The scarlet tanager is a bright red and black songbird found in eastern North America. With its striking plumage, melodious song, and elusive nature, it has captivated birdwatchers for generations. But is this eye-catching bird related to the familiar northern cardinal? To find out, we’ll take a closer look at the scarlet tanager’s classification, physical characteristics, habitat, diet, and other traits to see how it compares to cardinals.
Taxonomy and Classification
The scarlet tanager belongs to the taxonomic family Thraupidae, commonly known as tanagers. More specifically, it is classified in the genus Piranga and species rubra. The northern cardinal, in contrast, belongs to the family Cardinalidae. So while both birds possess the word “cardinal” in their common names, they are not actually closely related.
Cardinals are grouped with other familiar backyard birds like buntings and grosbeaks in the Cardinalidae family. Tanagers like the scarlet tanager belong to the Thraupidae family, which includes other tropical species found in Central and South America. So the scarlet tanager is more closely related to birds like honeycreepers and euphonias than to the northern cardinal.
This classification based on evolutionary relatedness was determined through extensive study of the birds’ anatomy, physiology, behavior, geographic distribution, genetics, and other factors. While they may seem superficially similar due to their bright red plumage, the northern cardinal and scarlet tanager evolved those colorations independently through convergent evolution.
Appearance and Physical Features
The scarlet tanager and northern cardinal do share some physical similarities, especially in the male plumage. Male scarlet tanagers are a vivid scarlet red color over most of their body, with black wings and tail feathers. Male northern cardinals are also a deep red overall, with black faces and reddish bills.
However, there are some key differences. The red color of the cardinal tends to be more of an orangey shade, while the tanager is a true, bright scarlet. Tanagers also lack the distinctive crest that cardinals have on their heads. And up close, the shape of the bill is different – conical for tanagers and heavy with a curved tip for cardinals.
Females of the two species look quite different. Female scarlet tanagers are olive-yellow with darker wings and tails. Female cardinals, in contrast, are pale brown overall with reddish accents in the wings, crest, and tail.
Scarlet tanagers are slightly smaller than cardinals, averaging about 7 inches long with a wingspan around 11 inches. Cardinals are usually 8-9 inches long with a 12-13 inch wingspan. Tanagers weigh around 1 ounce, while cardinals can be 1.5-2 ounces.
Key Physical Differences
- Male tanagers are bright scarlet red, while male cardinals are more orange-red.
- Tanagers lack the cardinal’s crest.
- Tanagers have conical bills, cardinals have heavy curved bills.
- Female tanagers are yellow-olive, female cardinals are brownish.
- Tanagers are slightly smaller than cardinals in length and weight.
Habitat and Range
Northern cardinals and scarlet tanagers occupy broadly overlapping ranges across eastern and central North America. However, they tend to frequent different types of habitats within that range.
Cardinals are very adaptable birds that do well in a wide variety of habitats, including forests, thickets, backyards, parks, and agricultural areas. They thrive in edge habitats that provide a mix of trees, shrubs, and open space.
Scarlet tanagers prefer more extensive forest interiors, especially mature deciduous or mixed forests. They rely on large tracts of unbroken woodlands, and are sensitive to fragmentation and development.
In terms of elevation, cardinals can be found from sea level up to around 10,000 feet in mountainous areas. Scarlet tanagers are more restricted, breeding mainly below 3,000 feet and wintering primarily in lowland tropical forests in South America.
So while cardinals and tanagers overlap across much of the eastern half of North America, cardinals utilize a much broader array of habitats. Tanagers depend more strictly on interior forest environments.
Habitat Preferences
Bird | Preferred Habitats |
---|---|
Northern Cardinal | Forest edges, thickets, backyards, parks, farms, etc. |
Scarlet Tanager | Mature deciduous and mixed forests |
Diet and Feeding
As members of different families, northern cardinals and scarlet tanagers have evolved different bill shapes and feeding behaviors.
Cardinals have thick, heavy bills suited to cracking seeds and hard foods. The bulk of their diet consists of seeds and grains, including corn, oats, sunflower seeds, berries, and the like. They supplement this with insects like beetles, cicadas, and snails.
With their slender, pointed bills, scarlet tanagers are adapted for a different mode of feeding. Their diet is composed almost entirely of insects, with some fruit. Skimming and aerially hawking through the forest canopy, they eat wasps, bees, moths, butterflies, flies, spiders, and more.
So while cardinals are primarily seedeaters that supplement with insects, tanagers are aerial insectivores that opportunistically take some fruit. This difference in feeding styles has evolved in tandem with their bill morphology.
