|Size:||Length: 3 to 4 inches (7 to 10 cm) Wingspan: 5 inches (12.7 cm)|
|Weight:||1/10 to 1/8 ounce (2.8 to 3.5 g)|
|Diet:||Nectar and tiny insects|
|Distribution:||Eastern North America, Central America and West Indies|
|Young:||2 chicks, one to three times per year|
|Animal Predators:||Orioles, hawks and praying mantis|
|IUCN Status:||No special status|
|Lifespan:||Up to 5 years|
· Hummingbirds can hover, fly backwards, forwards, upside down or sideways.
· Female ruby-throated hummingbirds are generally 15 to 25 percent larger than males.
· Hummingbirds need to visit thousands of flowers each day to obtain enough food to survive.
· Ruby-throated hummingbirds play an important role in pollinating 31 different plant species.
Hummingbirds get their name from the humming sound that occurs from their rapid wing beats. Ruby-throated hummingbirds are a bright, metallic green with white undersides—the name for this particular type of hummingbird comes from the red patch that only the males have on the throat area. They have a long, thin bill that is used to extract nectar from flowers.
Ruby-throated hummingbirds live in eastern North America and migrate to the south for winter, returning as early as February to the southern U.S., depending on when the flowers in their area begin to bloom. Hummingbirds live in areas that provide plenty of flowers, open spaces, and trees.
They feed by hovering in front of a flower and dipping their long bills inside to feed on the nectar and tiny insects found inside. Hummingbirds are especially attracted to plants with red flowers.
The breeding season begins in March and ends in July. The female builds the nest in five to 10 days. Thistle and dandelion are laid down on the fork of a branch, attached by spider webbing. She then stamps down the base with her feet, and builds up the walls from plant down, bud scales and small pieces of bark. The cup-shaped nest is laced together with spider silk and the exterior is decorated with lichens. During courting rituals, the hummingbirds’ wing beats may increase up to 200 beats per second from the usual wing beat of 90 times per second. Males perform a courting display that consists of diving down towards the female, moving backwards along the same path, and then repeating these movements, similar to the way in which a pendulum swings back and forth. Males are polygamous and do not stay around to help with the offspring. The pea-sized eggs usually hatch in 10 days. The chicks emerge with their eyes shut, and are only able to raise their heads. Their eyes open in nine days and at 15 days they begin to learn to use their wings. The female may actually build a second nest in anticipation of a second brood, while caring for the first two chicks. The fledglings will begin to leave the nest from 18 to 22 days of age, but will return for feedings for another four to seven days. At approximately one month of age, the youngsters can fend for themselves.
When hummingbirds feed from a flower, pollen from the stamen is rubbed off on their heads. Hummingbirds then carry it to the next plant, pollinating as they go. Hummingbirds have extremely high metabolisms—they are active 17 hours per day, and need to consume twice their weight in food, or 7000 calories, within that time to sustain themselves.
Ruby-throated hummingbirds have become one of the few migratory bird species whose population is increasing—by approximately 1.5 percent in the U.S. per year. According to the US Fish & Wildlife Service, this is largely due to people who make hummingbird food sources readily available.
Ruby-throated Hummingbird Wildlife Fact File, IM Pub, US
Harrison, C. and Greensmith, A. (1993). Birds of the World. London: Dorling Kindersley Limited
National Geographic Field Guide to the Birds of North America, Third Ed. (1999)