The ideal human romance is so formulaic, isn’t it? You meet, you fall in love, you stay together, the end. The animal kingdom is much more engaging. It has a soap opera of its own, featuring love stories that range from the strangely adorable to the utterly bizarre. From animals that mate for life to commitment-phobic creatures, animals show us that when it comes to love, there’s more than one way to form a bond.
So, forget romantic comedies and Shakespearean tragedies; here’s the real drama of relationships in the wild.
Animals that mate for life do exist. But it’s complicated
If you think your love life’s been wild — you don’t want to know what some of the animals out there are up to. From vomit-filled kisses to dung-flinging battles for literal “top seed”, animal love lives are truly some of the most bizarre things out there. Crazy mating rituals aside, a few species of animals do manage to aim for a bit of stability by forming monogamous bonds with their significant others.
But animal monogamy is not common. In fact, as per a 2019 study, the notion of “forever and always” may just come easily to individuals of a few species.
So, if you’re down on your luck and looking for examples of commitment in the world — look no further; let’s take a look at the love-crazed fanatics of the animal kingdom.
The serial monogamists: birds
When we think of monogamous animals, most of us (read: FRIENDS fans) probably picture lobsters yet lobsters aren’t actually even monogamous. With about 90% of all known species forming socially monogamous bonds, birds are the vertebrate class that reigns supreme when it comes to monogamy. Most birds that practice monogamy either do so for a singular breeding season, as a seasonal urge, or commit hard, for a whole lifetime.
So if you’re looking for animals that mate for life, birds are a good place to get started.
Love, death, and swans
Species like Mute Swans are like the high-school sweethearts of the animal kingdom. For most mute swans, monogamy is a non-negotiable.
A universal symbol of love and togetherness, these birds are one of the best-known examples of monogamy in the wild and will often spend an entire lifetime with their partners. However, in some instances, even the most committed of animals can’t seem to make it last. Even swans are susceptible to heartbreak in times of death (or worse, adultery leading to “divorce“).
In those infrequent instances when recoupling does occur, the speed of moving on is differs gender-to-gender. Males have a rougher go of it as females generally recouple quickly, often opting for younger males.
Monogamy in mute swans is not just about raising offspring; the partners also engage in synchronized swimming and mutual preening, which is thought to strengthen their bond.
This enduring relationship benefits the offspring as well. Both parents are involved in nest-building, incubating the eggs, and taking care of the young. Having two committed parents can improve the chances of survival for the young swans, known as cygnets.
The monogamous behavior of mute swans has often been romanticized in literature and art, serving as a symbol of enduring love and partnership. However, it’s important to note that the reasons for this long-term bonding are likely practical, ensuring a higher rate of survival and reproductive success.
Social monogamy in penguins
Monogamy in penguins is either a hit or a miss. Species like the Adélie and Gentoo penguins are socially monogamous. This basically means that for a single breeding season, mates pool resources and responsibilities to raise a brood of eggs.
Although mates, bonded for the season, raise chicks together; this doesn’t necessarily mean that they’re “together-together”. A lot of the time, the male penguin that raises a brood of chicks with his partner might not have even fathered all of them. This is because prior to committing to raising chicks for the season — penguin species, like the Gentoo, actually play the field quite a bit. Basically, penguin love lives? They’re together for the kids.
Some penguin species do show a tendency to find the same mate in subsequent years, provided both individuals return to the breeding ground and find each other. Studies have shown that re-pairing with the same partner can increase reproductive success, presumably because the couple doesn’t have to “learn” how to work together anew each time.
If the love lives of penguins left you a bit disillusioned; don’t fret, we’ve got just the pickup you need.
Love is in the air
- Greylag geese are birds that love love. With an average lifespan of around 20 years, the Greylag Geese spends almost all of these years with the same partner! In fact, research from 2011, illustrated that similar to humans, Greylag couples experienced observable changes in heart rate when separated from their paired partners.
- The pride of ‘Murica — Bald Eagles, mate for life yet…don’t actually spend too much time with their mates. The pair, once bonded for life, spend at most a few weeks of the year together (during breeding season). Once the job’s done and the chicks are raised, mom and dad head out on solo vacations for the rest of the year and reunite again, sometimes even preferring to use the same nest as last time to raise the next batch of chicks.
