Anna’s hummingbird and ruby-throated hummingbird are two different species of hummingbirds found in North America. While they may look similar to the untrained eye, they have several key differences in their physical appearance, habitat, range, diet, and behavior.
Physical Appearances
The most noticeable difference between Anna’s and ruby-throated hummingbirds is the color of the male’s throat feathers. As the name suggests, male ruby-throated hummingbirds have a bright ruby red throat, while male Anna’s hummingbirds have iridescent rose-pink throats with some small green feathers mixed in. The females of both species lack the brilliant throat patches and are quite similar in appearance – green backs, grey undersides, white eyerings, and dark, straight bills.
In terms of size, ruby-throats are smaller. They measure 7-9 cm long with a wingspan of 8-11 cm and weigh 2-6 grams. Anna’s hummingbirds are larger, measuring 10-12 cm long with a wingspan of 11-15 cm and weighing 3-7 grams.
One distinguishing feature of Anna’s hummingbirds is their slightly decurved bills, meaning the tips tilt slightly downward. Ruby-throated hummingbirds have straight, needle-like bills. Additionally, male Anna’s hummingbirds have an iridescent rose-red crown, while male ruby-throats lack a colored crown.
Habitats
Ruby-throated hummingbirds are found mainly in deciduous forests and forest edges in eastern North America. They thrive in areas with flowering plants and artificial feeders. During winter, they migrate to Central America.
Anna’s hummingbirds inhabit chaparral, suburban gardens, and parks along the Pacific Coast from southern British Columbia to Baja California. Some populations are migratory while others are residential year-round, especially in coastal California. Anna’s hummingbirds are comfortable in urban and suburban settings.
Ranges
Here are the breeding and year-round ranges of each species in North America:
| Species | Breeding Range | Year-Round Range |
|---|---|---|
| Ruby-throated Hummingbird | Eastern and central United States and southeastern Canada | Central America |
| Anna’s Hummingbird | Southwest Canada to northwest Mexico | Along Pacific Coast from British Columbia to Baja California |
As you can see, there is essentially no overlap between their breeding ranges, with ruby-throats in the east and Anna’s in the west. The year-round range of Anna’s hummingbirds extends along coastal California, an area not inhabited by ruby-throated hummingbirds.
Diets
Both Anna’s and ruby-throated hummingbirds have a diet comprised mostly of nectar, tree sap, and small insects. They use their specialized long tongues to drink nectar from tubular flowers. Some key differences in their diets include:
- Ruby-throats prefer the nectar of red or orange tubular flowers such as cardinal flower, trumpet creeper, and bee balm.
- Anna’s hummingbirds visit a wider variety of flowering plants and are drawn to red flowers as well as purple, pink, yellow, and white.
- Anna’s hummingbirds supplement more heavily with tree sap, specifically from sap wells they drill into pine trees.
- Ruby-throats eat more small insects such as gnats, fruit flies, spiders, and aphids.
This variance in their diets is likely linked to the different native plants and trees found in their respective habitats.
Behavior and Reproduction
Ruby-throated hummingbirds are solitary and aggressively defend their feeding territories from other males and females. Males perform elaborate courtship displays to attract females. Once mated, the female alone builds the nest out of plant down and spider webs on the branch of a deciduous tree. She lays 2 white eggs in a season, and the eggs hatch after 12-16 days.
Anna’s hummingbirds exhibit less territorial behavior and dominance displays between males. Their courtship displays are also less showy compared to ruby-throats. Anna’s hummingbird nests are neatly woven cups of plant down, feathers, and spider webs attached to tree limbs, wires, or other structures. The female lays just 1-2 eggs. She alone incubates the eggs for 14-19 days before they hatch.
Conclusion
In summary, Anna’s and ruby-throated hummingbirds may appear similar as diminutive, nectar-feeding birds with iridescent plumage. However, they inhabit different regions of North America, have distinct physical features, vary slightly in diet, and exhibit some differences in courtship behavior and nesting habits. While related, they are definitively considered separate species. An easy way to distinguish them is by their geographic location – Anna’s hummingbirds along the Pacific Coast and ruby-throated hummingbirds in eastern North America.
