A.   The number of males who are available for mating

B.   The number of gametes females can produce

C.   Food availability

D.   All of these statements are correct

A.   All of these statements are correct

B.   Gaining more access to resources by cooperating with other females

C.   Gaining more access to resources by being successful in competition with other females

D.   Finding the optimal amount of care to invest in offspring

A.   Males invest more in care of offspring than females do

B.   Allomaternal care is more likely

C.   The more females invest in the care of their offspring, the less time and resources they have to devote to future offspring

A.   favors traits that make individuals more attractive to the opposite sex

B.   favors traits that make individuals more successful in competition for access to mates

C.   Both of these responses are correct

A.   Tail length

B.   Reproductive success

C.   How long a monogamous pair bond lasts

A.   In one-male/multi-female groups

B.   In species that have enduring pair bonds

C.   False; males never invest in offspring

A.   In polyandrous groups

B.   In one-male/multi-female groups

C.   In multi-male/multi-female groups

A.   Humans are present

B.   Variation in reproductive success is the highest for males

C.   Monogamy is common

A.   All of these statements are correct

B.   Ends when offspring are weaned

C.   Temporary

D.   Occurs because nursing requires an enormous amount of calories

A.   When a male increases in rank

B.   During the rainy season

C.   When a new female enters a group