Twelve newly released photos of endangered white-winged albatrosses show them abusing each other as they mate.
Not a good sign for the 2,000-plus birds known for their love of mate-swapping and swapping partners often.
“These birds, who are at the top of the food chain, now divorce in one wing on the first day of the mating season, which has never happened before,” a National Geographic-backed research team told the New York Times on Friday.
The study also identified a gene mutation that could affect birds’ fertility.
The researchers analyzed plumage records of 176 adult and juvenile albatrosses, analyzing them with genetic-mapping tools and hoping to uncover a genetic cause for the anorexia-like behaviors.
Unlike most of their other attributes, which shine through on the glossy gray-and-brown plumage of adult birds, evidence of anorexia was not present in juvenile birds, notes the study.
Albatrosses the world over are on the plummeting edge of survival, suffering a loss of more than a third of their numbers from losses of warm-water species — like salmon and tuna — and increasing competition from oil spills from the shipping industry.
More than 90 percent of known threats to albatross populations occur from human activities.
The conservation group BirdLife International coined the term “nest abandonment” to describe a sort of unevolved coping mechanism — for which researchers now believe there may be a genetic factor.
“For each colony in the world, we found the equivalent of roughly the number of divorces the birds used to have before they started breeding,” Oren Van Thalen, a biochemist at Tel Aviv University who was part of the study, told the Times.
Van Thalen and his colleagues noted that albatrosses’ reproductive success had declined in the 30 years that the researchers studied on those populations.
“Adult albatrosses had a 25 percent higher rate of abandoning their nests during this period than they did in the 1980s, when the frequency of abandoned nests dropped by nearly 90 percent compared to 1980,” according to the paper published in Science Advances.
“Exempted colonies showed rates of abandonment of only 10 percent, compared to 40 percent during the 1980s,” they said.
“In the Pacific flyway, a group of most endangered albatrosses, the abandonment rate was 74 percent among parent-heir pairs during this period, compared to 18 percent during the 1980s,” the paper added.
Albatrosses would survive even without abandonment, of course. But the study authors found evidence of the gene mutation behind it — which could explain the females’ anorexia-like behaviors.
Dr. Ko Ping, a geneticist at Imperial College London who assisted in the study, told the Times that the mutation “requires some adaptations to have an effect.”