The Ruby-throated Hummingbird is one of the most widespread and familiar hummingbird species in North America. The males are easily identified by their bright metallic green upperparts and glittering ruby-red throat. But what about the females – do they have any red coloring?
Quick Answer
The quick answer is no, female Ruby-throated Hummingbirds do not have any red feathers. The females have white undersides and green upperparts without any red on the throat or elsewhere on the body. This distinct sexual dimorphism sets the Ruby-throated Hummingbird apart from some other hummingbird species where the females may also display some reddish or orangey colors.
Detailed Answer
Here is a more detailed look at the plumage differences between male and female Ruby-throated Hummingbirds:
Males
- Chin, throat, and chest are iridescent ruby-red
- Upperparts are metallic green
- Flanks are grayish
- Belly and undertail are white
- Outer tail feathers are ruby-red at the base
Females
- No red anywhere
- Entire underparts white
- Upperparts metallic green
- Chin and throat white
- Belly and undertail coverts white
- Outer tail feathers rufous at the base
The vibrant ruby-red gorget (throat patch) on the male is highly iridescent and can appear black in low light. This gorget is absent in females. The red color comes from refracted light rather than pigment. In the right light, it can glow brightly and flash like a tiny nebula.
Why Such a Difference?
This striking sexual dimorphism is related to differences in the behavioral roles of males and females. The brilliant red throat patch of the male Ruby-throated Hummingbird is thought to serve multiple functions:
- Visual signal to attract females for mating
- Communication with other males during competition for mates and territories
- Possibly extra stimulation of females during courtship
Since the female does not play the same role in courtship displays, there has likely been little evolutionary advantage for her to maintain a costly red gorget. The differences in plumage characteristics allow the sexes to more efficiently fulfill their respective reproductive duties.
Appearance Changes
There are some slight seasonal and age-related changes in the appearance of male and female Ruby-throated Hummingbirds:
| Season | Male | Female |
|---|---|---|
| Breeding | Brightest red gorget | Brightest green upperparts |
| Nonbreeding | Gorget may be less bright | Plumage colors less lustrous |
| Age | Male | Female |
|---|---|---|
| Juvenile | Some reddish spots on throat | Duller green upperparts |
| Adult | Full red gorget | Brighter green upperparts |
But the basic pattern holds – adult females lack any substantial red coloring throughout the year. Only the males sport the ruby throat patch that gives this hummingbird its name.
Exceptions
There are very rare exceptions when female Ruby-throated Hummingbirds have been observed to display some red markings:
- Partial red spotting on the throat
- A few red feathers on the forehead
- Tiny patch of color on the bill or tongue
But these are abnormal occurrences probably resulting from a genetic mutation or other developmental anomaly. The vast majority of female Ruby-throated Hummingbirds remain bereft of red plumage throughout their lives.
Identification Tips
When identifying a hummingbird with even a small amount of red on the gorget, it is nearly always going to be a male Ruby-throated. For females and young birds, look for these characteristics:
- Entirely white underside
- Metallic green back and crown
- Some rufous color at base of outer tail feathers
- Small size and slender build
The female Ruby-throated Hummingbird is unlikely to be confused with any other species, provided the observer looks for the definitive absence of any red feathering.
Comparison with Other Hummingbird Species
The sexual dimorphism in the Ruby-throated Hummingbird is more pronounced than in some other co-occurring hummingbird species. Here is a quick comparison:
| Species | Male | Female |
|---|---|---|
| Ruby-throated | Red gorget | No red |
| Black-chinned | Purple gorget | Some red or orange on throat |
| Anna’s | Red gorget | Some red on throat |
| Costa’s | Purple gorget | No gorget |
| Rufous | Red gorget | Some orange on throat |
As seen above, the complete lack of any red plumage is unique to female Ruby-throated Hummingbirds among some commonly overlapping species. This makes the female definitively identifiable by this key marking (or rather, lack of marking).
Conclusion
In conclusion, while the male Ruby-throated Hummingbird is adorned with its iconic bright red gorget, the female is decidedly devoid of any reddish feathering. She retains the white underside and green upperparts throughout the year as she goes about the important business of nesting, incubating, and raising chicks. Her more subdued plumage is likely an evolutionary adaptation to her non-display roles. Next time you see a dash of red go by, it’s almost certainly a male. But if your hummingbird shows no hint of red at all, you can confidently identify it as a female Ruby-throated.
