Order: APODIFORMES Family: Hummingbirds (Trochilidae)
The Ruby-throated Hummingbird is about 3.5 inches and weighs about 1/8 ounce. The adult male has an emerald green back, iridescent ruby red gorget (throat), gray flanks, forked tail with no white and is smaller than the female. The adult female is similar to the male except it has a white breast and throat, rounded tail with white tips and a longer bill. Young of both sexes look like the adult female.
The Ruby-throated Hummingbird's wings average about 52 beats per second and their normal flight speed is 30 mph. Most winter in Mexico, Central America, and on Caribbean islands, although a few remain in the Gulf States and the Outer Banks of North Carolina.
The birds make a remarkable non-stop crossing of the Gulf, crossing in 18-20 hours, to start the journey to their summer breeding grounds throughout the eastern half of North America. They arrive at the coast in late February or early March, and follow the development of spring flowers northward. Males migrate earlier than females. You can follow the migration on the maps at www.hummingbirds.net.
Courtship is very brief and once mated the female builds a nest and raises the young alone. The walnut-sized nest, constructed near the tip of a downsloping branch, below a leaf canopy and above a fairly open area, starts with spider silk to attach the nest and make it flexible. Lichens camouflage the outside, and the inside is lined with cotton from nesting material, dandelion, cattail, or thistle down. The nest will stretch to contain the growing nestlings, and may sometimes be reused the following year.
Two white, pea-sized eggs are laid two or three days apart, which the female will incubate from 60 to 80 percent of the day for 10-14 days. When they leave the nest, 18-22 days later, the chicks are twice as large as their mother which was stressed by raising them. After leaving the nest, fledglings are fed by their mother for about 10 days. Ruby-throated hummingbirds can raise up to three broods each year.
It is thought that Ruby-throats live as long as 12 years, but the average is probably 3-5 years. A group of hummingbirds has many collective nouns, including a "bouquet", "glittering", "hover", "shimmer", and a "tune" of hummingbirds.