Overview
Plain-capped Starthroat: Medium-sized hummingbird with iridescent bronze-green upperparts and head, red throat, white face interrupted by black eyestripe, and pale gray underparts. Slightly notched tail is bronze-green with white-tipped black terminal band. Direct and hovering flight.
Range and Habitat
Plain-capped Starthroat: Casual to rare visitor to the U.S. in southeast Arizona; common in Mexico. Preferred habitats include tropical deciduous forests, cottonwood-willow streamside forests, and oak woodlands.
Hummingbirds (Trochilidae)
ORDER
The taxonomic order APODIFORMES (pronounced a-poh-dih-FOR-meez) is composed of four families of birds that occur on all continents except for Antarctica and includes masters of flight such as the swifts and hummingbirds.
FAMILY TAXONOMY
A family restricted to the Americas, the Trochilidae (pronounced tro-KIL-luh-dee), or hummingbirds, is one of the largest bird families with three hundred and thirty-eight species in one hundred and six genera.
NORTH AMERICA
One hundred twenty species of hummingbirds in fifty genera occur in North America. In addition to species with hummingbird as part of their name, these minute flying gems also include the poetically named hermits, streamertails, coquettes and violetears.
KNOWN FOR
Hummingbirds are mostly known for their tiny size and flying abilities. These hyperactive, insect-like birds can hover in place and fly backwards on wings that beat so fast they become a blur.
PHYSICAL
Most North American hummingbird species are tiny birds, most not much larger than a medium-sized butterfly, with thin, pointed bills, very short legs, and long wings for their dynamic flying. Just as impressive in flight, the large Magnificent and Blue-throated Hummingbirds of the southwest are roughly the same size as some warblers.
COLORATION
Most hummingbirds in North America have white underparts and glittering green upperparts. Exceptions are the Green Violetear with its mostly green plumage, the dark-bellied Magnificent Hummingbird, and the tan plumages of Rufous and Allen's Hummingbirds. Males of most hummingbirds also have a glittering, jewel-like patch of feathers on the throat known as a gorget that can reflect brilliant red, purple, copper, or other colors depending upon how the light strikes it.
GEOGRAPHIC HABITAT
Absent from the boreal forests and tundra of the far north, hummingbirds occur further south in both deciduous and coniferous forests, second growth, chaparral, and deserts. While just one species is regular in the east (the Ruby-throated Hummingbird), the southwestern United States hosts several species.
MIGRATION
Short and long distance migrations are undertaken by hummingbird species with the Ruby-throated Hummingbird routinely flying across the Gulf of Mexico to reach its wintering grounds in Central America.
HABITS
Generally solitary in nature, hummingbirds are very aggressive in defense of their food sources. This feisty behavior becomes immediately apparent when several hummingbirds congregate at feeders and flower patches, seeming to spend more time fighting and chasing each other around than actually feeding. Although hummingbirds will glean arthropods from spider webs and catch small bugs in flight, they mostly feed on flower nectar.
CONSERVATION
Perhaps due to their small size and flower-feeding behavior, no hummingbird species is threatened in North America; however habitat loss in Central and South America has placed some species in the vulnerable or endangered status categories.
INTERESTING FACTS
On cold nights hummingbirds can slow down their heart rate and metabolism to enter a temporary state of hibernation called torpor. This behavior allows the hummingbird to save precious energy demanded by its high rate of metabolism. Prior to naturalists understanding the widespread use of migration by birds, many early ornithologists assumed hummingbirds were too small to fly long distances and therefore rode on the backs of geese and other larger birds.