Question 5

Primate females always invest in their young because

A) primate males do not have the appropriate neurological foundation.
B) they are committed to parental investment by their physiology.
C) they produce large, nutrient-rich gametes.
D) parenting effort is equal to mating effort.

Question 6

Which of the following best describes a particular primate mating system and reproductive behavior?

A) In baboons females compete with other females for mating opportunities with prime males, whereas males rarely compete with each other.
B) Male preference can influence female reproductive success in groups where there are multiple males.
C) In most pair-bonded species, both males and females care for offspring.
D) In polyandrous species, both males and females have equal opportunities to mate.

Question 7

If animal A outranks animals B and C, and B outranks C, then the dominance relationships are

A) unlikely to produce sexual selection.
B) unstable.
C) transitive.
D) explained by intersexual competition.

Question 8

Primiparous females

A) reproduce at faster rates than multiparous females.
B) give birth to only one infant in their lifetime.
C) experience greater infant mortality than multiparous females.
D) have shorter interbirth intervals than multiparous females.

Question 9

Because primates are mammals, what can you predict about their reproductive strategy?

A) Resource competition forces pair-bonding.
B) Alpha males sire almost all of the offspring.
C) Males assist in rearing offspring in most cases.
D) Females are obligated to invest heavily in their offspring through pregnancy and lactation.

Question 10

Primates have longer gestation periods than other mammals relative to body size because

A) they produce smaller offspring relative to body size than other mammals.
B) they have larger brains, relative to body size, than other mammals.
C) they have access to more nutritive resources than other mammals.
D) they do not possess the morphology for external gestation.

Question 11

In the language of adaptive explanations, what is meant by the term "strategy"?

A) A mechanism that leads to particular behaviors in particular contexts
B) A conscious decision to make adaptive behavioral choices
C) A conscious decision to make adaptive or nonadaptive behavioral choices
D) A behavior of higher animals, such as mammals

Question 12

The majority of primate species are not pair-bonded. Therefore, we can predict that

A) both sexes will care for offspring equally.
B) neither sex will care for offspring.
C) males will provide more care for offspring than will females.
D) females will provide more care for offspring than will males.

Question 13

In the language of adaptive explanations, cost and benefit refer to the impact of behaviors on the animal's

A) overall health.
B) reproductive success.
C) foraging success.
D) social relationships.

Question 14

Which of the following statements about female primate reproductive success is NOT supported by the evidence?

A) The longer a female lives, the more offspring she will likely have.
B) Past a certain age, female primates stop reproducing, so it does not matter how long they live.
C) Younger females have less success with raising offspring because the female is not fully grown and continues to demand energy for her own survival that might otherwise be invested in offspring.
D) Among primates, humans are unusual in that females stop reproducing abruptly when they get older and have a potentially long postreproductive period.

Question 15

Which of the following statements is true?

A) Dominance rank is not a good predictor of female reproductive success.
B) Young females tend to reproduce more often than older females because they are in better physical condition.
C) Variation in longevity is a major contributor to variation in lifetime fitness among females.
D) Females in multimale groups have more offspring than females in one-male units.

Question 16

Which of the following statements is true?

A) Patterns of courtship, mate choice, and parental care vary greatly within the primate order.
B) The reproductive strategies of living primates are not influenced by their phylogenetic heritage as mammals.
C) Studies of primate reproductive behavior cannot help us understand how evolutionary forces shaped the reproductive strategies of our hominin ancestors.
D) The same factors limit male and female reproductive success.

Question 17

The relative amount of parental care

A) can affect all aspects of social behavior and some aspects of morphology.
B) is virtually the same across the primate order.
C) does not influence reproductive strategies.
D) is determined directly by dominance hierarchy.

Question 18

Female fertility is greatest in

A) young females.
B) middle-age females.
C) older females.
D) primiparous females.

Question 19

Unequal parental investment is favored when

A) resource competition is high for females.
B) the cost of acquiring additional mates is low for males.
C) the cost of acquiring additional mates is high for males.
D) the fitness of offspring raised by two parents is much higher than the fitness of offspring raised by one parent.

