Love, mate choice, and sex are topics that have an enduring appeal among humans and even among birds too, says the University of New England’s Emeritus Professor in Animal Behavior Gisela Kaplan.
The strategies for bird mate choice
Kaplan said that choosing the right mate is the driver of birds’ evolution and it affects the success of their offspring and the survival of the species as a whole. For years, research has focused on studying birds and their sexual selection, wherein males display extra bright patterns or feathers and perform a special dance or song.
Seasonal flings and single mothers
Bowerbirds, which make up the bird family Ptilonorhynchidae, are renowned for their unique courtship behavior. In their attempt to attract a mate, bowerbirds build a structure and decorate it with sticks and other brightly colored objects. Females then choose the best mate among them, but male bowerbirds do not stick around after mating. The females are left alone to raise their brood, just like seasonal flings between two people and without the expectations of a formal romantic relationship. Kaplan added that such a kind of reproductive strategy applies only to a small proportion of the birds around the world.
A tiny percentage of songbirds are also considered “lovers for a season.” This means that the males and females raise their brood together for a season and then they go their separate ways. Studies show that these birds do not form real partnerships are only in the market for reproduction.
Globally, more than 90% of the birds are joint parenting, which means that they stick together to raise their offspring just like humans do. They form partnerships for more than just one season and even a lifetime.
This astonishing figure of birds that are into long-term affairs has no equal among other animals, even among mammals. Their secret to relationship success is lifelong attachment.
Forming lasting relationships
Just like how some humans choose a partner with similar traits, backgrounds, and lifestyles, birds are also into the idea of assortative mating. The Emeritus Professor details that the common native birds that form lifelong bonds include the cockatoos, drongos, and butcherbirds. These native birds are monomorphic, which means that the differences between the sexes are small or non-existent at all. Both females and males may look the same in plumage and size and both may build nests, sing, and provide equally for their offspring.
How, then, do they choose their mate if not by dance, plumage, song, or color difference? Some studies suggest that these birds choose their partner based on personality. Many aviculturists and bird owners attest that birds have individual personalities too, just like humans. For instance, they may be tolerant, fearful, curious, sociable, confident, aggressive, submissive, or gentle.
No research has yet conclusively established though which of these bird personalities are mutually attractive. So far, what was established are familiarity or similarities instead of opposites that attract the other sex.
In a 2009 study titled "The Use of Ratings and Direct Behavioural Observation to Measure Temperament Traits in Cockatiels (Nymphicus hollandicus)", authors from the University of California Department of Animal Science show how cockatiel breeders are now using personality assessments in birds the same way it is used for show dogs. There is scientific and practical proof to support such an approach, Kaplan opined. In the breeding context, seemingly incompatible birds may be forced together and they may not interact with each other. As a result, they are unlikely to reproduce.
A study on Gouldian finches found that mismatched birds have elevated levels of stress hormones after several weeks and this delayed the birds’ egg-laying. The same thing applies to humans.
Market research company Harris Interactive conducted a study in 2018 as commissioned by online dating platform eharmony. It found that stress from work (35%) is the key problem that negatively impacts relationships. Other things that have a negative impact on human relationships are being too tired for sex (33%), low libido/sex drive (28%), arguments about money (27%), one of the partner is a morning person, the other is all about the evening (20%), long term health problems (18%), short term health problems (16%), and arguments about children (12%).
Birds in love produce more babies
Meanwhile, another study published in the journal PLoS Biology showed that birds who freely choose their mates produce 37% more offspring compared to those paired up by researchers in their avian arranged marriage. Embryo mortality was likewise dependent on the compatibility of the genetic parents and chick mortality was dependent on the behavioral compatibility of the foster parents.
Forming friendships and not just sex
Kaplan said that bird bonds are not initially or always about reproduction. The majority of cockatoos may even take five to seven years before they mature sexually. White-winged choughs, apostlebirds, and magpies cannot seriously think of reproducing until they reach five or six years old. So, at the start, they form friendships. Some of these birds are childhood sweethearts before they reproduce.
Then, there are those socially monogamous birds, like the parrots and cockatoos, that pay close attention to each other. They reaffirm their bonds by flying together, roosting, preening, or by searching for water and food together. Even the not so cuddly songbirds, including corvids or magpies, form long0term partnerships and roost, feed, and fly closely together.
Pairing up for life
The species of birds that pair up for life or devote most of their time raising their brood generally are also the most intelligent. This was proven when researchers measured their brain mass relative to their respective bodyweight. These species also tend to live longer, some times four times longer, compared to the same birds the same weight range living in the northern hemisphere.
According to statistics provided by Pew and Research Center, although marriage is not in their top priority, most Americans consider it an important goal. Among the married people surveyed, 93% say love is a “very important” reason to get married; 84% of unmarried people believe the same thing. However, love can only go so far as 59% of married people believe having children is also very important to marry; 44% of unmarried people agree. The majority (81%) of married people believe companionship is important for making a lifelong commitment (87%).
It just goes to show that long-term bonds and cooperation is good for humans as it is for the bird species.