Problem 3 - Campbell Biology

Question

Female spotted sandpipers aggressively court males and, after mating, leave the clutch of young for the male to incubate. This sequence may be repeated several times with different males until no available males remain, forcing the female to incubate her last clutch. Which of the following terms best describes this behavior? (A) polygyny (B) polyandry (C) promiscuity (D) certainty of paternity

Step-by-Step Solution

Answer

Polyandry

Step 1: Understand the Behavior

The behavior described involves a female courting multiple males and leaving each clutch of young for the males to incubate.

Step 2: Define Key Terms

Polygyny is when one male mates with multiple females. Polyandry is when one female mates with multiple males. Promiscuity is when individuals mate with multiple partners without forming a stable pair bond. Certainty of paternity refers to the assurance a male has regarding his offspring.

Step 3: Match the Behavior to a Term

The behavior described matches one female mating with multiple males, which fits the definition of polyandry.

Step 4: Select the Best Answer

Based on the definitions, the best term that describes the behavior is polyandry.

Key Concepts

mating systems

Mating systems refer to the way animal species structure their reproductive relationships. These systems can vary widely among species. In polyandry, one female mates with multiple males. This is seen in certain bird species like the spotted sandpipers. Conversely, polygyny involves one male mating with several females. Promiscuity, another system, involves all individuals mating with multiple partners without forming lasting bonds. These strategies increase genetic diversity and can influence evolutionary direction.

animal behavior

Animal behavior encompasses all ways animals interact with each other and their environment. It includes courtship, mating, and parental care. In the case of polyandrous species like spotted sandpipers, females aggressively court males, which is part of their strategy to maximize reproductive success. Understanding these behaviors helps in studying species survival and adaptation mechanisms.
Behavioral studies reveal that environment can shape these adaptations. For instance, where males contribute to parental care, polyandry can be advantageous.

reproductive strategies

Reproductive strategies are the methods through which animals ensure their genes are passed on to the next generation. Polyandry, illustrated in spotted sandpipers, is one such strategy where females diversify their mating partners to ensure genetic variability and receive help in rearing offspring. This contrasts with species that practice polygyny or monogamy, where reproductive roles and investments differ greatly.
These strategies reflect evolutionary answers to ecological challenges such as predation, resource distribution, and mating opportunities.

certainty of paternity

Certainty of paternity is crucial in understanding animal mating systems. It refers to the confidence a male has that he is the genetic father of the offspring he is investing in. In polygynous systems, males often employ behaviors to ensure paternity, like mate guarding. In polyandrous systems, such as with spotted sandpipers, this certainty can be lower, but males may still invest in offspring due to the high competition for mates.
This concept is tied to evolutionary incentives where males maximize reproductive success by ensuring their paternal investment translates into their genetic legacy.