Ruby-Throated Hummingbird (Archilochus colubris): The Complete Guide

Male Appearance

The adult male Ruby-Throated Hummingbird is one of the most recognizable birds in North America once you have seen him in good light. His upperparts --- back, crown, and rump --- are a lustrous metallic emerald green that shifts subtly between olive and jewel-green depending on the angle of sunlight. His underparts are a clean grayish-white, and his wings are near-black, appearing dark purple in certain light. The defining field mark is his gorget: a bib of iridescent feathers covering the throat and chin that can appear pure ruby-red, blood-orange, or outright black depending on how light strikes the specialized feather microstructure. In the field, a male seen in shade will appear to have a black throat until he turns toward the sun --- then the gorget ignites. His tail is distinctly forked, a useful feature visible in flight. The bill is long (roughly 20% of total body length), straight, and slightly decurved, perfectly engineered for probing tubular flowers.

Female Appearance

The female is slightly larger than the male and trades the gorget for a throat that is dull grayish-white --- clean and unmarked in most individuals, though some show faint dusky streaking. Her upperparts are the same metallic green as the male's. The most reliable field mark distinguishing her from other female hummingbirds in the East is the set of white tips on her outer three tail feathers, visible when the tail is fanned or spread during hovering. Her underparts are white, often with a faint buffy wash on the flanks. She lacks the forked tail of the male; instead, her tail is rounded or slightly notched. The bill is identical in shape to the male's.

Juvenile Appearance

Juveniles of both sexes closely resemble adult females on arrival from their first southward migration: green above, whitish below, with white-tipped outer tail feathers. Young males typically begin showing the first flecks of red feathering on the throat by late summer, and may arrive at wintering grounds with a patchy or speckled gorget rather than the solid ruby of a full adult male. By their first spring migration northward, most males have developed a complete gorget, though individuals in their first breeding season may still be distinguishable by feather wear and gorget quality. Young females are essentially inseparable from adult females in the field without banding data.

Similar Species & How to Tell Them Apart

In the eastern United States, the Ruby-Throated Hummingbird has no regular competition from other species --- it is the only breeding hummingbird. However, late summer and fall bring occasional western strays, making identification more nuanced:

• Rufous Hummingbird (Selasphorus rufus): increasingly recorded in the East in fall. Males are unmistakably orange-rufous; females show rufous wash on the flanks and base of the tail, absent in female Ruby-Throated.

• Black-Chinned Hummingbird (Archilochus alexandri): female nearly identical to female Ruby-Throated. Look for the distinctive tail-pumping behavior of Black-Chinned, their slightly longer bill, and a thinner neck profile. Range rarely overlaps.

• Allen's Hummingbird (Selasphorus sasin): accidental in the East. Very similar to Rufous; best separated in the hand by tail feather shape.

The Ruby-Throated Hummingbird undertakes one of the most demanding migrations of any North American songbird-sized bird. Most individuals complete a round trip of at least 1,600 kilometers between breeding and wintering grounds, with the iconic leg being the non-stop crossing of the Gulf of Mexico. At roughly 800--900 km of open water, this crossing takes approximately 18--22 hours of sustained flight at speeds up to 40 mph --- accomplished without rest, food, or water.

Spring migration timing:

• Gulf Coast (Texas, Louisiana): late February to mid-March

• Southeast (Alabama, Georgia, Carolinas): March--early April

• Mid-Atlantic (Virginia, Maryland): late March to mid-April

• New England and Great Lakes: late April to mid-May

• Southern Canada: mid-May onward

Males consistently arrive 1--2 weeks ahead of females on breeding grounds, establishing territories before females begin northward movement.

Fall migration timing:

• Adults begin departing breeding grounds in late July and August

• Peak southward movement through the Southeast: August--September

• Most birds have left the eastern US by mid-October

• Some individuals linger along the Gulf Coast into November

Before crossing the Gulf, Ruby-Throated Hummingbirds engage in hyperphagia --- intensive feeding to double their body mass from approximately 3--4 grams to 6--8 grams of fat-rich stored energy. This physiological preparation is critical; well-maintained feeders along coastal staging areas in late August and September may directly support birds preparing for this crossing.

