Divorce Rates in Albatrosses May Be Rising Due to Climate Change: Study
“Few animals seem more affectionate than black-browed albatross. These large seabirds, whose dark eyebrows shadow their eyes like mascara, are socially monogamous and often mate for life,” Science American recently noted.
But not every relationship can weather the challenges of long-distance and the stress it can cause. According to a new study, climate change may be causing “marriage” trouble in albatrosses, seabirds rather well-known for monogamy.
Divorce among albatross is the human equivalent of cheating — when part of a couple mates with another individual. There may be some hit and try at the start; “but ultimately, when they find a good match, they normally stick together for life,” BBC News noted. To put this into context: only 1% of albatrosses separate after choosing their life partner.
“Monogamy and long-term bonds are very common for them,” Francesco Ventura, a researcher at the University of Lisbon and co-author of the study, said. Monogamy also serves a practical purpose; in that, it helps build trust as the pair alternates between taking lengthy food-gathering trips and egg-incubation duties. Trust is the hallmark of their relationships too.
Rising temperatures in oceans due to man-made activities may have changed these dynamics. The research, published in the Proceedings of the Royal Society B, looked at 15,500 breeding pairs in the Falkland Islands over 15 years. As the water temperatures grew warmer, almost 8% of albatrosses split up.
This becomes the first evidence of warmer sea temperatures and environmental conditions increasing divorce rates in a wild monogamous species. “Environmentally-driven divorce may be an overlooked consequence” of climate change, researchers argued.
Related on The Swaddle:
What brings about an albatross divorce, you ask? The incompatibility is triggered when a pair fail to breed, so the female albatross in the family will leave to find new partners in the next breeding season. But in this case, researchers found the birds broke up despite having a successful mating season.
To understand the trend of these divorces, the researchers looked at two environmental factors that determine albatross’ life trajector: wind speed, and sea surface temperature. For starters, warming waters may mean less food for sea birds, who are then are traveling farther to forage food.
“Higher winds make it easier for them to soar for greater distances to gather food. Increasing sea-surface temperatures, on the other hand, limit the nutrients available to foraging albatross… As a result, albatross must travel farther and struggle more to find enough food,” Scientific American explained. In other words, the stress of less food availability may drive them to conflict. This marks strike one for what kept the relationship stable.
Moreover, due to the harsher environment, the stress hormones in albatrosses may increase which could be linked to more break-ups. To put this into perspective, climate change stress may pose very relatable challenges: the stress that comes with longer working hours and the conflicts that arise due to long-distance travel.
“Previous successful females are the ones that are most affected by this [warming],” Ventura says. “They divorced more often, when in theory they should have remained together with their previous partner.” Ventura called this the “partner blaming hypothesis”; you know, when the female albatross conflates the stress caused by environmental factors with the partner’s poor performance.
The monogamous species of albatross may not be the only ones who find their dynamic altered due to climate change. Studies have shown the extreme weather changes male dragonflies’ wing color, which reduces their mating changes — and in extension, their survival. A 2019 research also found climate change and rising temperatures are reducing mating tendencies in some birds. “The researchers found that the higher temperatures climbed, the less male little bustards performed their mating displays… Coupled with extensive habitat loss, scientists warned this temperature-driven decline could cause local or region extinctions,” Yale Environment explained.
Eventually, the current divorce trends could impact the overall population of the albatrosses too. This comes at a time when albatross numbers throughout the world are already dwindling. “If you have a situation where increasing sea-surface temperature is leading to higher divorce rates, that reduces breeding success for the population as a whole,” Ventura said.
“Ultimately, you’re sending fewer albatrosses out into the world, and that’s going to impact the population more widely.”