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The Ruby-throated Hummingbird (Archilochus colubris) is a species of hummingbird. They have the fastest wing-beat (wing flap) of a bird, 200 beats per second as opposed to the normal 90 beats per second produced by all other hummingbirds.
As with all hummingbirds, this species belongs to the family Trochilidae and is currently included in the order Apodiformes. This small animal is the only species of hummingbird that regularly nests east of the Mississippi River in North America.
The Ruby-throated Hummingbird is the smallest bird species that breeds in the Eastern United States and Eastern Canada. This hummingbird is from 7 to 9 cm (2.8 to 3.5 in) long and has a 8 to 11 cm (3.1 to 4.3 in) wingspan. Weight can range from 2 to 6 g (0.071 to 0.212 oz), with males averaging 3.4 g (0.12 oz) against the slightly larger female which averages 3.8 g (0.13 oz). Adults are metallic green above and greyish white below, with near-black wings. Their bill, at up to 2 cm (0.79 in), is long, straight, and very slender. 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 Ruby-throated Hummingbird can only fox-trot 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 a gorget (throat patch) of iridescent ruby red bordered narrowly with velvety black on the upper margin and a forked black tail with a faint violet sheen. The red iridescence is highly directional and appears dull black from many angles. The female has a notched tail with outer feathers banded in green, black, and white and a red 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 resemble adult females, though usually with heavier throat markings. The plumage is molted once a year, beginning in late summer.
The breeding habitat is throughout most of eastern North America and the Canadian prairies, in deciduous and pine forests and forest edges, orchards, and gardens. The female builds a nest in a protected location in a shrub or a tree. Of all hummingbirds in the United States, this species has the largest breeding range.
The Ruby-throated Hummingbird is migratory, spending most of the winter in southern Mexico and Central America, as far south as extreme western Panama, and the West Indies. It breeds throughout the eastern United States, east of the 100th meridian, and in southern Canada in eastern and mixed deciduous forest. In winter, it is seen mostly in Mexico.
Ruby-throated Hummingbirds are solitary. Adults of this species are not social, other than during courtship (which lasts a few minutes); the female also cares for her offspring. Both males and females of any age are aggressive toward other hummingbirds. They may defend territories, such as a feeding territory, attacking and chasing other hummingbirds that enter.
As part of their spring migration, portions of the population fly across the Gulf of Mexico. This feat is impressive, as a 800 km (500 mi), non-stop flight over water would seemingly require a caloric energy that far exceeds an adult hummingbird's body weight of 3 g (0.11 oz). However, researchers discovered the tiny birds can double their lean mass in preparation for their Gulf crossing. The additional mass, stored as fat, provides enough energy for the birds to achieve the flight.
Hummingbirds have many skeletal and flight muscle adaptations which allow the bird great agility in flight. Muscles make up 25–30% of their body weight, and they have long, blade-like wings that, unlike the wings of other birds, connect to the body only from the shoulder joint. This adaptation allows the wing to rotate almost 180°, enabling the bird to fly not only forward but fly backward, and to hover in front of flowers as it feeds on nectar or hovers mid-air to catch tiny insects. Hummingbirds are the only known birds that can fly backward.
During hovering, (and likely other modes of flight) ruby-throated hummingbird wings beat 55 times per second.
Nectar from flowers and flowering trees, as well as small insects and spiders, are its main food. Although hummingbirds are well known to feed on nectar, small arthropods are an important source part of protein, minerals, and vitamins in the diet of adult hummingbirds. Hummingbirds show a slight preference for red, orange, and bright pink tubular flowers as nectar sources, though flowers not adapted to hummingbird pollination (e.g., willow catkins) are also visited. Their diet may also occasionally include sugar-rich tree sap taken from sapsucker wells. The birds feed from flowers using a long, extendable tongue and catch insects on the wing or glean them from flowers, leaves, bark, and spiders' webs.
As typical for their family, Ruby-throated hummingbirds are thought to be polygynous. Polyandry and polygynandry may also occur. They do not form breeding pairs, with males departing immediately after the reproductive act and females providing all parental care.
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” 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.
The nest is usually constructed on a small, downward-sloping tree limb 3.1 to 12.2 m (10 to 40 ft) feet above the ground. Favored trees are usually deciduous, such as oak, hornbeam, birch, poplar or hackberry, although pines have also been used. Nests have even been found on loops of chain, wire, and extension cords. The nest is composed of bud scales, with lichen on the exterior, bound with spider's silk, and lined with fibers such as plant down (often dandelion or thistle down) and animal hair. Most nests are well camouflaged. Old nests may be occupied for several seasons, but are repaired annually. As in all known hummingbird species, the female alone constructs the nest and cares for the eggs and young.
Females lay two (with a range of 1 to 3) white eggs about 12.9 mm × 8.5 mm (0.51 in × 0.33 in) in size and produce one to two broods each summer. They brood the chicks over a period of 12 to 14 days, by which point they are feathered and homeothermic. The female feeds the chicks from 1 to 3 times every hour by regurgitation, usually while the female continues hovering. When they are 18 to 22 days old, the young leave the nest and make their first flight.
The oldest known Ruby-throated Hummingbird to be banded was 9 years and 1 month of age. 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 loss of weight during the breeding season due to the high energetic demands of defending a territory followed by energetically costly migration. A variety of animals prey on hummingbirds given the opportunity. Due to their small size, hummingbirds are vulnerable even to birds and other animals which generally feed on insects. Chief among their predators are Sharp-shinned Hawks, domestic cats, and loggerhead shrikes, all of which are likely to ambush the hummingbird while it sits on a perch. Bird-eating lizards and snakes may also prey on the species, especially on its tropical wintering grounds. Even large, predacious invertebrates have preyed on Ruby-throated Hummingbirds, including praying mantises, orb-weaver spiders, and Green Darners. Blue jays are common predators of nests.
Bird call of the Ruby-throated Hummingbird (Archilochus colubris)
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The vocalizations of Ruby-throated Hummingbirds are rapid, squeaky chirps, which are used primarily for threats. For example, males may vocalize to warn another male that has entered his territory.
During the courtship displays, the male makes a rapid tik-tik tik-tik tik-tik sound, apparently with his wings. The sound is produced both during the shuttle display, at each end of the side-to-side flight. Also, the sound is made during dive displays. A second, rather faint, repeated whining sound is sometimes produced with the outer tail-feathers during the dive, as the male flies over the female, spreading and shutting the tail as he does so.
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