Mating Systems

Question 1

Social monogamy

Answer 1

a female and female form a social bond, often for a breeding season or longer, but may still engage in extra-pair copulations

Question 2

Genetic monogamy

Answer 2

a truly exclusive reproductive relationship with no extra-pair mating

Question 3

Necessity for paternal care

Answer 3

when parental investment increases offspring survival, monogamy is favored (tamarins and marmosets require paternal care due to the high energetic demands of raising twins)

Question 4

Infanticide risk

Answer 4

if males cannot increase reproductive success by killing offspring and mating with the female sooner, monogamy is more likely (some primates avoid infanticide through monogamous pair bonding)

Question 5

Mate guarding

Answer 5

when females are scarce or widely dispersed, males may benefit from guarding one mate rather than competing for multiple (klipspringers and clown shrimp exhibit this strategy)

Question 6

Polygyny

Answer 6

one male mates with multiple females (most common mating system among vertebrates)

Question 7

Resource defense

Answer 7

males defend resources that attract females (African cichlids defend breeding sites)

Question 8

Harem defense

Answer 8

males guard groups of females (sika deer form harems, which males aggressively protect)

Question 9

Scramble competition

Answer 9

when females are widely dispersed or only briefly receptive, males compete in a race to mate (orangutangs use this strategy due to the scattered distribution of females)

Question 10

Lek

Answer 10

males gather in groups and perform elaborate displays, with only a few males successfully mating (sage grouse form leks where dominant males secure most matings)

Question 11

Polyandry

Answer 11

one female mates with multiple males which increases genetic diversity, ensures fertility insurance, and provides material benefits (grey foam nest treefrogs lay eggs fertilized by multiple males, improving offspring survival

Question 12

Polygynandry

Answer 12

multiple males and females form breeding groups (acron woodpeckers exhibit cooperative breeding with shared parenting)

Question 13

Promiscuity

Answer 13

males and females mate freely without bonds which increases genetic diversity but causes paternity confusion (chimpanzees and bonobos engage in promiscuous mating)

Question 14

Are humans monogamous

Answer 14

evidence suggests that while social monogamy is common, genetic monogamy is less strict due to extra-pair relationships. Cultural practices such as polygyny and polyandry, along with sexual dimorphism indicating a history of mild polygyny and varying mating patterns, all point to humans being “flexibly monogamous” rather than strictly monogamous