Day: February 21, 2014

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Ruby-throated Hummingbird (Archilochus colubris)

by birdinfo • February 21, 2014 • 0 Comments

small animal is the only species of hummingbird that regularly nests east of the Mississippi River in North America.

The Ruby-throated Hummingbird is the smallest bird species that breeds in the Eastern United States and Eastern Canada. This hummingbird is from 7 to 9 cm (2.8 to 3.5 in) long and has a 8 to 11 cm (3.1 to 4.3 in) wingspan. Weight can range from 2 to 6 g (0.071 to 0.212 oz), with males averaging 3.4 g (0.12 oz) against the slightly larger female which averages 3.8 g (0.13 oz).[3][4] Adults are metallic green above and greyish white below, with near-black wings. Their bill, at up to 2 cm (0.79 in), is long, straight and very slender. As in all hummingbirds, the toes and feet of this species are quite small, with a middle toe of around 0.6 cm (0.24 in) and a tarsus of approximately 0.4 cm (0.16 in). The Ruby-throated Hummingbird can only fox-trot if it wants to move along a branch, though it can scratch its head and neck with its feet.

The species is sexually dimorphic. The adult male has a gorget (throat patch) of iridescent ruby red bordered narrowly with velvety black on the upper margin and a forked black tail with a faint violet sheen. The red iridescence is highly directional and appears dull black from many angles. The female has a notched tail with outer feathers banded in green, black, and white and a red throat that may be plain or lightly marked with dusky streaks or stipples. Males are smaller than females and have slightly shorter bills. Juvenile males resemble adult females, though usually with heavier throat markings. The plumage is molted once a year, beginning in late summer.

The breeding habitat is throughout most of eastern North America and the Canadian prairies, in deciduous and pine forests and forest edges, orchards, and gardens. The female builds a nest in a protected location in a shrub or a tree. Of all hummingbirds in the United States, this species has the largest breeding range.

The Ruby-throated Hummingbird is migratory, spending most of the winter in southern Mexico and Central America, as far south as extreme western Panama, and the West Indies. It breeds throughout the eastern United States, east of the 100th meridian, and in southern Canada in eastern and mixed deciduous forest. In winter, it is seen mostly in Mexico.

Ruby-throated Hummingbirds are solitary. Adults of this species are not social, other than during courtship (which lasts a few minutes); the female also cares for her offspring. Both males and females of any age are aggressive towards other hummingbirds. They may defend territories, such as a feeding territory, attacking and chasing other hummingbirds that enter.

As part of their spring migration, portions of the population fly across the Gulf of Mexico. This feat is impressive, as a 800 km (500 mi), non-stop flight over water would seemingly require a caloric energy that far exceeds an adult hummingbird’s body weight of 3 g (0.11 oz). However, researchers discovered the tiny birds can double their lean mass in preparation for their Gulf crossing. The additional mass, stored as fat, provides enough energy for the birds to achieve the flight.

They feed frequently while active during the day. When temperatures drop, particularly on cold nights, they may conserve energy by entering hypothermic torpor.

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°, enabling the bird to fly not only forward but fly 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.

Horned Parakeet (Eunymphicus cornutus)

by birdinfo • February 21, 2014 • 0 Comments

The Horned Parakeet (Eunymphicus cornutus), is a species of parrot in the genus Eunymphicus, in the Psittaculidae family. Eunymphicus cornutus is a largely green parakeet endemic to New Caledonia. It is called Horned because it has two black feathers that protrude from the head and have red tips. This parakeet has a yellowish nape with a black and red face and bluish wings and tail. It makes a nasal “kho-khoot” contact call and also makes a wide range of shrieks and chuckles.

The species has a preference for natural forests and laurel forest habitat. The Horned Parakeet lives humid pine forests on New Caledonia, especially when Agathis and Araucaria pines are present. They live in pairs or small flocks and forage for seedsand nuts in the canopy. It nests both on the ground and in trees.

