Anna's Hummingbird
Encyclopedia
Anna's Hummingbird is a medium-sized hummingbird
Hummingbird
Hummingbirds are birds that comprise the family Trochilidae. They are among the smallest of birds, most species measuring in the 7.5–13 cm range. Indeed, the smallest extant bird species is a hummingbird, the 5-cm Bee Hummingbird. They can hover in mid-air by rapidly flapping their wings...

 native to the west coast of North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

. This bird was named after Anna Masséna, Duchess of Rivoli
Anna Massena, Duchess of Rivoli
Anna Masséna, Duchess of Rivoli was the wife of Francois Victor Massena, 2nd Duke of Rivoli.Anna was the daughter of General Jean Francois Joseph DeBelle. She married Victor Massena in 1823. She later became Mistress of the Household to Empress Eugenie.René Primevère Lesson named "Anna's...

.

Description

Anna's Hummingbird is 3.9 to 4.3 inches (10 to 11 centimeters)long. It has a bronze-green back, a pale grey chest and belly, and green flanks. Its bill is long, straight and slender. The adult male has an iridescent
Iridescence
Iridescence is generally known as the property of certain surfaces which appear to change color as the angle of view or the angle of illumination changes...

 crimson-red
Crimson
Crimson is a strong, bright, deep red color. It is originally the color of the dye produced from a scale insect, Kermes vermilio, but the name is now also used as a generic term for those slightly bluish-red colors that are between red and rose; besides crimson itself, these colors include...

 crown and throat, and a dark, slightly forked tail. Anna's is the only North American hummingbird species with a red crown
Crown (anatomy)
A crown is the top of the head.The following birds and other animals are said to have a crown on their head:* Cranes** Grey-crowned Crane** Red-crowned Crane** Black-crowned Crane* Crowned eagle* Gray-crowned Rosy Finch* Yellow-crowned Gonolek...

. Females and juveniles have a green crown, a grey throat with some red markings, a grey chest and belly, and a dark, rounded tail with white tips on the outer feathers.

These birds feed on nectar from flower
Flower
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants . The biological function of a flower is to effect reproduction, usually by providing a mechanism for the union of sperm with eggs...

s using a long extendable tongue. They also consume small insect
Insect
Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...

s caught in flight. A PBS
Public Broadcasting Service
The Public Broadcasting Service is an American non-profit public broadcasting television network with 354 member TV stations in the United States which hold collective ownership. Its headquarters is in Arlington, Virginia....

 documentary
Documentary
A documentary is a creative work of non-fiction, including:* Documentary film, including television* Radio documentary* Documentary photographyRelated terms include:...

 that first aired January 10, 2010, shows how Anna's Hummingbirds eat flying insects (at 16:45).http://www.pbs.org/wnet/nature/episodes/hummingbirds-magic-in-the-air/video-full-episode/5475/ They aim for the flying insect, then open their beaks very wide. That technique has a greater success rate than trying to aim the end of a long beak at the insect.

While collecting nectar, they also assist in plant pollination
Pollination
Pollination is the process by which pollen is transferred in plants, thereby enabling fertilisation and sexual reproduction. Pollen grains transport the male gametes to where the female gamete are contained within the carpel; in gymnosperms the pollen is directly applied to the ovule itself...

. This species sometimes consumes tree sap.

Reproduction

Open-wooded or shrub
Shrub
A shrub or bush is distinguished from a tree by its multiple stems and shorter height, usually under 5–6 m tall. A large number of plants may become either shrubs or trees, depending on the growing conditions they experience...

by areas and mountain meadows along the Pacific
Pacific Ocean
The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.At 165.2 million square kilometres in area, this largest division of the World...

 coast from British Columbia
British Columbia
British Columbia is the westernmost of Canada's provinces and is known for its natural beauty, as reflected in its Latin motto, Splendor sine occasu . Its name was chosen by Queen Victoria in 1858...

 to Arizona
Arizona
Arizona ; is a state located in the southwestern region of the United States. It is also part of the western United States and the mountain west. The capital and largest city is Phoenix...

 make up C. annas breeding habitat. The female raises the young without the assistance of the male. The female bird builds a large nest in a shrub or tree, or in vines or on wires. The round, 3.8 to 5.1 cm (1.5 to 2 in) diameter nest is built of very small twigs, lichen and other mosses, and often lined with downy feathers
Down feather
The down of birds is a layer of fine feathers found under the tougher exterior feathers. Very young birds are clad only in down. Powder down is a specialized type of down found only in a few groups of birds. Down is a fine thermal insulator and padding, used in goods such as jackets, bedding,...

 or animal hair. The nest materials are bound together with spider silk or other sticky materials. They are known to nest early as mid-December and as late as June.

