Flashy Feathers AND a Great Song? Yep, It's Possible After All

New study challenges long-held belief that birds only have one flashy trait.

You can either have colorful feathers or a complex song, but not both. Or so scientists have long believed when it comes to birds. Now, new research shows that some birds can, in fact, have it all.

The long-held "trade-off" theory goes that bright feathers and complicated songs, both strategies males use to impress the ladies, take a lot of energy to develop—and anyway, female birds tend to prefer just one showy trait in a partner. As long as the gals don't care, it's most cost-effective for guys to excel at just one trait.

But researchers from San Diego State University analyzed data from more than 300 tanager species—one of the most diverse groups of songbirds in the world—and found no relationship between song and plumage complexity, they reported recently in Proceedings of the Royal Society B: Biological Sciences. It seems the two traits evolved independently from one another, meaning tanagers can have all kinds of combinations of the two: complex song only, flashy feathers only, neither, or—yes—both.

"It could be that what is costly in one species might not be costly in another species," says Nick Mason, lead author on the paper. But it could also be that these trade-offs only occur on a smaller scale when it comes to tanagers. When the researchers zoomed in on certain sub-families, they found that plumage and song complexity seemed to be linked, whereas the patterns dissolved when they considered the birds as a complete family. "I think what our results really show is that this constraint doesn't really exist at the largest, macroevolutionary scale," Mason says. Trade-offs could still be a factor at the sub-family or even genus levels, he adds.

As an added plus of the study, the fabulous birders at the Cornell Lab of Ornithology used the researchers' data on plumage and song complexity to publish top-10 lists of the tanagers with the most—and least—complex songs and feathers, which we're including below.  Check out Cornell's post here for more information.  

Most complex plumage

1. Paradise Tanager
2. Opal-rumped Tanager
3. Glistening-green Tanager
4. Blue-winged Mountain-Tanager
5. Golden-hooded Tanager
6. Green-headed Tanager
7. Black-chested Mountain-Tanager
8. Opal-crowned Tanager
9. Grass-green Tanager
10. Black-chinned Mountain-Tanager

Most complex songs

1. Merida Flowerpiercer
2. Chestnut-bellied Flowerpiercer
3. Slaty-backed Hemispingus
4. Masked Flowerpiercer
5. Rufous-browed Hemispingus
6. Gray-bellied Flowerpiercer
7. Bananaquit
8. Lacrimose Mountain-Tanager
9. Drab Hemispingus
10. Plushcap

Check out the chestnut-bellied flowerpiercer's intricate song:


[Recording by Jeremy Minns]

Simplest plumage

1. Black Flowerpiercer
2. Sooty Grassquit
3. Large Cactus-Finch (one of the Darwin’s finches!)
4. Black-throated Grosbeak
5. Carbonated Sierra-Finch
6. White-shouldered Tanager
7. Variable Seedeater
8. Small Ground-Finch  (one of the Darwin’s finches!)
9. Plumbeous Sierra-Finch
10. Slaty Finch

Simplest songs  

1. White-bellied Seedeater
2. Yellow-winged Tanager
3. Black-winged Saltator
4. Buff-breasted Mountain-Tanager
5. Red-crested Cardinal
6. Paramo Seedeater
7. Slate-colored Grosbeak
8. Black-throated Grosbeak
9. Brazilian Tanager
10. Chestnut-bellied Mountain-Tanager

Listen to the white-bellied seedeater's simple song:


[Recording by Jeremy Minns]