Ruby-throated Hummingbird

The Ruby-throated Hummingbird is the only hummingbird that nests in eastern North America, so in most of the East a summer hummingbird is this one. It is tiny and metallic green above, with a long, slender bill and short wings that do not reach the end of the tail when it perches.

The adult male's throat is a gorget of iridescent feathers. Caught by the light it glows ruby red, but in shade it often looks black, and from the side it can glint gold or green. Above it, a black chin and face run back to a small white spot behind the eye; the chest is pale, darker and greenish along the sides, and the tail is dark and forked.

Adult females have no red. Their throat and underparts are plain whitish with buffy flanks, a dusky mask runs through the eye, and the three outer tail feathers on each side have broad white tips.

It is 2.8-3.5 in (7-9 cm) long, with a wingspan of 3.1-4.3 in (8-11 cm), and weighs 0.1-0.2 oz (2-6 g). An average adult weighs about a tenth of an ounce (3 g): males about 3.0 g and females about 3.5 g. Females are the larger sex, with longer wings and longer bills. In a large Alabama banding sample, males averaged 3.36 g (397 birds) and females 3.81 g (483 birds).¹

Weight swings with the seasons. Before and during migration they fatten fast: heavily fattened birds in northern Alabama weighed 4.7-6.0 g, and in fall, birds landing on the Alabama coast were on average about 30% above their lean weight, some more than 90% above it.¹

Only adult males have a red throat. A female's throat is plain and pale, though a few females 5 or 6 years old grow up to 5-6 red feathers in the middle of it.¹ Males also have a black chin and mask and a dark, forked tail with no white, while females have a dusky mask, buffy flanks and white tips on the outer tail feathers.

The male's gorget changes with the angle. Facing the sun it is brilliant red; turned away it can look black. Some males show an orange tinge to the gorget from late summer into winter, perhaps as the feathers age, though the cause is not settled.

Young birds out of the nest look like adult females, their fresh green upperparts finely fringed gray to cinnamon, fringes that soon wear away. A young male's throat is streaked or spotted with dusky marks, his white tail tips are smaller, and from late summer many grow a few scattered red gorget feathers. A young female has a cleaner white throat with few or no spots and no red, and more white in the tail, so she is very hard to tell from an adult female.

Throat streaks are not a perfect guide: some authors call them unreliable for sexing young birds, and banders measure the wing instead: a wing under 43 mm marks a male, a rule reliable for about 95% of birds.¹ Young birds get adult plumage in their first winter, when they molt on the wintering grounds, and a few young males come back in spring with the gorget still incomplete.

The closest lookalike is the Black-chinned Hummingbird, its closest relative and the only other member of its genus, whose range has been spreading in Oklahoma, Texas and Louisiana. The adult male Black-chinned's gorget is purple rather than red, though in poor light both look dark. Females and young are harder: on a perched bird, a Black-chinned's wingtips reach the tip of the tail or a little past it, while a Ruby-throated's tail reaches well beyond its wings, and with care a Ruby-throated female shows, on average, a brighter green crown and back. Where the two meet they sometimes interbreed: in southwestern Oklahoma, 11 males (9.3% of the males caught) had gorgets of an in-between color.¹

A female Anna's Hummingbird is larger, bulkier and dingier, with greener-washed sides, and a male Anna's has glittering color on the forehead as well as the throat, but the two rarely meet. A male Broad-tailed Hummingbird has a rose-magenta gorget and no dark mask, and female and young Broad-tailed Hummingbirds show cinnamon in the tail, which is green and black on a Ruby-throated. Rufous Hummingbirds do not breed in its range, but some winter on the Gulf Coast (see Winter range).

Unlike singing hummingbirds such as Anna's, the Ruby-throated has only a rudimentary song-control area in the male's brain, undeveloped in the female, and what passes for its song is a run of chips. Its usual sounds are rapid, squeaky chips, often run together into a twittering chatter when birds chase each other. At daybreak, a male on territory gives a steady, monotonous run of chips from a high, open perch, and neighboring males answer.