Question 20

Which of the following plays a crucial role in our understanding of primate societies?

A) Metabolism
B) Diet
C) Mating systems
D) Physiology

Question 21

The single factor that can compensate for low rank and its corresponding decrease in reproductive success is

A) age at maturity.
B) choice of mates.
C) positive social relationships.
D) longevity.

Question 22

Intrasexual selection favors traits that

A) enhance direct competition among individuals of the same sex.
B) are attractive to the opposite sex.
C) increase survival.
D) are easily adapted to change.

Question 23

Which type of social group has the largest relative testis size?

A) Pair bonded
B) One-male, multifemale
C) Multimale, multifemale
D) One female, multimale

Question 24

Which type of social group has the most sexual dimorphism in canine size?

A) Pair bonded
B) One-male, multifemale
C) Multimale, multifemale
D) One female, multimale

Question 25

The reproductive success of primate females depends upon

A) interbirth interval variation.
B) group composition and size.
C) predation pressure.
D) the number and quality of offspring.

Question 26

Which of the following is true of primates in general?

A) Pair-bonded groups have the least amount of sexual dimorphism in body size.
B) One-male, multifemale groups have less dimorphism in body size than do pair-bonded species.
C) Multimale, multifemale groups are not dimorphic in body size.
D) Multimale, multifemale groups tend to have greater sexual dimorphism than one-male, multifemale groups.

Question 27

Large body sizes that require more energy and weaponry that can cause severe injury demonstrate that

A) sexual selection is stronger than natural selection.
B) natural selection is stronger than sexual selection.
C) male reproductive success varies less than female reproductive success.
D) intersexual selection is strong in primates.

Question 28

Which of the following statements is true of a group with a female dominance hierarchy?

A) Low-ranking howler females stay in their natal groups when dispersal is difficult.
B) There is no survival difference between the offspring of high- and low-ranking female long-tailed macaques.
C) When subordinate marmoset or tamarin females breed, their infants may be killed by dominant females that have infants of their own.
D) high-ranking females maintain low levels of body fat.

Question 29

Dominance hierarchies occur among females when

A) females are unrelated.
B) groups are small.
C) food is particularly abundant.
D) food is clumped and defensible.

Question 30

When compared with low-ranking females, high-ranking females may

A) obtain larger quantities of food.
B) spend less energy to reproduce.
C) travel farther to feed.
D) spend more energy in courtship rituals.

Question 31

Female nonhuman primates often begin to reproduce before they are fully grown. Empirical evidence supports the idea that these young females

A) can achieve high fertility and low infant mortality equivalent to middle-age and older females.
B) will have shorter interbirth intervals than fully grown females.
C) will have lower fertility than middle-age females.
D) will not achieve full adult size in their lifetime.

Question 32

When male primates disperse, they often move to groups that are nearby because

A) those groups usually have the best females to mate with.
B) male primates prefer not to travel long distances alone.
C) the cost of dispersal is high due to predation risk and poor access to resources.
D) they know the neighboring groups, so they do not have to compete as fiercely for access.

Question 33

In social groups in which there is mate guarding,

A) females groom males more frequently.
B) males have little parental investment.
C) extrapair copulations result in a percentage of offspring.
D) genetic testing has shown it is effective against extrapair copulation.

Question 34

Male reproduction is limited by

A) the number of sex cells a male produces.
B) parental investment and infant care.
C) the number of fertile females.
D) food availability.

Question 35

Intersexual selection

A) favors traits that enhance direct competition among individuals.
B) favors traits that are attractive to the opposite sex.
C) is a direct result of the environment.
D) produces variation in survival between the sexes.

Question 36

Primate mothers modify their investment in their offspring

A) when offspring can give alarm calls.
B) with the mother's need to conserve resources.
C) after they conceive the next offspring.
D) depending on their mating system.

