Red feathers are an unusual and striking feature found on some bird species. While not exceptionally rare, red plumage is less common than other feather colors like brown, black or white. The red coloration is produced by pigments in the feathers and can range from bright scarlet to a more muted rusty-red hue. Certain bird groups are more likely to have red feathers, especially tropical species like parrots, tanagers and cardinals. But even among these groups, truly all-red birds are uncommon. So while not the rarest of feather types, red plumage stands out due to its vibrant color and relative scarcity compared to more mundane shades.
What Causes Red Feathers?
Bird feathers get their color from pigments produced within the feather follicles. Red feathers contain high levels of reddish pigments like astaxanthin or canthaxanthin. But most birds lack the genetic ability to produce significant amounts of these red pigments. Their feathers are instead colored by other common pigments like melanins and carotenoids, which produce blacks, browns, yellows and oranges. Only certain bird lineages have evolved the capacity to create reddish pigments. This explains the relative rarity of red plumage across most avian families.
Bird Groups with Red Feathers
While uncommon overall, red feathers are more prevalent among particular taxonomic groups of birds:
Parrots
Parrots are famous for their bright plumage, including red. The red in parrot feathers comes from psittacofulvins, pigments unique to parrots. Many parrot species exhibit some red in their plumage, like scarlet macaws, red-lored amazons, and eclectus parrots. But even among parrots, exclusively red species are rare.
Tanagers
Tanagers are a diverse family of small passerines found in the Americas. They are one of the most colorful bird groups, with many species bearing red plumage. Red tanagers get their color from carotenoid pigments like lutein. Species like the summer tanager and scarlet tanager sport nearly all-red plumage.
Cardinals
Cardinals are finches common across North America. The bright red plumage of the male northern cardinal is iconic. The red comes from carotenoids obtained from food. Female cardinals are also reddish-brown. Cardinals demonstrate that red feathers don’t have to be limited to tropical species.
Weavers
The weaver family includes small passerines like bishops, widows and queleas. Males of several species have reddish plumage, like the red bishop and the red-billed quelea. These mostly consist of shades of orange-red, rather than scarlet.
Woodpeckers
While most woodpeckers have black, white and red head patterns, a few all-red species exist. The red-headed woodpecker of North America is one example. Pigments called psittacofulvins, similar to those in parrots, produce the red color in woodpeckers.
Rarity of All-Red Birds
While the groups above contain red-feathered species, birds with exclusively red plumage are uncommon. Here are some examples of rare, entirely red birds:
– Scarlet macaw – Bright red with blue flight feathers.
– Red lory – Small red parrot native to Indonesia.
– Vermilion flycatcher – Small American flycatcher. Males are bright red.
– Scarlet ibis – Wading bird with vivid red plumage.
So while red feathers occur across many bird families, species where red dominates the entire plumage are relatively scarce. Hybrids and color mutations can also sometimes produce all-red birds. Overall though, truly red birds stand out as anomalies against the more common green, brown and black-colored species.
Geographic Trends in Red Birds
Geography seems to play a role in the prevalence of red feathers. Tropical regions, especially South America and Southeast Asia, have the highest diversity of red-colored birds. Some patterns:
– Most red parrot species occur in central South America and Indonesia.
– Tanagers with red plumage mainly live in tropical Latin America.
– Northern cardinals with red males are widespread across temperate North America.
– Africa has fewer red bird groups, besides some weavers and widowbirds.
So red plumage appears more frequently in the tropics. Theories for this include:
– Greater availability of red pigment-producing foods.
– More intense sexual selection for bright red males to attract mates.
– Red blends in well amid lush vegetation in tropical forests.
This geographic trend adds to the overall rarity of red birds, which decline in prevalence further from the equator.
Red Feather Rarity in Other Bird Groups
Beyond the major red-feathered groups above, red plumage pops up sporadically in other bird families:
| Bird group | Examples of red species |
|---|---|
| Pigeons and doves | Bleeding-heart dove |
| Ducks | Red-crested pochard |
| Gamebirds | Red junglefowl |
| Cranes | Red-crowned crane |
| Tyrant flycatchers | Rufous-tailed plantcutter |
These scattered red species demonstrate that red plumage can appear almost anywhere in the avian family tree. But its rarity globally shows red feathers are an unusual trait outside of a few select bird groups.
Brightness and Sexual Selection
The brilliance of red plumage likely contributes to its rarity. Such bright colors take extra physiological effort to produce. And red stands out sharply against most backgrounds, making red birds conspicuous to predators. These costs mean intense sexual selection is often needed to drive the evolution of vibrant red males within a species. Females must have a strong preference for red males to offset the risks. The difficulty of maintaining such strong selection pressure may explain why red persists consistently across groups like parrots and tanagers, but only pops up sporadically elsewhere.
Conclusion
While eye-catching, red feathers are relatively uncommon in the avian world compared to more mundane browns and blacks. Red plumage reaches peak diversity in certain tropical lineages like parrots and tanagers. But all-red species remain rare even within these groups. Geographic and physiological constraints seem to prevent red from becoming a widespread feather type. So while stunning red birds exist, the inherent challenges of producing such vibrant coloration makes red feathers an exceptional novelty rather than the norm across most bird families. Their rarity is part of what makes red birds so visually striking to us.