Most calls are threats. A study of calls recorded during fights at feeders found five kinds of notes, pitched above 10 kHz and strung together into calls and chatter, plus a harsh W note always given alone and always by the winner; the bird that called won 95% of the recorded encounters, and 70% of the time it was the resident.^{2, 1}

Females give a soft mew before mating and at the nest, scold with smoother, less raspy notes than males, and make quiet tic-tic notes while feeding. Late in the breeding season the chatter gives way to tew and tic-tic calls, and in fall migration both sexes give a repeated chee-dit, especially where many gather. On their wintering grounds in Costa Rica they are usually quiet.

The wings make sounds too. Both sexes hum as they fly, the male's narrower, pointed flight feathers giving a higher, more variable hum. In normal flight the wings beat about 70 times a second in males and 52 in females.¹ In courtship the male's wings buzz loudly as he swings back and forth in front of a female, and make a sharp rattling crackle at the low point of each dive.

This is the hummingbird of eastern North America, and no other North American hummingbird breeds over so large an area. It breeds from the Maritimes, southern Quebec and central Ontario west across the Prairie Provinces to central Alberta, and south to the Gulf Coast and central Florida. On the Great Plains the western edge runs almost due north and south, a little east of the 100th meridian, close to the edge of the eastern forests.

In summer look for it in open deciduous and mixed woods, woodland clearings and edges, old fields, orchards, parks and gardens; in the Southeast it nests in pine woods too. It is easiest to see at flowers and sugar-water feeders, and is common in suburbs and towns.

Yes: nearly all leave the US and Canada for the winter. In spring, males reach the Alabama coast from late February, 8-10 days ahead of the females, and the birds work north to southern Ohio by late April and the New Brunswick breeding grounds by mid-May.¹ They arrive earlier than they used to: comparing first-arrival records from 2001-2010 with those from 1880-1969, one study found spring arrivals across the eastern US 11-18 days earlier, with smaller changes north of about 41 degrees N.³

Adult males leave first. In Ohio most have gone by mid-August, and at Powdermill in western Pennsylvania by 9 September, while females and young birds stay into early October; on the Alabama coast, fall passage peaks from 7 September to 12 October, and the first birds reach Costa Rica in late September.¹ Young birds from all over the breeding range stop on the Gulf Coast in fall, southern-born birds first and northern ones later.⁴ In the north, fall migration comes close to the peak bloom of jewelweed, an important nectar flower that may help set its timing.⁵

Many cross the Gulf of Mexico in one flight over open water, and in spring large numbers are seen coming in low over the sea to land on the northern Gulf Coast. At a banding station on the southwest Louisiana coast, birds landing after the crossing peaked in the second half of April, males about three days ahead of females, and most did not stop to refuel: only 2% of marked birds were caught again more than a day later (1998-2007).⁶

Others go around, and fall may be different. Young birds radio-tracked as they left the Alabama coast in fall mostly set off to the east or west, by day, as birds going around the Gulf would, and average fall passage on the northern Yucatán coast comes more than a month after that on the Alabama coast, which also points to a route around the Gulf; many pass along the Texas coast in both seasons.¹ In fall, adults reach the northern Gulf Coast earlier and fatter than young birds and move on sooner.⁷

Most winter from southern Sinaloa on Mexico's Pacific side and southern Veracruz on the Gulf side, south through Central America to Costa Rica, and occasionally to western Panama, in dry tropical forest, second growth, scrub, hedgerows and citrus groves. They replace their flight feathers there, in a long molt that ends before they fly north.

