Untouched colour/color photograph by J. McCombie.
A flash of green and red, the Ruby-throated Hummingbird (Archilochus colubris) is eastern North America’s sole breeding hummingbird and is the only species of hummingbird that regularly nests east of the Mississippi River. These brilliant, tiny, precision-flying creatures glitter like jewels in the full sun, then vanish with a zip toward the next nectar source. Feeders and flower gardens are great ways to attract these birds, and some people turn their yards into buzzing clouds of hummingbirds each summer.
The Ruby-throated Hummingbird is a small hummingbird with a slender, slightly downcurved bill and fairly short wings that don’t reach all the way to the tail when the bird is sitting. The Ruby-Throated Hummingbird is 7-9 cm (2.8-3.5 in) long and has a 8-11 cm (3.1-4.3 in) wingspan. Weight can range from 2 to 6 g (0.071-0.21 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 shuffle if it wants to move along a branch, though it can scratch its head and neck with its feet.
Ruby-throated Hummingbirds are bright emerald or golden-green on the back and crown, with gray-white underparts. Males have a has a ruby red throat patch, also known as a gorget which may appear black in some lighting, and a dark forked tail. The female has a dark rounded tail with white tips and generally no throat patch, though she may sometimes have a light or whitish throat patch. The male is smaller than the female, and has a slightly shorter beak. A molt of feathers occurs once a year, and begins during the autumn migration.
Ruby-throated Hummingbirds fly straight and fast but can stop instantly, hover, and adjust their position up, down, or backwards with exquisite control. During hovering, (and likely other modes of flight) ruby-throated hummingbird wings beat 55 times per second. 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 backwards, 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 backwards. They often visit hummingbird feeders and tube-shaped flowers and defend these food sources against others. You may also see them plucking tiny insects from the air or from spider webs.
Ruby-throated Hummingbirds live throughout most of eastern North America and the Canadian prairies, in deciduous and pine forests , forest edges, orchards, meadows, grasslands, and in parks, gardens, and backyards. The female builds a nest in a protected location in a shrub or a tree. Of all North American hummingbirds, this species has the largest breeding range.
Ruby-throated hummingbirds are solitary. Adults of this species are not social, other than during courtship (which lasts a few minutes), cares for her offspring. Both males and females of any age are aggressive towards other hummingbirds. They may defend territories, such as a feeding territory, attacking and chasing other hummingbirds that enter. In late summer to early fall they fatten up for migration. This is important because, as part of their migration, they must fly across the Gulf of Mexico. This feat is impressive, as a 500-mile, non-stop flight over water would seemingly require a caloric energy that far exceeds an adult hummingbird’s body weight of 3 grams. However, researchers discovered the tiny birds can increase their body mass up to double with lean mass in preparation for their Gulf crossing. The additional mass, stored as fat, provides enough energy for the birds to achieve the flight.