The One in a Million Cardinal

March 11, 2021 7:29 PM

Bird week continues on MetaFilter with the spotting of a rare yellow cardinal in western Illinois. It is believed there are around a dozen of these cardinals in the eastern US and Canada at any given time out of a population of 50 million.
posted by JoeZydeco (16 comments total)

Here's the previous thread on the yellow cardinal spotted in Alabama in 2018.
posted by Johnny Assay at 8:56 PM on March 11, 2021 [2 favorites]

YES BirdFilter!
posted by esoteric things at 10:52 PM on March 11, 2021 [8 favorites]

"These [yellow] birds are not converting the yellow pigments they ingest in their diet to red. So, there's an enzyme that healthy northern cardinals have that allows them to convert the yellow dietary pigments to red plumage. And [yellow cardinals] don't have that — they don't have a functional version of that," Hill said.

"So presumably, it's a mutation, there was a change in the genetic code and the change caused that pigmentation system to fail," he said.

Hill told CBS News he hasn't seen a yellow cardinal in person, but he wasn't surprised to get a call about a yellow cardinal in Illinois. "It'd be like saying, 'Are you surprised to see this human blood disorder in Illinois, that we saw in these 15 other states?' And you'd say, 'No, there's people living in Illinois and this is a rare genetic mutation, and it can occur anywhere people live.' Same with Cardinals," Hill said.

He hopes any bird watchers who beat the less than one-in-million chance and see a yellow cardinal in person simply enjoy it: "Many bird watchers like me have spent a lifetime look at birds and never seen this. I've never seen a yellow variation of a red bird. All red birds essentially can show a yellow version just by having a mutation... And I've never seen that in any bird."

For it to be that rare I figured the enzyme must be involved in something else pretty important, and I found the answer in one of the links in the earlier post Johnny Assay linked to:

In his doctoral dissertation published in 1991, Hill studied whether female house finches, "the most common red bird you are going to get at your feeder," would prefer mates with yellow feathers or red feathers.

Females overwhelming preferred males with red plumage. But why do females prefer red?

This enzyme that does the conversion of yellow to red is in the mitochondria of cells, so it is linked to energy production, Hill said.

"We think this is what females want to know about," he added, meaning birds with red feathers seemingly have better mechanisms for energy production and thus will make better mates. "Calling a person (or animal) low energy is one of the biggest insults you can give."

And that in turn gives us greater insight into an observation made by Chelsea Curry, who noticed the Illinois bird at her backyard feeder:

Curry said when people see her photos of the yellow cardinal they usually have a similar reaction to her original surprise. "[The bird] usually comes at least three times a day, but sometimes he will hang around most of the day," she said.

"The worse the weather is, the more he shows up," she said, adding that in February, the bird would spend the entire day in their backyard, eating at their feeders.

posted by jamjam at 11:42 PM on March 11, 2021 [29 favorites]

I've seen yellow and orange male house finches, and they're definitely cool to see. But because they're not as boldly colored as male cardinals, they're not nearly as spectacular and spectacularly obvious as a yellow cardinal would be. Just another excuse to keep birding!
posted by mollweide at 5:03 AM on March 12, 2021 [1 favorite]

Who's a pretty birdie? You are! Yes, you are!
posted by Capt. Renault at 6:36 AM on March 12, 2021 [2 favorites]

Low energy, you say? Huh. Am I yellow?
posted by double bubble at 6:37 AM on March 12, 2021 [1 favorite]

"Calling a person (or animal) low energy is one of the biggest insults you can give."

Do you know how I know what corners of the internet you've been spending your time in?
posted by tigrrrlily at 7:17 AM on March 12, 2021 [1 favorite]

If I saw this bird in my yard, all I would ever do is bird-watch in my yard, all day (and I already spend a fair bit of time doing it, it's wonderful). What a beautiful and interesting mutation, but I hope it doesn't keep that cardinal from being able to mate.

Birds are great, but the more I watch them and learn about them, the more I appreciate civilization. Bird life is brutal, y'all.
posted by LooseFilter at 7:18 AM on March 12, 2021 [1 favorite]

A tiny flying sun
posted by Going To Maine at 8:54 AM on March 12, 2021 [3 favorites]

"We think this is what females want to know about," he added, meaning birds with red feathers seemingly have better mechanisms for energy production and thus will make better mates.

IANAEvolutionaryBiologist but I think this is backwards. Birds (probably) don't know about mitochondria or energy production vis a vis plumage hue. My guess is birds like the color of birds they're used to and not colors they're not used to.
posted by shesdeadimalive at 9:16 AM on March 12, 2021 [3 favorites]

So pretty! In other yellow bird news: Rare Yellow Penguin Bewilders Scientists
posted by Orange Dinosaur Slide at 9:49 AM on March 12, 2021 [1 favorite]

IANAEvolutionaryBiologist but I think this is backwards. Birds (probably) don't know about mitochondria or energy production vis a vis plumage hue. My guess is birds like the color of birds they're used to and not colors they're not used to.

I think the idea is that if the progeny of red males have more energy and can forage more successfully, then "being attracted to red males" is selected for among females. Any female whose has a genetic predisposition to mate with a red male is more likely to have her progeny survive.

Of course, the extent to which this idea is actually testable vs. a "just-so" story is unclear to me.
posted by Johnny Assay at 4:53 PM on March 12, 2021

Testable vs "just so" is an excellent way of putting it, thank you!

Also, this brutal headline about Hill's study: COSAM Professors Link Bird Coloration to Bird Quality

They're all good birds! You are quality to me, Yellow Cardinal.
posted by shesdeadimalive at 5:17 PM on March 12, 2021 [6 favorites]

if the progeny of red males have more energy and can forage more successfully, then "being attracted to red males" is selected for among females.

This makes sense as far as it goes, but it seems likely to be swamped by more direct mechanisms of sexual selection. If a red male cardinal is overwhelmingly preferred by mating partners, then even if red cardinals were inferior foragers, "being attracted to red males" would still be strongly selected for because any non-red male offspring would have poor mating prospects regardless of foraging ability.

I don't think red goldfinches are a thing, but I imagine a red goldfinch might face challenges similar to those faced by a yellow cardinal, matingwise.
posted by Not A Thing at 6:46 PM on March 12, 2021

Sketch of a proof for the existence of life on other worlds:
there are around a dozen of these cardinals in the eastern US and Canada at any given time out of a population of 50 million.

There are 50 million Cardinals in North America. Cardinals are endemic to North America, so this must represent the bulk of the population, with comparatively few in other places on Earth. However, there are an infinite number of Cardinals. These must exist somewhere, which means there must be Cardinals on other planets.

Counter argument: Cardinals are not Real.
posted by Joe in Australia at 2:04 AM on March 13, 2021 [1 favorite]

*Shout-out to everyone else at home frantically replacing the toner cartridges in their bird printers.*
posted by sebastienbailard at 8:51 PM on March 13, 2021 [3 favorites]