A few winter in the US: in Florida south to the Keys, on the southeastern Atlantic coast and, in growing numbers, along the Gulf Coast. Winter banding in southern Alabama and northern Florida in 1998-2008 found Rufous Hummingbirds the commonest species (51.6%) and Ruby-throated second (23.5%);⁸ in 2008-2018 Ruby-throated made up 31% of the hummingbirds banded there, 583 birds.⁹ These winter birds are probably migrants from farther north rather than local breeders that stayed behind: one banded in winter in Florida was later found in New Brunswick, Canada.^{1, 9} Any winter hummingbird there is worth a close look, since it may be a western species.

Flower nectar and small insects. A Ruby-throated Hummingbird hovers at flowers to lap nectar with its long tongue, and comes to sugar-water feeders. It catches tiny insects in the air, picks them off leaves and bark, and plucks spiders and trapped insects from webs: mosquitoes, gnats, fruit flies and small bees, caterpillars, aphids and insect eggs. When flowers are scarce it drinks tree sap.

Insects may matter more than they seem. No one has measured how much of the diet they make up, but one rough estimate from droppings put the share perhaps as high as 50-60%.¹

It favors red, tubular flowers such as trumpet creeper, cardinal flower, jewelweed, wild columbine, bee balm, red buckeye and trumpet honeysuckle, and uses many garden flowers, salvias among them. Yet studies have found no strong preference for any one color: where a flower or feeder is, and perhaps its shape, matter more.¹ In return it pollinates many eastern flowers; in Illinois and Missouri, hummingbirds left 10 times as much trumpet-creeper pollen per visit as bumble bees and honey bees.¹

Early in spring, and in the far north, sap can stand in for flowers. Ruby-throats feed at the wells Yellow-bellied Sapsuckers drill in birches, and in the Southeast in tulip poplar and red maple, sometimes following a sapsucker to fresh wells and snapping up the insects the sap draws in. In northern Michigan, nesting females fed almost entirely on sap from sapsucker holes, and all six nests in the study were within about 1,000 ft (300 m) of a sapsucker's feeding tree.¹⁰ One study offered evidence for the idea that the hummingbird's spring arrival and how far north it breeds depend on sapsuckers, since in the far north it often arrives before the flowers open.¹¹

A sugar-water feeder is the easiest way to see one up close. Mix 1 part refined white sugar with 4 parts water, a quarter cup of sugar to a cup of water, using boiling water or bringing the mix to a boil, and let it cool before you fill the feeder.^{12, 13} Do not add red dye, since real nectar is clear and the red on the feeder is enough to draw the birds; and use only white sugar, never honey or artificial sweeteners.^{12, 13, 14}

Clean the feeder and refill it with fresh sugar water every day or two in hot weather and every few days when it is cooler, and at once if the water looks cloudy or shows mold.^{12, 15} Hang it where cats cannot lie in wait and away from windows: cats and window strikes may be among the worst dangers around feeders.¹⁴

Put a feeder out about a week before hummingbirds usually arrive where you live, and leave it up while any are around, and even for a while after they seem to have gone, since late migrants can still turn up.¹² There is no sign that leaving it up holds them back: the Missouri Department of Conservation says there is no evidence that feeders kept up late into fall delay migration,¹⁴ and a hummingbird bander in Louisiana reports none either.¹

Native flowers are the best natural source of nectar, with a feeder as a supplement; natives it visits include red buckeye, wild columbine, fire pink, royal catchfly, wild bergamot, jewelweed, cardinal flower, trumpet creeper and native honeysuckles.^{12, 14, 1}

The female does everything. She chooses the site, builds the nest, incubates the eggs and raises the young alone; the male plays no part after mating. She often starts building soon after she arrives. First eggs are laid from the fourth week of March in southern Louisiana and from the second week of April in central Alabama, and farther north egg dates run from May into August or even early September.¹

Most raise one or two broods a year, and a third brood has been recorded in Alabama. A female may start a second nest while she is still feeding the young from her first.