The Ruby-Throated Hummingbird is the least fussy of all North American species when it comes to feeder selection --- it will use virtually any feeder design --- but certain choices will maximize attraction and bird health:

Feeder style: Both saucer-style (dish) and bottle-style feeders work well. Saucer-style feeders are easier to clean and less prone to dripping. Multiple smaller feeders placed out of line-of-sight from each other are more productive than one large feeder, as this reduces territorial monopolization by dominant males.

Color: Red is the most effective attractant color; most commercial feeders incorporate red plastic or red flower ports for this reason. Do not add red dye to the nectar to compensate for a non-red feeder --- the dye is unnecessary and potentially harmful.

Placement height: Hang feeders at 4--6 feet above ground, near (but not directly against) windows to reduce collision risk. Position near flowering plants and within 10--15 feet of perching branches, which birds use between feeding bouts.

Port size: Standard ports (approximately 3/8 inch opening) are ideal. Larger ports invite bees and wasps; bee guards are useful in high-insect areas.

Nectar freshness: In warm weather (above 80°F / 27°C), replace nectar every 2--3 days. In cooler conditions, every 4--5 days is sufficient. Any sign of cloudiness, fermentation, or black mold requires immediate cleaning with hot water and a bottle brush --- never bleach in quantities that leave residue. Clean feeders save lives.

Female Ruby-Throated Hummingbirds build their nests entirely alone --- the male contributes nothing beyond genetic material and departs before eggs are laid. The nest is a masterwork of miniaturization: a compact cup approximately 2 inches in diameter and 1 inch deep, constructed from thistle and dandelion down bound together with spider silk and camouflaged on the exterior with lichen flakes, bark fragments, and bud scales. The elasticity of the spider silk allows the nest to expand as the nestlings grow.

Nest placement favors small downward-sloping branches of deciduous trees, typically 10--30 feet above ground, often over water or open clearings. The nest is usually positioned on the upper surface of a sloping branch for structural support, oriented so the female faces outward.

• Clutch size: 2 eggs (occasionally 1; rarely 3)

• Incubation period: 12--14 days, by the female alone

• Nestling period: 18--22 days before fledging

• Broods per season: 1--3 in the Southeast; typically 1--2 in northern portions of range

Eggs are white, roughly the size of a small jellybean. After hatching, chicks are fed by the female via regurgitation --- a mixture of nectar and pre-digested insects inserted directly into the nestlings' mouths. Chicks develop rapidly; by day 18--22 they are flight-capable and begin short test flights from the nest rim before fully fledging.

The Ruby-Throated Hummingbird is classified as Least Concern by the IUCN Red List (2023), with an estimated breeding population of 34--36 million individuals. Population trend data from the North American Breeding Bird Survey shows a long-term increase from 1966 through the early 2000s, though a notable 17% decline was recorded in the most recent census period (reported 2021), indicating that vigilance is warranted even for common species.

Primary threats:

• Habitat loss on both breeding and wintering grounds, particularly tropical forest clearing in Central America

• Pesticide use --- both directly toxic and indirectly harmful through elimination of the insect prey base that hummingbirds require

• Window collisions --- a significant source of mortality; reflective glass is responsible for hundreds of millions of bird deaths annually in North America

• Cat predation --- outdoor cats are estimated to kill 1--4 billion birds per year in North America

• Climate-driven phenological mismatch --- shifts in flowering times can decouple flower availability from migration timing

What you can do:

• Maintain clean, dye-free feeders with fresh nectar through the full migration season (March--October in most of the East)

• Plant native flowering species that provide nectar for early-arriving and late-departing migrants

• Apply window collision deterrents (UV-reflective decals, exterior screens) on large glass surfaces

• Keep cats indoors or in enclosed outdoor spaces

• Reduce or eliminate pesticide and herbicide use in your yard

• Report banded birds to the Bird Banding Laboratory at the USGS