As climate change roars, an albatross returns home to find his lover in the wings of another.
Albatrosses have the largest wingspan on modern Earth and the lowest divorce rates. Birds couple up for life, all 70 years of it, regularly practising long-distance to come home and rest their heads lovingly on the breast of their partner. Of all the couples, only four percent break up (technically called “divorce”), a staggering number compared to the 40% in humans.
But this is all changing.
Monogamy
Monogamy may not be what it seems in the animal kingdom. Human-centric conservatism assumes the practice to be sexual monogamy (otherwise known as genetic monogamy), meaning a pair of animals that have eyes exclusively for one another. They do not, under any circumstance, mate with another individual. But, the more common form of monogamy in the animal kingdom is called social monogamy, meaning the male and female mate, raise young together and spend time together – but they also mate with others outside of the pair. For humans, we would call this an open relationship.
Monogamy isn’t simply romantic. It’s functional. Just like flight, beaks and vocal cords, monogamy confers certain evolutionary advantages. For their young to survive, bird parents must build a nest, incubate eggs, forage for food and fight off predators, sometimes with simultaneous needs. The parental time investment to raise chicks is too large for one individual. But, if the job of parent was reliably shared between two individuals, that significantly increases the chances of offspring survival.
Divorce
Just like in humans, monogamous animals are prone to breaking up, a process that scientists have termed divorce. The logic behind divorce is a simple question: if I stay with you, will you successfully help me raise offspring and pass on my genes? If you’re infertile, goodbye.
Divorce evolved alongside of monogamy, and for good measure. Where monogamy can be a great way to increase your chances of passing on your genes, it would be devastating if you pair with the wrong indivisual. It needs an opt-out system for the benefits of monogamy to shine.
Different species have different divorce rates, i.e., the number of couples per 100 that break up. Broadly speaking, species that live in inherently turbulent environmental conditions or areas with high predation will have increased divorce rates. The greater the need to have a capable suitor, the more likely the animals will break up in search of a partner that can better provide. Whereas, if the environmental and predation conditions are calm and reliable, it doesn’t affect offspring survival greatly if the partner is slightly less capable of, for example, finding food.
Climate Change
A team of scientists set-up cameras on the Falkland Islands which are strung along the Argentinian coast to watch albatross relationships. As the years went on, a drama unfurled. Albatrosses were breaking up at unprecedented rates.
Correlating the heartbreaks with external factors, scientists found a link between sea surface temperature and divorce. In years with sea surface temperatures differing significantly from the 30-year average, more albatrosses’ hearts were broken.
It comes back to the question, “If I stay with you, will you successfully help me pass on my genes?”. Increases in sea temperature make it difficult for organisms at the bottom of the food chain, like phytoplankton, to grow. With less phytoplankton available, there’s less food for fish, and, therefore, less fish for animals further up the food chain, like seabirds.
In years when food is harder to find, albatorsses seeking food come up against new challenges. They may become injured or ill during their arduous search, may return home with less or return home late. All of which cause issues in a marital agreement. An injured partner is not able to deliver to the best of their abilities on their marital agreement to help raise young. Partners returning with less food may come across as lazy or incapable. And albatrosses waiting for their lover to return home, may assume their lover has died or give up waiting and find a new mate that has already returned with plenty of food.
Why is this important?
Aside from the heart-breaking notion of Earth’s most loved-up species losing their passion for commitment, the increased break-ups may affect the entire population’s survival.
Newformed couples are less successful at raising chicks due to an inexperience with each other. Albatrosses are already listed as critically endangered, and with more new couples forming, we may see a decrease in the survival rate of chicks.
