Albatrosses: Birds known for monogamy that are breaking up due to climate change, study finds
Divorce rates among notoriously monogamous albatrosses are boosted by climate change, such as warming waters force men to travel farther for food.
This is the conclusion of a study led by researchers from the University of Lisbon, who spent 15 years studying browed albatrosses in the Falklands.
Normally, only 3.7 percent of birds split from their chosen mate — a parting of the ways that occurs in the wake of a failed attempt to breed offspring.
Still, this figure rises to eight percent at high water temperatures, with pairs breaking up even after a successful previous breeding season.
The researchers have proposed two possible explanations for how warmer sea temperatures could increase albatross divorce rates.
The first is that males — forced to hunt longer and fly farther — don’t return to their breeding grounds in time in warmer years, so the females move on.
Alternatively, harsher conditions and food scarcity can increase the levels of stress hormones in the birds, negatively evaluating even successful pairs.
In the wake of this, female albatrosses may choose to try their luck with a different mate next year, in the misguided hope that a change will make breeding easier.
Divorce rates among notoriously monogamous albatrosses are being boosted by climate change, as warming waters force men to travel further afield for food. In the photo: a breeding pair
BLACK USED ALBATROSSES
Kind: Thalassarche melanophris
Length: 31–37″ (80–95 cm)
wingspan: 79-94″ (200-240cm)
Natural Lifespan: 70 years
Range: Southern Oceans
The study was conducted by biologist Francesco Ventura of the University of Lisbon and his colleagues.
“In many socially monogamous species, divorce is a strategy used to correct for suboptimal partnerships and is determined by measurements of past breeding performance,” the researchers wrote in their paper.
“The environment affects the productivity and survival of populations, and thus indirectly divorces through changes in demographic rates.
“However, it remains poorly understood whether environmental fluctuations directly modulate the prevalence of divorce in a population.”
Since 2003, the researchers have been collecting data on the eyebrow albatross population that breeds on New Island, in the Falklands, which are estimated to number about 15,500 bird pairs.
Focusing on five separate subcolonies, the team recorded the annual encounters between breeding birds that nest in each study area, along with the identities of non-breeding birds that enter the same areas.
Individual birds were identified by marking rings placed around their feet.
The researchers also tracked the fate of each egg and chick.
The team confirmed that albatross pairs were more likely to separate in the wake of breeding failure, with the birds choosing to select new mates in the following breeding season.
In particular, female albatrosses — which tend to split up — were 5.4 times more likely to split with their mate if their eggs didn’t hatch.
However, the team also found that regardless of past breeding achievements, albatross divorce rates increased over the years with warm sea surface temperature anomalies, up to 8 percent of all breeding pairs.
“Environmentally driven divorce may therefore be an overlooked consequence of global change,” the researchers warned.
Normally, only 3.7 percent of birds split from their chosen mate — a parting of the ways that occurs in the wake of a failed attempt to breed offspring. Still, this figure rises to 8 percent when water temperatures were raised — with pairs breaking up even after a successful previous breeding season. In the photo: a breeding pair of eyebrow albatrosses
Since 2003, the researchers have been collecting data on the browed albatross population that breed on New Island, in the Falklands — home to some 15,500 bird pairs.
While albatross populations in the Falkland Islands are not currently threatened, rising temperatures could pose problems for smaller populations in other areas in the future.
Current climate changes could also affect other species that usually choose long-term mates, the researchers warned.
“We argue that examining divorce from a temporal perspective can provide critical insight into the role of the environment in divorce in other socially monogamous populations of birds and mammals,” the team concluded.
The study’s full findings were published in the journal Proceedings of the Royal Society B.
WHAT WILL CLIMATE CHANGE DO TO OUR OCEANS?
According to the National Ocean Service, climate change will contribute to ocean acidification.
This change can be attributed to higher levels of greenhouse gases created as a result of human activities.
Climate change affects the ocean in several ways.
A new study has found that methane eruptions in a region off the coast of Norway are not caused by climate change as previously believed. However, scientists warn that the human-caused effects of climate change still linger (file photo)
It can cause sea levels to rise and suffocate coral in the sea.
According to the National Ocean Service, climate change can also affect ocean currents, causing “turbid” water conditions with reduced amounts of light.
The organization has provided the following tips to reduce the amount of damage to the oceans:
- Eat sustainable seafood.
- Avoid dumping household chemicals into storm drains.
- Drive as little as possible.
- to recycle.
- Print less.
- Help with cleaning up the beach.