Question 37

Many primate females form dominance hierarchies because

A) they compete with one another over access to mates.
B) societies run more smoothly with dominance hierarchies.
C) some females do not need as many resources as others.
D) they compete with one another over access to food.

Question 38

Primate researchers have found a positive correlation between female dominance rank and

A) number of births per year.
B) length of interbirth interval.
C) infant mortality.
D) rank of associates.

Question 39

Which of the following characteristics would you expect to find in a species in which there is extreme competition among males for access to females?

A) Drab pelage
B) Equal body size
C) Small canine teeth
D) Specialized weaponry

Question 40

Sexual selection

A) favors phenotypes that help survival.
B) produces the same characteristics in both sexes.
C) enhances offspring survival.
D) favors traits that increase the ability to compete for mates.

Question 41

Define sexual selection, and compare/contrast its two main forms: intersexual selection and intrasexual selection.

Question 42

How does the threat of infanticide influence male-female relationships in baboons? Include in your answer a discussion of mating effort and parenting effort.

Question 43

Explain the relationship between body, canine, and testis size and the following forms of social organization: (a) pair-bonded groups; (b) one-male, multifemale groups; and (c) multimale, multifemale groups.

Question 44

Through genetic testing and behavioral research, researchers have shown that

A) low-ranking males mate guarded more often and sired more offspring.
B) high-ranking males sired more offspring than low-ranking males.
C) low-ranking males were outcompeted during female cycles and did not sire any offspring.
D) high-ranking males mate guarded females but only during cycles when they did not conceive.

Question 45

As an evolutionary biologist, how would you explain the relationship between animal behavior and strategy, cost, and benefit to a layperson? Make sure to define what you mean by "strategy."

Question 46

Recent studies indicate that high-ranking male primates have

A) lower reproductive success than low-ranking or alien males.
B) higher reproductive success than low-ranking or alien males.
C) reproductive success equal to that of low-ranking and alien males.
D) limited reproductive success because of the stress of high rank.

Question 47

What is the evidence demonstrating the importance of socializing for female primates?

Question 48

Discuss the better documented counterstrategies to infanticide evolved by female primates, and give specific primate examples from the reading.

Question 49

In gelada baboon social units, "follower" males

A) reproduce more successfully, independent of rank.
B) are found in groups with small numbers of females.
C) do not increase the tenure of "leader" males.
D) sire approximately 17% of offspring in the group.

Question 50

Male primates commit infanticide in one-male, multifemale groups because

A) it enhances male attractiveness to females.
B) females without nursing infants resume sexual receptivity.
C) females do not want infants sired by a nonalpha male.
D) they want to limit the number of males in their group.

Question 51

If infanticide is a reproductive strategy for males, then

A) males should kill all the infants already in the group when they take over.
B) males should kill all the infants already in the group, regardless of where the mothers are in their cycle.
C) infanticide should be associated with group size and composition.
D) infanticide should be correlated with a change in male residence or status in the group.

Question 52

Explain why it is important that we study and understand reproductive strategies of animals, and primates specifically.

Question 53

How could infanticide be seen as a male reproductive strategy? Why is infanticide more prevalent in species that form one-male, multifemale groups than in multimale, multifemale groups? Is there evidence that this is an adaptive strategy? Explain your answer.

Question 54

Direct male-male competition is most intense in

A) pair-bonded groups.
B) one-male, multifemale groups.
C) multimale, multifemale groups.
D) bachelor groups.

Question 55

How can dominance status affect female reproductive success? Illustrate your answer with specific primate examples.

Question 56

Males can reduce the cost of dispersal by

A) dispersing with peers or joining all-male groups.
B) dispersing alone but staying close to their original groups.
C) dispersing at night close to other groups.
D) dispersing far from their natal group.

Question 57

Dominance hierarchies are seen in multimale, multifemale groups because hierarchies

A) give low-ranking males a chance to compete.
B) let females know which males to mate with.
C) mediate male-male competition.
D) prevent infanticide.