Define polyandry and discuss its occurrence in mammals.

• A. A mating system where a female mates with multiple males; relatively rare in mammals.
• B. A mating system where a male mates with multiple females.
• C. A system where one male mates with one female.
• D. A mating system where groups share a mate.

Answer: (A)

Polyandry is a mating system in which a female mates with multiple males within a breeding cycle, potentially producing offspring sired by several different fathers. In mammals, this pattern is relatively rare compared with systems where a single male pairs with multiple females or where mating is more promiscuous without lasting bonds. When it does occur, it often arises in social contexts like cooperative breeding or multi-male groups, and it can help a female gain genetic diversity for her offspring, increase access to resources or protection from different males, or enhance paternity confusion to influence male parental investment. The idea is that the female is not limited to a single mate, which distinguishes this pattern from other systems. The other options describe different mating arrangements: one male with many females is polygyny; one male with one female is monogamy; a group sharing a mate points to other social structures that aren’t defined by a female mating with multiple males.