Status: Least Concern
Range & Habitat
The Ruby-throated Hummingbird is the smallest bird species that breeds in the Eastern United States and Eastern Canada. The Ruby-throated Hummingbird is migratory and spends most of the winter in southern Mexico and Central America, and as far south as extreme western Panama and the West Indies.
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 degrees, enabling the bird to fly not only forward but 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. During hovering, (and likely other modes of flight) ruby-throated hummingbird wings beat 55 times per second. 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. Breeding habitat is throughout most of eastern North America and the Canadian prairies, in deciduous and pine forests and forest edges, orchards, and gardens. Of all hummingbirds in the United States, this species has the largest breeding range. The vocalizations of Ruby-throated Hummingbirds are rapid, squeaky chirps, and are used primarily for threats.
Reproduction & Growth
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 provide all parental care. The nest is usually constructed on a small, downward-sloping tree limb. Females lay two (with a range of 1 to 3) white, and produce one to two broods each summer.
Nectar from flowers and flowering trees, as well as small insects and spiders, are its main food. Although hummingbirds are 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. Their diet may also occasionally include sugar-rich tree sap taken from sapsucker wells. Young birds are fed insects for protein since nectar is an insufficient source of protein for the growing birds.