| Ruby-throated Hummingbird | |
|---|---|
 Adult male | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Aves |
| Order: | Caprimulgiformes |
| Family: | Trochilidae |
| Genus: | Archilochus |
| Species: | A. colubris |
The Ruby-throated Hummingbird (Archilochus colubris) is eastern North America's only breeding hummingbird. They zip from feeder to feeder in a blur of red as they search for energy to propel them on their 800-mile-long migration.
Taxonomy[]
The Ruby-throated Hummingbird was formally described by the Swedish naturalist Carl Linnaeus in 1758 under the binomial name Trochilus colubris in the tenth edition of his Systema Naturae . Linneaus based his description on the earlier account by Mark Catesby in his The Natural History of Carolina, Florida and the Bahama Islands that had been published in 1729 and the account by George Edwards in his A Natural History of Uncommon Birds that had been published in 1743. The type locality is South Carolina. The specific epithet colubris is from the Spanish colibrí meaning "hummingbird". The Ruby-throated Hummingbird is now placed in the genus Archilochus that was introduced in 1854 by the German naturalist Ludwig Reichenbach. The species is monotypic as no subspecies are recognized.
Appearance[]
Females lack the distinctive ruby throat of their male counterparts.
Adult hummingbirds have metallic green upperparts and grayish white underparts. Their short wings and tail feathers are near black. Hummingbirds have a long bill (up to 2 cm or .79 inches in length) purposed with extracting nectar. To fit the shape of tubular flowers, the bill is straight and very slender.
| Measurements | |
|---|---|
| Length: | 7 - 9 cm (2.8 - 3.5 in) |
| Weight: | 3.4 g (0.12 oz) (males); 3.8 g (0.13 oz) (females) |
| Wingspan: | 8 to 11 cm (3.1 to 4.3 in) |
As in all hummingbirds, the toes and feet of this species are quite small, with a middle toe of around 0.6 cm (0.24 in) and a tarsus of approximately 0.4 cm (0.16 in). The motion of the feet are quite limited; Ruby-throated Hummingbirds can only shuffle if it wants to move along a branch, though it can scratch its head and neck with its feet.
The species is sexually dimorphic. The adult male has an iridescent gorget (throat patch) with black lining around the auriculars. When viewed from certain angles, the gorget appears ruby. From other directions, it appears black. The tail in male hummingbirds is forked, black with a faint violet sheen. The female has a notched tail with outer feathers banded in green, black, and white and a white throat that may be plain or lightly marked with dusky streaks or stipples. Males are smaller than females and have slightly shorter bills.
Juvenile males hold heavy resemblance to adult females, though they usually have heavier throat markings. Furthermore, emerging metallic feathers can be observed in sub-adults.
Molting occurs once a year beginning in early fall and ending by late winter.
Occurrence[]
Distribuion. Map provided by the Cornell Lab of Ornithology. Data are provided by NatureServe in collaboration with Robert Ridgely, James Zook, The Nature Conservancy - Migratory Bird Program, Conservation International - CABS, World Wildlife Fund - US, and Environment Canada - WILDSPACE.
Ruby-throated Hummingbirds inhabit the deciduous and pine woodlands of eastern United states, east of the 100th meridian, as well as across the Canadian prairies. They also associate with old fields, forest edges, meadows, orchards, stream borders, and backyards.
Ruby-throated Hummingbirds are migratory, migrating from North America, passing the Gulf of Mexico and Caribbean to reach Panama, Mexico, or Florida. This journey takes them about 800 miles, with birds traveling up to 23 miles day.
Ecology[]
Before migration, hummingbirds will double their fat mass in preparation, then expand that energy in the 20-hour crossing when food and water are unavailable.
When temperatures drop, particularly on cold nights, ruby-throats may conserve energy by entering hypothermic torpor. The hummingbird will speed up its metabolism when temperatures return to normal.
Life History[]
Diet[]
Female hummingbird feeding on tubular flowers. It is true that they prefer red/orange/pink flowers, but this is an exception.
Nectar from flowers and flowering trees are the Ruby-throated Hummingbird's favorite food. They show a slight preference for orange, red, and pink tubular flowers, though flowers not adapted to hummingbird pollination, such as willow catkins, are also visited. When feeding from flowers, they will hover and insert their long bill into the flower, licking up the sap using their long tongue for up to ten times per second. Hummingbirds are also known to visit sapsucker wells to drink the sugar-rich sap or feed from hummingbird feeders.
Both young and adults alike feed on insects by catching them midair or gleaning them from flowers, leaves, bark, and spiders' webs. Insects prove to be an essential part of the bird's diet as they are a good source of protein, minerals, and vitamins.
