ThirstyFish

White-crowned Sparrows are larger sparrows native only to North America. They generally forage on the ground and eat seeds, plant parts and insects. They are monogamous birds; they pair for life.

About 15 percent of mammalian species and 90 percent of birds are believed to be socially monogamous (pairs share the same social arrangement). However, when it comes to sexual monogamy numbers change drastically. Only 3 percent of mammalian species and only about 10 percent of birds pairs actually have exclusive sexual relationships.

In humans, sexual monogamy differs across cultures and across genders. Since studies of monogamy are based on surveys, and individuals in some cultures are reluctant to discuss their sexuality, it is difficult to acquire accurate numbers. In the United States studies report that somewhere between 10-25 percent of women and 15-43 percent of men engage in extramarital sex.

Genetic monogamy is defined as two partners having offspring with each other. In humans, rates of extrapair paternity (non-paternity) have not been extensively studied. Currently non-paternity rates in different societies are estimated to be between 1 percent to over 50 percent.