Unlike most hummingbirds, the male Anna's Hummingbird sings during courtship. The song is thin and squeaky. During the breeding season, males can be observed performing a remarkable display, called a display dive, on their territories. When a female flies onto a male's territory, he rises up approximately 30 metres (98.4 ft) before diving over the recipient. As he approaches the bottom of the dive the males reach an average speed of 27 m/s, which is 385 body lengths per second. At the bottom of the dive the male travels 23 metres per second (51.4 mph), and produces a loud sound described by some as an "explosive squeak" with their outer tail-feathers.

Anna's Hummingbirds will sometimes hybridize with other species, but this is not very common. These natural hybrids have been mistaken for new species. A bird, allegedly collected in Bolaños, Mexico, was described and named Selasphorus floresii (Gould, 1861), or Floresi's Hummingbird. Several more specimens were collected in California over a long period, and the species was considered extremely rare.
It was later determined that the specimens were the hybrid offspring of an Anna's Hummingbird and an Allen's Hummingbird
Allen's Hummingbird
The Allen's Hummingbird, Selasphorus sasin, is a species of hummingbird.The Allen's Hummingbird is a small bird, with mature adults reaching only 3 to 3½ inches in length. The male Allen's has a green back and forehead, with rust-colored rufous flanks, rump, and tail. The male's throat is also an...

. A single bird collected in Santa Barbara, California
Santa Barbara, California
Santa Barbara is the county seat of Santa Barbara County, California, United States. Situated on an east-west trending section of coastline, the longest such section on the West Coast of the United States, the city lies between the steeply-rising Santa Ynez Mountains and the Pacific Ocean...

, was described and named Trochilus violajugulum (Jeffries, 1888), or Violet-throated Hummingbird. It was later determined to be a hybrid between an Anna's Hummingbird and a Black-chinned Hummingbird
Black-chinned Hummingbird
The Black-chinned Hummingbird is a small hummingbird.Adults are metallic green above and white below with green flanks. Their bill is long, straight and very slender. The adult male has a black face and chin, a glossy purple throat band and a dark forked tail...

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Distribution

Anna's Hummingbirds are found along the western coast of North America, from southern Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...

 to northern Baja California
Baja California
Baja California officially Estado Libre y Soberano de Baja California is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is both the northernmost and westernmost state of Mexico. Before becoming a state in 1953, the area was known as the North...

, and inland to southern Arizona
Arizona
Arizona ; is a state located in the southwestern region of the United States. It is also part of the western United States and the mountain west. The capital and largest city is Phoenix...

. They tend to be permanent residents within their range, and are very territorial. However, birds have been spotted far outside their range in such places as southern Alaska
Alaska
Alaska is the largest state in the United States by area. It is situated in the northwest extremity of the North American continent, with Canada to the east, the Arctic Ocean to the north, and the Pacific Ocean to the west and south, with Russia further west across the Bering Strait...

, Saskatchewan
Saskatchewan
Saskatchewan is a prairie province in Canada, which has an area of . Saskatchewan is bordered on the west by Alberta, on the north by the Northwest Territories, on the east by Manitoba, and on the south by the U.S. states of Montana and North Dakota....

, New York
New York
New York is a state in the Northeastern region of the United States. It is the nation's third most populous state. New York is bordered by New Jersey and Pennsylvania to the south, and by Connecticut, Massachusetts and Vermont to the east...

, Florida
Florida
Florida is a state in the southeastern United States, located on the nation's Atlantic and Gulf coasts. It is bordered to the west by the Gulf of Mexico, to the north by Alabama and Georgia and to the east by the Atlantic Ocean. With a population of 18,801,310 as measured by the 2010 census, it...

, Louisiana
Louisiana
Louisiana is a state located in the southern region of the United States of America. Its capital is Baton Rouge and largest city is New Orleans. Louisiana is the only state in the U.S. with political subdivisions termed parishes, which are local governments equivalent to counties...

 and Newfoundland.

Anna's hummingbirds are the only hummingbirds to spend the winter in northern climates; they are able to do this as there are enough winter flowers and food to support them. During cold temperatures, Anna's Hummingbirds gradually gain weight during the day as they convert sugar to fat. In addition, hummingbirds with inadequate stores of body fat or insufficient plumage are able to survive periods of sub-freezing weather by lowering their metabolic rate and entering a state of torpor
Torpor
Torpor, sometimes called temporary hibernation is a state of decreased physiological activity in an animal, usually characterized by a reduced body temperature and rate of metabolism. Animals that go through torpor include birds and some mammals such as mice and bats...

.

There are an estimated 1.5 million Anna's Hummingbirds. Their population appears to be stable, and they are not considered an endangered species.

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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