This bird has declined since the 1880s, but it is still found in some range on New Caledonia and recent population estimates believe that there are over 2500 birds left. Eunymphicus cornutus is declining by poaching and habitat destruction. This bird has habitat fragmented into distinct subpopulations. The total population is small, and it is restricted to single subpopulations which is suspected to have declined owing to habitat degradation, and it therefore qualifies as Vulnerable. Eunymphicus cornutus have undergone a decline over the past three generations (from 1988) owing to habitat degradation also predation by invasive species.

Secretary Bird (Sagittarius serpentarius)

by birdinfo • February 21, 2014 • 0 Comments

The Secretarybird or Secretary Bird (Sagittarius serpentarius) is a very large, mostly terrestrial bird of prey. Endemic to Africa, it is usually found in the open grasslands and savannah of the sub-Saharan region. Although a member of the order Accipitriformes, which also includes many other diurnal raptors such as kites, buzzards, vultures, and harriers, it is given its own family, Sagittariidae.

It appears on the coats of arms of Sudan and South Africa.

First described by English illustrator John Frederick Miller in 1779, the Secretarybird was soon assigned to its own genus, Sagittarius, by French naturalist Johann Hermann in his Tabula Affinatum Animalium. It was not until 1935 that the species was moved to its own family, distinct from all other birds of prey—a classification confirmed by molecular systematics.[4] Recent cladistic analysis has shown Sagittariidae to be an older branch of the diurnal birds of prey thanAccipitridae and Falconidae, but a younger divergence than Cathartidae. Sometimes, the enigmatic bird Eremopezus is classified as an early relative of the Secretarybird, though this is quite uncertain as the bird is only known from a few fragmentary body parts such as the legs. The earliest fossils associated with the family are two species from the genus Pelargopappus. The two species, from the Oligocene and Miocene respectively, were not discovered in Africa butFrance. The feet in these fossils are more like those of the Accipitridae; it is suggested that these characteristics are primitive features within the family. In spite of their age, it is not thought that the two species are ancestral to the Secretarybird.

Its common name is popularly thought to derive from the crest of long quill-like feathers, lending the bird the appearance of a secretary with quill pens tucked behind his or her ear, as was once common practice. A more recent hypothesis is that “secretary” is borrowed from a French corruption of the Arabic saqr-et-tair or “hunter-bird.”

The generic name “Sagittarius” is Latin for “archer,” perhaps likening the Secretarybird’s “quills” to a quiver of arrows, and the specific epithet “serpentarius” recalls the bird’s skill as a hunter of reptiles. Alternatively, the name could refer to the last two constellations in the Zodiac, Sagittarius and Serpentarius (now known as Ophiuchus).

The Secretarybird is instantly recognizable as having an eagle-like body on crane-like legs which increases the bird’s height to as much as 1.3 m (4 ft) tall. This bird has an eagle-like head with a hooked bill, but has rounded wings. Body weight can range from 2.3 to 4.5 kg (5.1 to 9.9 lb) and height is 90–130 cm (35–51 in). Total length from 112 to 152 cm (44 to 60 in) and the wingspan is 191–220 cm (75–87 in). The tarsus of the secretarybird averages 31 cm (12 in) and the tail is 57–85 cm (22–33 in), both of which factor into making them both taller and longer than any other species of raptor. The neck is not especially long, and can only be lowered down to the inter-tarsal joint, so birds reaching down to the ground or drinking must stoop to do so.

From a distance or in flight it resembles a crane more than a bird of prey. The tail has two elongated central feathers that extend beyond the feet during flight, as well as long flat plumage creating a posterior crest. Secretarybird flight feathers and thighs are black, while most of the coverts are grey with some being white. Sexes look similar to one another as the species exhibits very little sexual dimorphism, although the male has longer head plumes and tail feathers. Adults have a featherless red face as opposed to the yellow facial skin of the young.Secretarybirds are endemic to Sub-Saharan Africa and are non-migratory, though they may follow food sources. Their range extends from Mauritania to Somalia and south to the Cape of Good Hope. These birds are also found at a variety of elevations, from the coastal plains to the highlands. Secretarybirds prefer open grasslands and savannas rather than forests and dense shrubbery which may impede their cursorial existence. While the birds roost on the localAcacia trees at night, they spend much of the day on the ground, returning to roosting sites just before dark.