Birds with ruddy plumage typically have reddish-brown feathers. This reddish coloring is caused by pigments called carotenoids that are ingested through the bird’s diet. Some common birds with ruddy plumage include the rufous-tailed robin, red-tailed hawk, northern cardinal, and American robin.
What causes the ruddy plumage in birds?
The ruddy or reddish-brown plumage seen in some birds is caused by carotenoid pigments in their diet. Carotenoids are organic pigments that are naturally occurring in many fruits, plants, and crustaceans. Birds that eat large amounts of carotenoid-rich foods will deposit these pigments into their feathers as they molt and regrow them. This gives their plumage a distinct red or reddish-brown color.
Some common carotenoids that contribute to ruddy plumage are:
- Astaxanthin – Found in krill, shrimp, and other crustaceans
- Beta-carotene – Found in fruits and vegetables
- Canthaxanthin – Found in insects and crustaceans
- Lutein – Found in green leafy vegetables
Birds that consume large amounts of these carotenoid sources will develop brighter and deeper reddish feathers. The specific type and amount of carotenoids they ingest influences the exact hue and saturation of the ruddy coloration.
What birds commonly have ruddy plumage?
Some birds that are known for having ruddy or reddish-brown plumage include:
- Rufous-tailed robin – A bird native to parts of South America. Males have bright reddish-orange plumage on their heads, tails, wings, and bellies.
- Red-tailed hawk – A common hawk of North America. It gets its name from its distinctive reddish-brown tail feathers.
- Northern cardinal – The male cardinal has vivid red feathers covering most of its body. The red color comes from carotenoids in seeds and fruit.
- American robin – Both male and female robins have reddish-orange breast feathers. The males tend to have richer, darker red coloring.
- Red-winged blackbird – The male has jet-black plumage except for orange-red shoulder patches on its wings.
- European robin – A familiar reddish-breasted bird of Europe, unrelated to the American robin.
The degree of red or ruddy coloring can vary considerably between individual birds based on age, sex, diet, and molting stage. In some species like cardinals, the males tend to be much more vibrantly colored than females.
What purpose does ruddy plumage serve in birds?
The reddish-brown plumage found in many bird species likely serves several different purposes:
- Camouflage – In some habitats, ruddy brown or red feathers can help birds blend in with dirt, clay soils, dead vegetation, and trees. This camouflage makes it easier to avoid predators and catch prey.
- Thermoregulation – Carotenoid pigments are thought to strengthen feathers and make them more resistant to wear and fading. This may help birds survive in sunny, abrasive, or hot environments.
- Attracting mates – In many species, males have brighter red plumage than females do. This coloring might play a role in attracting females during courtship.
- Social signaling – Vibrant plumage can help communicate dominance and fitness between birds of the same species.
The specific purpose likely depends on the particular species and its habitat. But in most cases, the ruddy reddish coloration provides camouflage, durability, courtship, or social advantages to the birds that display it.
What are some key facts about ruddy plumage in birds?
- Caused by carotenoid pigments from food sources like shrimp, fruit, and vegetation.
- Gives feathers red, reddish-brown, or orange hues.
- Seen in birds like cardinals, robins, red-tailed hawks.
- More vibrant in males of sexually dimorphic species.
- Probably serves functions like camouflage, heat resistance, attracting mates.
- Shade of color depends on specific carotenoids, quantities ingested.
- Plumage varies between individual birds based on diet, age, molting.
How can you identify a bird species based on its ruddy plumage?
There are a few key features to look for when identifying a bird species based on ruddy or reddish-brown plumage:
- Location of red/brown coloring – Note whether plumage is on the head, wings, tail, belly, etc. Different species have red in distinct areas.
- Exact hue – Color can range from deep burgundy to bright orangey-red. The hue provides clues to the species.
- Size and shape – Consider the bird’s overall proportions relative to the red plumage. This helps narrow the possibilities.
- Beak, legs, eye color – These other features combined with ruddy plumage identify the species.
- Geographic location – Whether an observation is made in North America, Europe, etc. limits the likely species.
Having a good visual reference guide or bird field book can help pinpoint the specific species when observing reddish-brown wild birds.
Conclusion
Ruddy or reddish-brown plumage is found in many common bird species, particularly those that consume diets rich in carotenoid pigments. This unique feather coloring likely serves functions such as camouflage, heat resistance, and attracting mates. Some notable ruddy birds include northern cardinals, American robins, red-tailed hawks, and Rufous-tailed robins. Identifying a specific bird by its red plumage takes practice observing key features like the hue, location on the body, size, beak shape, and geographic range. The vibrant red feathers play an important role in the lives of birds that display them.