- Although technically committed for life, Albatrosses have a bit of an unconventional take on monogamy. These birds, similar to Bald Eagles, spend the breeding season and subsequently raise their chick with the same mate for their entire life. However, they do explore part-time opportunities with other birds if the opportunity presents itself. Even when Albatrosses suffer heartbreak and “divorce”, it isn’t the open nature of their relationship that causes them trouble, funnily enough, it’s the climate. Research points towards a correlation between rising sea temperature and rates of divorce in albatrosses. This indicates that as environmental conditions become more unpredictable, the subsequent constraint on resources makes staying together a tricky journey to navigate.
So many birds mate for life — it’s just not always in the way you expect it.
The cynics: mammals
In spite of the nonchalance of their arrangements, over 90% of all known avian species still engage in some form of monogamy. This number becomes all the more impressive when we consider that only less than five percent of mammalian species actually engage in monogamy. If you’re looking for animals that mate for life, mammals are probably not your best bet.
So what’s the deal with mammals and monogamy?
Turns out, it all comes down to genes. Life is a race and evolutionarily speaking, the animal that spreads their genes far and wide wins. So when it comes to mammals, animals with typically long gestation periods, adopt social structures and strategies different to that of birds and reptiles with much, much shorter gestation periods.
Think of it like this, a female mammal with a long gestation period can only invest in one litter or child for a long time whereas male mammals can in the same period of time, copulate with and thus father multiple litters or children at once. Most mammalian species, like tigers, generally follow this route yet a few species of mammals like wolves, and beavers, and a few species of primates like gibbon form the small minority of mammals that attempt to sustain some version of monogamy.
Monogamy and power in wolf packs
Wolves run in packs and within these packs, only one pair-mate, comprised of the alpha male and female, actually mate to give birth to young ones. Usually, alpha males and females are at least sexually monogamous and repeatedly mate with each other as a show of power and dominance within the group.
Apart from mating to stabilize pack dynamics, wolves also just stick together because they’re good at it. Research indicates that the longer a pair of wolves stick together, the better their chances of raising their young ones. Essentially, each breeding season they spend together ends up being practice for the next one; increased sociability, efficiency, as well as age, and experience all positively contribute to a higher probability of raising their young into adults.
A dam true love: Beavers
Eurasian Beavers might just be a rarity amongst mammals — they’re a striking example of an animal that mates for life. Not only do they engage in monogamy socially, but individuals within populations have also been observed to be sexually monogamous as well!
A study, conducted by researchers from Charles University in Prague, Czech Republic, aimed to study the genetic makeup of Eurasian Beaver colonies in Russia. They found that in every colony they studied, all of the litter were fathered by the same male — the male of the pair-bond.
Although monogamous, Eurasian Beavers err more on the side of ease of convenience as opposed to a sense of love. You see, Eurasian Beavers, unlike their American counterparts, are highly aggressive and territorial. Additionally, they almost exclusively feed on tree bark and hence need a lot of bark to meet their nutritional intake. In essence, it makes more sense for these guys to team up for the long haul. Together the pair guard their territories, collect bark to their hearts’ contents, and raise their babies.
A love for music (and each other): Gibbons
Gibbons have one of the cutest courting rituals out there — they sing and harmonize with each other. Each gibbon has a distinct mating call and when seeking out mates, gibbons sing to one another. Eventually, upon zeroing in on their mate of choice, each pair is bonded by “their song”. This song is a duet that which both the male and female sing together to communicate with one another. To make things more romantic, the song isn’t just a random tune; its their individual mating calls combined!
Gibbon pairs burst into their song in everyday moments of their lives, like when they’re grooming each other or need to find one another in times of separation.
Monogamous mammals: not a myth
Still, while the vast majority of mammals don’t mate for life, some do.
- California Mice: These tiny rodents might have figured out the trick to monogamy (even in the face of temptations!): live short and commit hard. They live for a year or two and reach sexual maturity at around 11 weeks.
- Prairie Voles: Similar to California Mice, Prairie Voles are monogamous rodents. Both California Mice and Prairie Voles, show not just tendencies of social monogamy but possess incredibly strong pair-bonds with their mate of choice. In Prairie Voles in particular, research indicates that if one mate in the pair-bond dies, over 80% of the time, the remaining mate chooses to forgo forming another pair-bond. In an article published on NPR, Larry Young, a researcher from the Primate Research Center at Emory University commented that although the remaining mate may choose to mate with another individual; they never actually end up bonding with them, at least not in the way they did with their chosen first mate.
“That’s what we’re really studying here; we’re studying the bond…only about 3 percent of mammals exhibit this kind of monogamy,” opined Young in the same NPR article.
A short story: Reptilian love
Reptiles don’t really mate for life that often. Most reptiles are asocial. Even when it comes to shacking up for the breeding season, they’d rather achieve reproductive success and be done with it.
