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Why Yellow Woodpeckers Are Turning Red

This yellow-shafted flicker looks a bit pinkish in this photo by the USGS's Scott Somershoe via Wikimedia Commons // Public Domain


 
Northern flicker woodpeckers come in two color schemes, depending on where they’re from. Although all the birds are brown and black on top, the subspecies that lives in western North America—the red-shafted flicker—has red feathers on the underside of its wings and tail. Its cousin from the eastern side of the continent, the yellow-shafted flicker, has—you guessed it—yellow feathers in those spots. Seems simple enough, but scientists estimate that nearly one-third of yellow-shafted flickers also have orange or red feathers, and odd-colored woodpeckers are found far east of where the two subspecies overlap, potentially producing hybrids. More and more flickers are red where they shouldn’t be, in more ways than one.

A team of researchers has a new explanation for this color shift: Invasive plants are altering the woodpeckers’ palate—and, as a result, their palette. In short, they're eating things that are changing their colors.

Previously, some scientists had speculated that there was a factor selecting for red feathers, pushing the yellow-shafted flickers to evolve to look more like the red-shafted ones. Others suggested that the flickers were genetically capable of developing either color, and sometimes birds just grew feathers in the wrong shade.

But ornithologist Jocelyn Hudon, of the Royal Alberta Museum in Ontario, thought something else was responsible. A miscolored bird’s feathers, he noticed, can differ in shade from one year to the next. Other east coast birds that normally have yellow feathers—like cedar waxwings and Baltimore orioles—also sometimes have orange or red feathers. Maybe, Hudon, thought, something the birds were eating was causing these color changes. That's how flamingos get their color.

To find out, Hudon and his colleagues analyzed the "aberrant" feathers on a few yellow-shafted flickers they captured in Massachusetts and Pennsylvania, and compared them to museum specimens of yellow-shafted, red-shafted, and hybrid flickers collected across Canada. As they explain in an upcoming paper in the journal The Auk: Ornithological Advances, they found that the yellow-shafted flickers’ red feathers weren’t colored by the same carotenoid pigments responsible for the colors of red-shafted flickers, but by a pigment called rhodoxanthin.

Data from birders that had banded and tracked hundreds of flickers over the last 30 years told the scientists that the birds acquire the red pigment and shift colors during their fall molt in August and September, a time of year that the flickers mix fruit into their ant-based diet. That led Hudon to the likeliest source of the rhodoxanthin: Tatarian and Morrow’s honeysuckles, a pair of invasive plants native to Central Asia that produce abundant berries loaded with rhodoxanthin right around the time of the flickers’ molt.

The berry theory would explain why the red yellow-shafted flickers don’t display any traits of red-shafted flickers beyond feather color (there’s no hybridization); why many yellow-shafted flickers have both red and yellow feathers (the rhodoxanthin only affects feather growth after berries are eaten); and finally, why the red color appears abruptly and can differ or disappear (as rhodoxanthin is cleared from a bird’s system, the color fades). The feather color is affected by when the berries are ingested and how many are eaten.

Hudon’s team thinks that rhodoxanthin may cause color changes in other birds too—and have consequences on their love lives. While yellow-shafted and red-shafted flickers frequently mate with each other and pay no mind to color, many other species use feather color to identify and assess potential mates. For these birds, a meal that changes their hue could lead to problems finding a partner. Though their feathers might be red, they could be left feeling blue.

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Courtesy of The National Aviary
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Animals
Watch This Live Stream to See Two Rare Penguin Chicks Hatch From Their Eggs
Courtesy of The National Aviary
Courtesy of The National Aviary

Bringing an African penguin chick into the world is an involved process, with both penguin parents taking turns incubating the egg. Now, over a month since they were laid, two penguin eggs at the National Aviary in Pittsburgh, Pennsylvania are ready to hatch. As Gizmodo reports, the baby birds will make their grand debut live for the world to see on the zoo's website.

The live stream follows couple Sidney and Bette in their nest, waiting for their young to emerge. The first egg was laid November 7 and is expected to hatch between December 14 and 18. The second, laid November 11, should hatch between December 18 and 22.

"We are thrilled to give the public this inside view of the arrival of these rare chicks," National Aviary executive director Cheryl Tracy said in a statement. "This is an important opportunity to raise awareness of a critically endangered species that is in rapid decline in the wild, and to learn about the work that the National Aviary is doing to care for and propagate African penguins."

African penguins are endangered, with less than 25,000 pairs left in the wild today. The National Aviary, the only independent indoor nonprofit aviary in the U.S., works to conserve threatened populations and raise awareness of them with bird breeding programs and educational campaigns.

After Sidney and Bette's new chicks are born, they will care for them in the nest for their first three weeks of life. The two penguins are parenting pros at this point: The monogamous couple has already hatched and raised three sets of chicks together.

[h/t Gizmodo]

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holidays
Bleat Along to Classic Holiday Tunes With This Goat Christmas Album
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iStock

Feeling a little Grinchy this month? The Sweden branch of ActionAid, an international charity dedicated to fighting global poverty, wants to goat—errr ... goad—you into the Christmas spirit with their animal-focused holiday album: All I Want for Christmas is a Goat.

Fittingly, it features the shriek-filled vocal stylings of a group of festive farm animals bleating out classics like “Jingle Bells,” “Rudolph the Red-Nosed Reindeer,” and “O Come All Ye Faithful.” The recording may sound like a silly novelty release, but there's a serious cause behind it: It’s intended to remind listeners how the animals benefit impoverished communities. Goats can live in arid nations that are too dry for farming, and they provide their owners with milk and wool. In fact, the only thing they can't seem to do is, well, sing. 

You can purchase All I Want for Christmas is a Goat on iTunes and Spotify, or listen to a few songs from its eight-track selection below.

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