Migratory Flamingos Age Differently From Resident Ones, Offering a New Clue About Getting Old
A new study of the pink birds in France finds that aging sets in later for flamingos that migrate, though they face higher mortality in early adulthood
/https://tf-cmsv2-smithsonianmag-media.s3.amazonaws.com/accounts/headshot/SarahKuta.png)
:focal(2304x1733:2305x1734)/https://tf-cmsv2-smithsonianmag-media.s3.amazonaws.com/filer_public/4e/71/4e7128e0-9d5b-48f7-a74a-0121f3ad1e5d/flamants-roses-poussins-colonie-fangassiercharlotte-peerot_tdv.jpg)
Greater flamingos are eye-catching pink birds with long, slender necks and stilt-like legs. Striking appearance aside, these animals also have relatively long lifespans, with many wild individuals surviving to at least 40 years old.
But not all greater flamingos (Phoenicopterus roseus) age at the same rate, new research suggests. Birds that choose to migrate each year tend to age more slowly than the ones that stay put, although they face a greater risk of mortality earlier in life, according to a new paper published August 25 in the journal PNAS. Studying these differences in flamingos might one day help researchers unlock the secrets of aging in other species, including humans.
Scientists have long been curious about the process of biological aging—and, more specifically, why some species seem to decline faster than others. Recently, they’ve also focused on variations in the rate of aging among individual members of the same species, which they suspect might result from differences in the animals’ genetics, environment or behaviors.
Fun fact: Why are flamingos pink?
Flamingos get their vibrant pink color from their food—the birds dine on lots of brine shrimp and algae, which both contain red-orange pigments called carotenoids. As flamingos digest this food, the pigment gets processed by the liver and ultimately stored in the feathers and skin.
To explore these variations, scientists turned to greater flamingoes living in the Camargue, a region on the southern coast of France. Here, scientists at the Tour du Valat research institute have been gathering information about the birds that inhabit the Camargue’s Mediterranean wetlands for more than 40 years, thanks to a robust tagging and tracking program.
For the new paper, researchers analyzed mortality and reproduction data for 1,840 banded greater flamingoes. Some of the birds in the study, which the scientists categorized as “residents,” opted to hunker down and spend each winter in continental France. Others, dubbed “migrants,” flocked to warmer locales in southern Spain, Italy and North Africa when the temperatures began to drop each year.
These differing migratory strategies appear to affect the way the birds age. The resident birds seem to fare better than the migrants early in their lives, enjoying greater reproductive success and higher survival rates at the beginning of adulthood.
Migratory flamingos, by contrast, have higher mortality rates and lower reproductive success as young adults, as they undertake dangerous seasonal journeys. But they seem to make up for these disadvantages later in life, when they age more slowly than residents. On average, migrants start aging 1.5 years later than residents, per the study.
Scientists say these findings largely support an “early benefits to residents” hypothesis, which suggests there are some trade-offs between migrating and staying put.
“While residents can reproduce more often early in life, this comes at a cost: higher mortality and reduced reproductive success later on,” study co-author Jocelyn Champagnon, an ecologist at Tour du Valat, tells Gizmodo’s Ellyn Lapointe. “Migrants, on the other hand, may trade off some early reproduction for better survival later in life.”
Scientists don’t know exactly how and why the decision to migrate seems to affect the birds. But, zooming out, the findings suggest that individual choices—such as whether to stay or go—can and do have a big impact on aging in the wild.
For now, the results apply only to flamingos. But in the future, scientists might be able to expand on this research to explore how human decisions influence aging. More broadly, this line of inquiry might help scientists eventually solve some of life’s greatest mysteries: How and why do all living things eventually die? And is it possible to slow—or even reverse—aging, to the point that we could stave off death?
“Understanding the causes of changes in the rate of aging is a problem that has obsessed researchers and polymath philosophers since ancient times,” says lead author Hugo Cayuela, an ecologist at the University of Oxford in England, in a statement.
/https://tf-cmsv2-smithsonianmag-media.s3.amazonaws.com/accounts/headshot/SarahKuta.png)