Parental care is uncommon in reptiles. In a few species, post-mating, females invest time and effort to build nests for their eggs and some even attempt to guard these nests. Males, on the other hand, are especially aloof and don’t stick around to dispense parental care to their young ones.
However, it’s not all gloom and doom in the reptilian way of life. A few species have been documented to do more than the “bare-minimum”, as us human folk would say.
S-kinky love: Monogamy in Shingleback Skinks
Shingleback skinks are anomalies amongst reptiles. Similar to birds like Bald Eagles, Shingleback Skinks also spend most of the year apart but reconnect with the same mate every year for the breeding season. Before committing to a partner for life, these reptiles have an extended “get-to-know-ya” period of courtship filled with a healthy amount of lickin’, touchin’, and lovin’.
See you later (specifically: every breeding season) aligator!
Although we don’t spend a lot of time contemplating the nitty-gritty realities of reptilian love; it still is surprising to know that alligators may just be monogamous. A study conducted by the Savannah River Ecology Laboratory revealed that in a dense population of alligators in the Rockefeller Wildlife Refuge, Louisiana, around 70 percent of re-trapped females exhibited evidence of mate fidelity.
According to Stacey Lance, one of the investigators on the study, the results were especially surprising considering the open and dense nature of the population in question.
“To actually find that 70 percent of our re-trapped females showed mate fidelity was really incredible. I don’t think any of us expected that the same pair of alligators that bred together in 1997 would still be breeding together in 2005 and may still be producing nests together to this day, “said Lance in an article published on LiveScience.
Creepy committed crawlies: Insects
Insect sex is wild. From sex-reversed genitals to removable genitals to exploding genitals; it’s hard keeping up with the seedy underbelly of insect copulation yet there are a few “tame” insects out there that crazy mating rituals aside, settle down with the same partner in the long run (exploding male drone bees and suicidal male ants notwithstanding).
Monogamy in termites
Unlike ants and bees, termites don’t all flock to worship a single queen; rather — it’s a king-and-queen situation. Similar to ants, virgin termites embark on the nuptial flight — an annual ritual that forges life-long relationships with a single mate with whom they establish new colonies.
Fun fact, in hard times, male termites shack up with each other when they can’t find females to settle down with. In these homosexual relationships, male termites build nests together and cease looking for females altogether. However, if the homosexual pair comes across a heterosexual colony of termites, the males engage in “conflict” with the heterosexual male. One of these males eventually kills the heterosexual male to mate with his widowed queen; thus dissolving the homosexual bond.
Cannibalism (and monogamy) in insects that mate for life
This is where it gets particularly terrifying. You know how we mentioned that some animals mate for life but not in the way you’d expect? Well…
Taiwanese cockroaches mate for life — in a particularly gruesome way. The roaches, having found each other, retreat to a life of seclusion. The roaches don’t just share their nest with each other — they also share cannibalistic tendencies. Research conducted by Haruka Osaki, a Japanese biologist from Kyushu University, Japan, revealed that these insects practiced “mutual cannibalism” and took turns munching on each others wings.
Although technically gruesome, in the cutthroat world of insect sex, mutual cannibalism might just be one of the more romantic tales out there.
Also, in some species (like the praying mantis), the female kills and eats the male. Is that mating for life? For the male, it sort of is, but you probably wouldn’t consider it that romantic.
Animals that mate for life — why do they do it?
Although there’s no clear-cut answer — scientists have long pondered the implications of “exclusivity” in nature. To figure out the same, researchers from the University of Texas at Austin studied Prairie Voles — one of the few species that comprise the low minority of mammals that mate for life.
They found that it all came down to DNA. Differences in the DNA of male Prairie Vole brains revealed that each vole may have individualistic tendencies and preferences for forming monogamous relations. An interesting tidbit of the study revealed that natural selection did not actually favor an increasing tendency toward monogamy. Rather, on a genetic level, there seemed to be a co-existence of both traits (traits that favored monogamy as well as traits that favored non-monogamy).
Ecologically, this was backed up by evidence from the field. In the wild, voles that stray from their mates aren’t more successful voles that stay with their mates, and vice-versa.
According to Steven Phelps, the principal investigator of the study, when it comes to social behavior in animals, there may not be a normal brain to look to.
“This brain variation isn’t just there by chance. It isn’t random… it’s actually something that selection has kept around for a very long time. When it comes to social behavior, maybe there isn’t a normal brain,” said Phelps in a press release.
