11 Animals That Mate for Life

Gibbons

Gibbons are the nearest relatives to humans that mate for life. They form extremely strong pair bonds and exhibit low sexual dimorphism, which means that males and females of the species are of roughly equal size, a testament to the fact that both sexes are on relatively equal footing.

The coupled male and female will spend time grooming each other and (literally) hanging out together in the trees. Their connection is reinforced by the time spent grooming. But these unions are not as straightforward as they seem. With mates occasionally philandering, and even sometimes dumping a mate, the gibbon mating culture has started to look a little less idyllic.

Swans

Swans form monogamous pair bonds that last for many years, and in some cases, these bonds can last for life. Their loyalty to their mates is so storied that the image of two swans swimming with their necks entwined in the shape of a heart has become a nearly universal symbol of love.

One species, the mute swan, primarily mates for life, except in certain circumstances. If either the male or female mute swan dies, the remaining partner typically finds a new mate. If the male mute swan mates with an older female, he joins her territory, while if he mates with a younger swan, she joins his. Female mute swans usually find a new mate quickly, and most often it's a younger male.

Why do so many birds mate for life? It isn't as romantic as it first appears, though. Considering the time needed to migrate, establish territories, incubate, and raise young, spending extra time to attract a mate would minimize reproductive time.

Black Vultures

Graceful necks and heart-shaped cuddling are not a prerequisite to a faithful relationship. In fact, black vulture society makes sure of that. They have been known to attack other vultures that are caught philandering.

Researchers looked at genetic evidence from DNA fingerprinting to study the black vulture's monogamy. A study published in the journal Behavioral Ecology found that bonded pairs of black vultures stick together year-round. They also share the responsibilities of incubating and feeding their young equally, taking turns sitting on the eggs. Couples that parent together, stay together.

French Angelfish

You're unlikely to ever find a French angelfish alone. These creatures live, travel, and even hunt in pairs. The fish form monogamous bonds that often last as long as both individuals are alive. In fact, they act as a team to vigorously defend their territory against neighboring pairs, particularly during spawning season.

Researchers have also observed pairs of these patterned fish traveling to the water’s surface to release their eggs and sperm together.

Wolves

Often portrayed as tricksters and con artists in popular folklore, wolves have a family life that is more loyal than rakish. Normally, packs consist of a male, female, and their offspring, essentially making wolf packs akin to a nuclear family. The older offspring even help take care of their younger siblings. Alpha males, however, have a tendency to "cheat" on their partners.

Occasionally, a lone wolf will be welcomed into a pack. A pack can range from just three or four wolves to as many as 20, depending on the food supply in the area.

Albatrosses

An albatross may fly great distances over the oceans, but despite its extensive travels, this bird will always return to the same place—and the same partner—when it's time to breed. Pair bonds between males and females form over several years and will last for a lifetime, cemented through the use of goofy but affectionate ritual dances. In fact, the birds will court each other for years using those dances in order to pick the perfect partner. An albatross only lays one egg each year, so it's important that it chooses the best partner with whom to raise its limited number of chicks.

It's not quite so perfect as it sounds, however. According to the Ocean Conservancy, the albatross may be socially monogamous, but sometimes engages in "extra-pair copulation": "Albatross will mate with another bird that is not their life partner all while maintaining that life bond with said partner. While to some people this may seem nefarious, it isn’t uncommon in the natural world."

Termites

In an ant colony, a queen mates once with the male(s), stores the gametes for life, and the male ants die shortly after mating. In contrast, several species of termites can form lifelong pair bonds between a female "queen" and a single male "king" who literally give birth to their entire kingdom.

Termites tend to stay with the same mates for a long time. They might stick together for as long as 20 years in some species. If termites do break up, things can get ugly, says researcher Janet Shellman-Reeve of Cornell University. She found that relationship splits are often accompanied by physical violence. Termites may chew off each others' antennae, for example.

Prairie Voles

Although most rodents have a reputation for promiscuity, prairie voles break the trend, generally forming monogamous pair bonds that occasionally last a lifetime. In fact, the prairie vole is typically cited as an animal model for monogamy in humans. They huddle and groom each other, share nesting and pup-raising responsibilities, and generally show a high level of supportive behavior. When a partner dies, the other displays a form of grief.

If a male vole shows even the slightest hint that he's not going to stick around once babies are born, the female will grab him by the scruff of the neck. That's rarely necessary, however, because after all, the word "vole" is an anagram of the word "love."

Turtle Doves

There's a reason that turtle doves come in pairs in the song "The Twelve Days of Christmas."

Turtle doves are also known as mourning doves or rain doves. A male courts a female by flying to her noisily, with his wings making a distinct whistling sound. He then puffs out his chest, bobs his head repeatedly, and calls to her. When the pair starts bobbing their heads in unison, they are smitten for life.

Sandhill Cranes

Sandhill cranes find their lifelong mate on breeding grounds during mating season. The single cranes perform dances and make loud calls to find their partner. While the mating dance is most common during the breeding season, the cranes still find time to dance, even after they've found their lifelong partner.

After mating, the male and female cranes care for their nest together while the male stands guard. Once the eggs are hatched, sandhill cranes remain a family unit until the juvenile cranes are ready to venture off and start their own families in about 10 months. The couples stay together for years, raising one brood each year.

Bald Eagles

They are the national emblem of the United States, and when it comes to maintaining relationships, bald eagles soar much higher than the country they symbolize. Bald eagles typically mate for life, except in the event of their partner's death or impotency.

Bald eagles will spend winters and migrations alone, but both partners return to the same nest year after year. Each time, they add to their "home," fluffing their nest and making it larger and stronger.