Diet Preferences
Bird | Primary Diet | Foraging Strategy |
---|---|---|
Northern Cardinal | Seeds, grains, berries | Gleans seeds from ground; eats from feeders |
Scarlet Tanager | Insects | Aerially catches insects in canopy |
Behavior and Voice
The behavior and vocalizations of northern cardinals and scarlet tanagers also reflect their differences as species, despite some superficial similarities in appearance.
Northern cardinals are non-migratory, remaining resident throughout their breeding range year-round. They are also highly vocal, with loud whistles and chip notes used to declare territory and stay in contact with their mate. Males will sing throughout the year.
In contrast, scarlet tanagers are long-distance neotropical migrants that breed in North America but winter in South America. They are far more secretive and elusive than cardinals, keeping hidden in the forest canopy much of the time. Their song is not persistent, but a series of choppy phrases interspersed with pauses.
Cardinals are also more social than tanagers outside of the breeding season, moving, roosting, and sometimes even nesting in loose flocks. Tanagers are solitary for most of the year, only interacting with their mate and offspring during breeding.
In terms of intelligence and problem-solving, cardinals likely have the edge over tanagers. As resident birds exposed to human environments like bird feeders, cardinals exhibit more innovative foraging behaviors to take advantage of food resources.
Behavioral Differences
Trait | Northern Cardinal | Scarlet Tanager |
---|---|---|
Migratory Status | Non-migratory | Long-distance migrant |
Vocalization | Loud whistles and chips | Choppy, sporadic song phrases |
Sociability | Can be social outside breeding season | Solitary for most of year |
Innovation | More innovative at feeders | Less behavioral flexibility |
Reproduction and Nesting
The breeding ecology of northern cardinals and scarlet tanagers also shows key differences due to their evolution within separate families.
Cardinals often nest in backyards, thickets, and other semi-open habitats. The nest is an open cup built 2-10 feet off the ground out of twigs, grass, and other plant materials. Females lay 2-5 eggs that incubate for 11-13 days. Both parents feed the young, which leave the nest at around 9-11 days old.
Scarlet tanagers nest high in the canopy of mature forests, 30+ feet up. Their nest is similarly a shallow open cup, but made of rootlets and constructed on a horizontal branch. Females lay 3-5 eggs that incubate for 12-14 days. The altricial young are fed by both parents and fledge from the nest after 9-12 days.
So while aspects like clutch size, incubation period, and nestling period are fairly similar, the nest placement and construction show key adaptations to their preferred habitats. Cardinals nest low in semi-open areas, while tanagers nest high in closed-canopy forest.
Breeding Comparison
Trait | Northern Cardinal | Scarlet Tanager |
---|---|---|
Nest Placement | Low, 2-10 ft up | High in canopy, 30+ ft up |
Nest Materials | Sticks, grass, plant fibers | Rootlets |
Clutch Size | 2-5 eggs | 3-5 eggs |
Incubation Period | 11-13 days | 12-14 days |
Nestling Period | 9-11 days | 9-12 days |
Conservation Status
Both the northern cardinal and scarlet tanager are currently species of Least Concern according to the IUCN Red List. This means they are abundant and widespread birds that are not currently vulnerable to extinction.
Cardinals have actually expanded their range over the past 200 years, taking advantage of deforestation and habitat fragmentation to move north and west across North America. Their population trends are increasing thanks to their adaptability.
Scarlet tanagers have likely declined somewhat from historical times due to forest clearing, but remain common and widespread overall. Their reliance on interior mature forests makes them more sensitive to habitat loss than cardinals, however.
So while neither species is endangered, the scarlet tanager is more of a conservation priority going forward due to its specialist habitat requirements. Monitoring this species can serve as an indicator of the health of eastern North American forests.
Conservation Status
Bird | IUCN Status | Population Trend |
---|---|---|
Northern Cardinal | Least Concern | Increasing |
Scarlet Tanager | Least Concern | Likely decreasing |
Conclusion
While the northern cardinal and scarlet tanager share vivid red plumage and overlapping ranges, they belong to different taxonomic families that have diverged through millions of years of evolution. This is reflected in key differences in their anatomy, habitat preferences, feeding behavior, lifestyle, and other traits that provide clues to their evolutionary histories.
Cardinals are non-migratory seedeaters well-adapted to semi-open habitats like forest edges and backyards. Tanagers are long-distance migratory insectivores dependent on large tracts of mature deciduous forest. Comparing these two iconic red birds provides great insights into the diversity of the avifauna of eastern North America.
So in summary, despite some superficial similarities, the scarlet tanager is not in the cardinal family. But both birds remain widespread and can be readily observed across much of the continent, delighting bird enthusiasts with their beautiful plumage and behaviors.