Final answer:
In monogamous systems, mate choice and parental care can be explained through theories such as the mate-guarding, male-assistance, and female-enforcement hypotheses. Some bird populations also exhibit parental care from both parents.
Step-by-step explanation:
In monogamous systems, one male and one female are paired for at least one breeding season. Several explanations for this type of mating system have been proposed:
- The mate-guarding hypothesis suggests that males stay with the female to prevent other males from mating with her.
- The male-assistance hypothesis proposes that males that help guard and rear their young will have more and healthier offspring.
- The female-enforcement hypothesis states that the female ensures that the male does not have other offspring that might compete with her own.
In terms of parental care, in some bird populations, both parents provide care for the young, in addition to the female's care. This can contribute to the survival and well-being of the offspring.