Humans are one of the only mammals that stay together through long periods of time, sometimes whole lifetimes. I wanted to look at which other mammals practice monogamy and how it benefits them.
There are only 3-5% of all species of mammals that are monogamous. These include the gray wolf, some species of bats, foxes, beavers, and prairie voles.
If you want to know what types of monogamy there are and why they choose this lifestyle, please read on.
What Is Monogamy?
The zoological definition of monogamy is ‘the habit of having only one mate.’
In mammals, monogamy is defined as the mating couple remaining together through several breeding seasons. This may not be a lifetime relationship but does cover a large portion of their lifespan. If one of the pair dies, the one remaining may mate with a new individual.
For mammals that do not have long term relationships, monogamy can be defined as mating for the breeding season, with the male staying with the female after mating and during the rearing of offspring.
What are the Different Types of Monogamy?
There are two types of monogamy in the animal kingdom. These are genetic monogamy and social monogamy.
In social monogamy, male and female mammals cohabit for the sole purpose of increasing their survival chances and the survival of their offspring. The pair live together, co-operating in their search for food and shelter.
They also take care of their young ones together. The two animals both take part in paternal care through feeding, grooming, carrying, and defending the offspring.
Social monogamy does not guarantee sexual faithfulness between male and female partners. In most cases, the two individuals will stay together but will mate with others. However, conflicts may arise as a result of infidelity.
Genetic monogamy is the opposite of a social monogamous relationship. In a genetic monogamous relationship, the male and female do stay faithful to each other. Once they find their partner, they will stay together, mating for life.
Although some mammals are monogamous, it has been estimated that only about 3-5% of mammals practice monogamy.
There are also instances in nature where the male guards the female to make sure no other individual breaks this bond. This protection ensures that the female does not mate with any other individuals, although this may not qualify as monogamy.
However, it does explain why some species stay together for at least as long as the gestation period.
Why do Some Species of Mammal Stay Monogamous?
Many mammals invest a huge amount of time and energy into raising their young. Many males will not raise offspring from another male, so they will stay faithful to their partners, ensuring that their chosen female will birth only his offspring.
Which species of mammals are monogamous?
Gray wolves are known to form alpha couples that stay together for life. A gray wolf pup is already mature and considered an adult at the age of 2. They leave the pack searching for a new life, new territory, and finding a partner. Wolves are highly social and live in packs. A pack consists of an alpha male and his female partner.
In gray wolves, only the alpha male and female mate, producing offspring to grow the pack. The alpha male is in charge of the pack and decides the breadth of their hunting grounds.
They also lead the pack to new destinations. The dominant pair produce a litter of pups every year. A lone wolf in the wild is most likely looking for a partner.
The California mice are a species of rodents that originated in California and Mexico. These little creatures form pairs once they reach sexual maturity. The bonded pairs live together, mating for life.
Both males and females tend to be territorial and work together to defend their nest. The males are more aggressive towards any other males. This behavior is a way of scaring off competition to the female and can also be seen as a way of showing dominance.
The California mice depict both types of monogamy, social and sexual. This species of mice cannot mate with any unfamiliar individual.
They only mate with their partners, and once the female gets pregnant, she gives birth to a litter of pups. The litter consists typically of two pups, but the bonded pair can produce up to 6 litters in a single year.
The male actively takes care of the young ones, with the male doing as much work in rearing the pups as the female.
Monogamous relationships are often a rare occurrence for mammals in the wild. Most male mammals will mate, then leave the female to take care of the offspring independently. Prairie voles have proven otherwise by being entirely monogamous and loyal to each other.
Prairie voles are thought to be genetically programmed to have long-term mating partners. After finding their partners, the male and females form a strong bond. The male first courts the female. Soon after, she will go into estrus and then mate.
According to some studies conducted, the hormones oxytocin and vasopressin induce the bonding in the prairie voles. When a prairie vole gets a partner and mates, the vasopressin hormone is released.
This hormone activates the receptors in specific parts of the brain that evoke feelings of pleasure or reward. The other hormone, oxytocin, is believed to foster social bonds, maternal bonding, and childbirth.
The monogamous prairie voles have a higher level of receptors for vasopressin and oxytocin hormones. Once the pair mates, their brains are channeled into associating pleasure and the reward of mating only with a particular partner. This is the reason that prairie voles develop such strong, lifelong bonds.
The male prairie vole stays around throughout the pregnancy and is actively involved in parenting once the young are born.
Beavers are another species of mammals that spend their life with only one partner. When they are not busy restructuring and engineering the landscape, beavers are looking for their long-term mate.
Beavers live in colonies that are created by a monogamous male and female. Offspring the couple produces adds to the colony. A colony typically consists of a monogamous couple, young babies, and older kits born the previous year.
The young kits are ready to leave the colony upwards from two years old. It is at this time that they will look to find their monogamous mate.
Beavers will pair but are not entirely faithful to their mates. Once in a while, they will mate with other individuals. If a death occurs and a beaver partner dies, the living beaver will seek out a new mate.
Sea otters are considered one of the most romantic mammals because they are often seen holding hands. They hold hands so that they don’t drift apart or lose each other, but it can also be interpreted as a strong social bond.
Aside from being quite social creatures, sea otters partner with one other mate for life. The monogamous couple forms a family group consisting of them and their offspring.
They do everything together, including traveling, playing, and hunting. While many species of monogamous mammals live together, sea otters have separate male and female territories.
Otters mate every year. The male otter approaches the female and shows interest. The female will then give consent by playing and rolling around with her partner. The male might bite the nose of a female to portray his interests in courtship.
Similar to the gray wolves, the gray fox is monogamous and mates with one partner its entire life. The monogamous pairs breed once every year during the breeding season.
Gray foxes are quite different from other species because they do not associate with their mates unless it is the breeding season or raising newborn kits. At times other than these, the adult foxes are solitary, preferring to stay alone.
After a female gray fox gives birth, its partner will help raise the kits. The male will also groom them whilst protecting them from predators. While the female is nursing, the male partner heads out and forages for food. Once the young ones are old enough to leave the den, the family group then disperses.
Monogamy is not a popular lifestyle for mammals, but coyotes are a species that seems to enjoy having only one mating partner. Coyotes remain faithful to their mates even when the population is high.
Males stay by the side of their partners, playing an active role in parenting the pups. A coyote couple together establishes its territory, working to defend it. They help each other build their den or find a suitable place where the pups will be born.
Coyotes are very affectionate towards each other. When the female is pregnant, the male mate goes hunting and brings back food. After birth, both parents protect and groom the pups.
The red fox practices social monogamy. There is a bonding between the males and females, but it only lasts as long as the breeding season. Furthermore, red foxes are not committed to their partners. A male dog can mate with several other estrous females, and a female red fox might copulate with several males. Both will stay around each other to help protect and raise the kits.
Monogamy is rare in mammals, and this is not an exhaustive list of species. This does, however, give an insight into the types of monogamy that mammals experience.