Nesting[]
Males arrive at the breeding area in the spring and establish a territory before the females arrive. When the females return, males court females that enter their territory by performing courtship displays. They perform a "dive display" making a looping U-shaped dive rising 2.45–3.1 m (8.0–10.2 ft) above and 1.52–1.82 m (5.0–6.0 ft) to each side of the female. If the female perches, the male begins flying in very rapid horizontal arcs less than 0.5 m (1.6 ft) in front of her. If the female is receptive to the male, she may give a call and assume a solicitous posture with her tail feathers cocked and her wings drooped.
Ruby-throated Hummingbirds are thought to be polygynous, though polyandry and polygynandry may also occur. They do not form breeding pairs, with males departing immediately after the reproductive act and females being the sole constructor of the nest and providing all the parental care.
Females build their nests directly on top of a slender, often descending branch, usually of deciduous trees like oak, hornbeam, birch, poplar, hackberry, and on occasion, pine 10-40 feet (3.048-12.192 meters) off the ground. Nests have also been found on loops of chain, wire, and extension cords.
Nests are woven together using thistle or dandelion down held together with strands of spider silk and sometimes pine resin. The female stamps on the base of the nest to stiffen it, but the walls remain pliable. She shapes the rim of the nest by pressing and smoothing it between her neck and chest. The exterior of the nest is decorated (probably camouflaged) with bits of lichen and moss. The nest building process takes 6-10 days to finish, with the finished product measuring about 2 inches across and 1 inch deep.
Unlike most birds, hummingbirds reuse old nests but repair them annually.
Females lay 1-3 white eggs weighting about half a gram (less than one-fiftieth of an ounce) measuring 0.5-0.6 in (1.2-1.4 cm) in length and 0.3-0.3 in (0.8-0.9 cm) in width. Incubation takes 12-14 days and chicks hatch precocial. Brooding happens over a period of 12 to 14 days, by which point the chicks are feathered and homeothermic. The female feeds her young from 1 to 3 times every hour by regurgitation, usually while she continues hovering. When they are 18 to 22 days old, the young leave the nest and take their first flight.
Behavior[]
Like all hummingbirds, ruby-throats are precision fliers with the ability to fly full out and stop in an instant, hang motionless in midair, and adjust their position up, down, sideways, and backwards with minute control. They dart between nectar sources with fast, straight flights or sit on a small twig keeping a lookout, bill waving back and forth as the bird looks around. Hummingbirds are solitary and may defend territories, such as a feeding territory, attacking and chasing other hummingbirds that enter. However, hummingbirds usually yield to larger hummingbirds (in Central America) and the extremely aggressive Rufous Hummingbird.
Vocalization[]
At daybreak, males will sing a monotone string of chips. During courtship, the male will make a rapid tik-tik tik-tik tik-tik sound using its wings. This sound is produced at each end of the side-to-side flight during the shuttle display and dive displays. A faint whining sound is sometimes produced with the outer tail feathers during the dive as the male flies over the female while spreading and shutting his tail as he does so.
When a threat has been identified, Ruby-throated Hummingbirds will make rapid, squeaky chirps. A common call is an even chee-dit used when chasing a intruder from one's territory.
Flight[]
Hummingbirds propell themselves on a swift, forward flight with rapid wing beats of wings rotating 180 degrees; about 53 times per second. This creates a quiet humming sound, with males louder and higher pitched than females.
Longevity[]
The oldest hummingbird ever recorded was a 9 year and 1 month old female recaptured and rerealeased during banding operations in West Virginia. Almost all hummingbirds of 7 years or more in age are females, with males rarely surviving past 5 years of age. Reasons for higher mortality in males may include the higher demand for energy in males due to the high energetic demands of defending a territory followed by energetically costly migration, causing in weight loss.
Hummingbirds are rarely preyed upon due to their manuverability in flight, but occasionally, they will be caught by small, swift raptors including the Sharp-shinned Hawk, Merlin, American Kestrel, and Mississippi Kite as well as domestic cats, Loggerhead Shrike and even Greater Roadrunner, all of which are likely to ambush the hummingbird while it sits or sleeps on a perch or are distracted by breeding or foraging activities. Predatory lizards and bird-eating snakes may also prey on the species, especially on its tropical wintering grounds. Even large, predatory invertebrates have been known to prey on Ruby-throated Hummingbirds, including Praying Mantises (which have been seen to ambush adult hummingbirds at hummingbird feeders on more than one occasion), orb-weaver spiders, and Green Darners. Blue Jays are common predators of nests, as well as several other corvids in addition to some blackbirds, bats, squirrels, and chipmunks.
Conservation[]
Ruby-throated Hummingbird populations have steadily increased every year from 1966 to 2014, according to the North American Breeding Bird Survey. Partners in Flight estimates a global breeding population of 20 million with 84% spending some part of the year in the U.S., 51% in Mexico, and 16% breeding in Canada. The species rates an 8 out of 20 on the Continental Concern Score. The Ruby-throated Hummingbird is not on the 2014 State of the Birds Watch List. Hummingbird feeders are generally safe for hummingbirds, but may be hazardous if they are placed near windows, increasing the chances of a window collision, or allow them to fall prey to domestic cats.