The nest is a tiny cup about the size of a thimble, usually saddled on a slender branch that slopes down, with open space below and leaves overhead. Most are in deciduous trees such as oak, hornbeam, birch, poplar and hackberry, sometimes in pines, usually 10-40 ft (3-12 m) up; some are built over water, and nests have even been placed on loops of chain, wire and extension cord.

She builds it in about 6-10 days from thistle or dandelion down bound with spider silk, sometimes with pine resin, and covers the outside with lichen. She stamps the base firm with her feet, but the walls stay soft and stretch as the chicks grow. The finished cup is about 2 in (45-50 mm) across at the base.

She lays two white eggs, sometimes one and rarely three, each about half an inch (13 mm) long and weighing about half a gram; of 77 nests in Ontario, 66 held two eggs, 10 held one and one held three.¹ She incubates them for 12-14 days, and they hatch a day or more apart. The chicks hatch almost naked, weighing about 0.62 g, with a little pale down along the back, and open their eyes after about a week.¹

She feeds them by pushing her bill deep into theirs and bringing up nectar and insects; from about two weeks old they also get small insects carried in her bill. The young leave the nest at 18-22 days, weighing more than an average adult female (about 4.85 g), then often lose weight, probably until they learn to find food; their mother feeds them for 4-7 days more.¹ More on the chicks: baby hummingbirds.

Many nests fail. In a five-year study in northwest Tennessee (2011-2015), 28 of 103 nesting attempts (27%) succeeded, from 7% to 64% in different years, and predators caused most of the failures.¹⁶

Hummingbirds do not use nest boxes. The female builds an open cup, usually on a branch, and we found no source that recommends a box.

Its flight is the thing to watch: fast and direct, able to stop dead, hover in place and fly backward. Its feet are too small for walking or hopping, so it can only shuffle along a perch, and it scratches its head by raising a foot up and over the wing. It bathes on wet leaves or in fine spray, and sometimes sunbathes, lying flat with its wings spread on a broad branch.

Timed over a measured course in Ontario, fall migrants flew at 16-39 mph (26-63 km/h).¹ In a lab study, captive birds kept hovering in gas mixtures of falling density until they failed at 47% of the density of sea-level air.¹⁷

They are aggressive, males above all. In the breeding season a male holds a territory around a food source, such as a patch of flowers or a feeder, and chases off other hummingbirds and songbirds that come near; fights can end in jabs with the bill. A bird threatening another spreads its wings and fans its tail, with a stream of chattering calls. Migrants defend feeders too, and Ruby-throats usually give way to larger hummingbirds, Rufous Hummingbirds included.

Crowding makes a feeder hard to keep to yourself. In a study of marked birds at 45 feeders spread over about 109 acres (44 ha), birds that stuck to certain feeders got more exclusive use of them, males against other males especially, but the more competitors there were, the less any one bird had a feeder to itself.¹⁸

There is no pair bond: males and females meet only to court and mate, and males are presumed to mate with several females. When a female comes into his territory, the male flies a U-shaped dive in front of her, swooping down from as high as 40-50 ft (12-15 m) and up again. If she perches, he switches to the shuttle display, swinging rapidly from side to side within about 1.5 ft (0.5 m) of her, gorget flared and wings buzzing.

Cold nights are a real danger for so small a bird. Ruby-throats often reach the north while nights are still near freezing, and they are presumed to survive them in torpor, a deep, sleep-like state in which the body cools and energy use drops; torpid birds have been found as far south as Alabama after a sudden cold snap.

