Birds frequently practice monogamy, and it is generally known that many seabird species pair up for life. Famous examples are the charming albatrosses and penguins, who are frequently presented in the media as the ideal marriage. However, this romantic cliche does not provide a complete picture.
According to research, up to 24% of wandering albatross chicks and up to 31% of species of penguins are raised by a male who is not their genetic father. Not quite the sweet idyll that we are told about.
Seabirds have a long lifespan; roving albatrosses have been reported to live for more than 60 years. You might assume that with their extended period of getting to know one another and their elaborate courtship dances, breakups should be uncommon. Growing data suggest that seagulls do, in fact, “divorce.”
According to our recent study, 13% of wandering albatrosses raised on the isolated Crozet Archipelago in the Indian Ocean experience divorce during their lifespan due to a lack of females and the aggressive behavior of some males.
Birds will occasionally split up to find a better partner. It is unclear how birds evaluate potential mates. But it might have to do with maturity and behavioral qualities that the birds can notice. This phenomenon, known as adaptive divorce, has previously been observed in some seabird species, including penguins.
However, in our investigation, something different took place. Contrary to some other species, wandering albatrosses did not appear to benefit from divorce in terms of increased reproduction or evolutionary advantages.
Couples in the demographic we studied were torn apart by what is known as forced divorce. This is how a bonded pair of birds is broken up by one bird, most likely the males in our study.
Display personality: This was the first study in the wild to examine the behavioral traits of these aggressive “homewrecker” males, such as aggression.
From anemones to elephants, the animal kingdom’s study of personality is thorough. We are aware that the personalities of seabirds vary depending on how successfully they reproduce and go about foraging. Characteristics like boldness, neophobia (fear of new things), and violence are used to quantify personality, which is defined as a constant individual difference in behavior.
We used two methods to gauge personality in roving albatrosses. The first method is known as a “human approach,” in which a person approaches a bird that is incubating an egg on its nest and takes note of its reaction. Both sexes can be evaluated in this way because males and females share the responsibility of incubation. The tester had to wear snow shoes to prevent sinking because the birds’ nests were on marshy ground.
Additionally, we investigated how the birds reacted to a brand-new item, in this example, Betsy the space-hopper cow. Unfortunately for Betsy, the albatrosses were all far more hostile toward her, despite the fact that personality distinctions between the individual birds persisted. Late in the season, a particularly brazen bird tore open Betsy, and she did not survive.
The albatrosses were a mix of fearless individuals who rose up and called out and shy ones who showed no reaction. Confident women were not more likely to get divorced than audacious women. Guys who were more reserved had higher divorce rates, indicating that assertive males might be driving reserved males from romantic relationships.
Rarely do ladies exist alone. Because more females pass away from being ensnared in fishing gear, the Crozet albatross population is biased toward men. The hunting tactics of males and females differ and evolve over the course of their lives. For instance, when they get older, males travel to Antarctic waters further south. Females spend their entire lives in subtropical waters and forage in locations further north.
Since we previously demonstrated that divorced wandering albatrosses do not produce additional young, females are probably not benefiting from looking for new partners. This lends credence to the idea that wandering albatross pairs do not deliberately split up. Instead, it appears that a few troublesome males are breaking up the relationships of these normally monogamous birds.
