Monogamy in animals
Many animals that maintain elaborate nests or dens also tend to favor monogamous pairings since both parents are needed to maintain the shelter. The beaver is a good example of an animal that forms strong family bonds to maintain their dens. The adage that the guy and gal fall in love and live happily ever after is rare in the animal kingdom -- unless you are talking about birds. Scientists estimate that only 3 percent to 5 percent of mammals are monogamous, choosing a single mate and having both of the parents raise the offspring, while nearly 90 percent of bird species exhibit this trait. Scientific studies of animal behavior state that monogamy is a preferred strategy when an animal has defenseless young and offspring have a long childhood.
Monogamy is also a standard trait in animals that require both parents to protect the young and provide food. In birds, this is a desirable trait. Once the eggs are laid, one parent needs to incubate them while the other needs to search for food.
Many animals that maintain elaborate nests or dens also tend to favor monogamous pairings since both parents are needed to maintain the shelter. The beaver is a good example of an animal that forms strong family bonds to maintain their dens. Monogamy is also a preferred strategy when the cost of acquiring a mate is high. That is why many small mammals, such as mice and voles, tend to have monogamous relationships. The more time spent away from the burrow is yet another chance they will be eaten by a predator.
Very mobile animals, such as birds, that have easy access to potential mates also tend to be monogamous whereas very solitary animals, or animals that have large home ranges, tend to be less choosy and are polygamous. With monogamous animals, the male and female tend to be the same size and polygamous animals tend to display more dimorphism with the male (sometimes the female) being one to two times larger than the female. In some species, such as bear, the male is chased away from the den by the mother, usually in response to food scarcity.
Today, most societies recognize marriage and both parents raise their children. This lifestyle tends to favor monogamy. Nonetheless, beavers, foxes, wolves, otters, pine voles and most birds are considered more monogamous than humans.
Article by FCFCDB
Nature Notes for 2/10/2013