Lab studies show how deep it goes. Fasting captive birds kept at 50°F (10°C) at night let their body temperature fall from about 99°F (37°C) to about 55°F (13°C) in torpor, and cut their energy use by 95%.¹⁹ In late summer, captive birds fattening for migration were more likely to go into torpor on nights when they carried more fat, and those that used more torpor gained more fat.²⁰

Many do not survive from one year to the next, males especially. In an 18-year study in South Carolina (1984-2001), the apparent annual survival of resident birds, which counts birds that moved away as lost, was 30% for males and 43% for females.²¹ At Powdermill in Pennsylvania, adults caught were mostly females, 3.1 to 1 in summer and 4.1 to 1 in fall, and the oldest returning male was 3 years old, half the oldest female's age; the authors suggest the smaller males may run short of energy overnight, when they cannot feed, or in bad weather; they judged that where each sex was caught likely also shaped the ratios.²²

Some live far longer. The oldest Ruby-throated Hummingbird on the USGS Bird Banding Laboratory's list was at least 11 years 1 month old when it was last caught: a female banded as an adult in Illinois on 14 June 2014 and caught again, alive, in Illinois on 27 July 2024, then released.²³ The record before it, still given in older lists, was a West Virginia female of at least 9 years 2 months, and every record bird on the list is a female.²³

Around feeders, domestic cats are likely the commonest predator. Small hawks and falcons take hummingbirds too, among them Sharp-shinned Hawks, Merlins and American Kestrels, as do Mississippi Kites, Loggerhead Shrikes, Baltimore Orioles and Eastern Kingbirds, praying mantises, dragonflies and frogs. Large orb-weaving spiders sometimes catch them: one paper listed 6 caught in webs, of which 5 died, and in 3 the spider ate the bird; a Blue Jay was once seen killing and eating a nestling.¹

Even so, predators are probably not a big risk for adult hummingbirds in temperate areas, where most recorded deaths are accidents, and on migration one bird was seen mobbing an American Kestrel, darting at its face until the falcon changed course.²⁴ Windows, towers and vehicles probably kill many, though few are counted, and birds can get caught on the burs of burdock.¹

It is common and widespread across the East in summer. Partners in Flight estimates about 36 million birds, from data around 2010, roughly 30 million in the United States and 6 million in Canada; it scores the species' conservation concern as low (8 of 20) and does not put it on its Watch List.^{25, 26}

Numbers rose for decades but have fallen since the mid-2000s. On the North American Breeding Bird Survey, which flags its results for this species with a deficiency (fewer than one bird is counted per route, one of the flag's triggers), counts were lowest from 1966 to 1974, peaked in 2004-2007 and have dropped since; over the whole period, 1966-2025, the trend is still a significant rise of 0.60% a year (95% credible interval +0.41 to +0.78), about 42% more birds, but from 2015 to 2025 counts fell significantly, by 1.35% a year (-2.00 to -0.70), about 13%, leaving 2025 about 23% below the peak.²⁷

Partners in Flight's reading of the same survey agrees: up 1.03% a year from 1970 to 2021, but down 0.84% a year from 2011 to 2021 (90% intervals).²⁵ A 2021 analysis found the fall began around 2004 across most of the breeding range, 17% by 2019, with no evidence that it was an artefact of changes in when the birds breed; it suggested that disturbance of the Central American dry forests where they winter may contribute.²⁸ The survey itself gives no cause.

The species is not threatened: the IUCN lists it as Least Concern (2021 assessment).²⁹ It is not listed under the US Endangered Species Act or Canada's Species at Risk Act.³⁰

In the United States the Ruby-throated Hummingbird is on the federal list of birds protected under the Migratory Bird Treaty Act, which makes it illegal to capture, kill or keep one, or to keep its nest, eggs or feathers, unless a federal permit allows it.^{31, 32} Anyone who finds a sick, injured or orphaned hummingbird may pick it up without a permit only to carry it directly to a licensed veterinarian or a permitted wildlife rehabilitator; caring for it at home is not allowed.³³

In Canada, hummingbirds are covered by the Migratory Birds Convention Act, 1994: the birds, their eggs and any nest with a live bird or a viable egg in it are protected.^{34, 35, 36} It is not on the list of species whose empty nests stay protected, and an injured bird may be held only to deliver it to a permitted rehabilitator.³⁶