Hummingbirds

Hummingbirds

Hummingbirds are unique for their agility in flight, extremely brilliant Iridescent plumage, long bills, and generally small size. To many Europeans, they first became known as decorative objects on the ornate hats worn by women in the 19th century. When many thousands were imported for this purpose. This unhappy relationship between humans and hum-kingbirds has long since ceased.

Most hummingbirds are immediately recognizable by their small size, long thin bills, brilliant plumage, and ability to hover. Nearly all these characteristics are adaptations for securing their main nourish-mint: nectar.

The hummingbirds’ long bill enables them to reach the nectar inside flowers; in addition, they have long extendable tube-like tongues up which the nectar is drawn. Neck-tar is usually extracted while the hummingbird hovers in front of the flower: it hovers forward while inserting its bill and back-wards when removing it.

This ability to hover forwards and backward is unique among birds and the structure of the hummingbird’s wings differs from that of all other birds except their closest relatives, the swifts. The hummingbird’s wing consists mainly of elongated “hand” bones to which the flight feathers are attached, and the whole wing can rotate as a wrist does. In flight, a hummingbird’s wing is only visible as a blur, because of the speed of its wing beat, between 22 and 78 beats per second, with the highest rate in the smaller species.

Hummingbirds’ feet and legs are peculiarly small because in most species they are used only for perching. The exceptional species are a few that live in the high Andes, the Bearded helmet crest, the hornbills, and the Andean hill star, all of which occasionally walk about, gleaning insects off the bare ground and rock, and have relatively larger legs and feet.

The bills of hummingbirds vary greatly in length and shape, according to the flower sat which they feed. The hermits, which inhabit the tropical and subtropical forests, all have long, slightly curved bills (except for two species with long straight bills), the degree of curvature matching the shape of the flowers at which they feed. The mostly smaller emeralds have straight bills vary-in between 1.8-2.5cm (1in). The hornbills, living in the temperate Andes, have short bills of o.8cm (and take many insects. The sharp. Strong, medium-length bills of the two fairy hummingbirds are used to pierce the corollas of flowers and steal the nectar. The Fiery-tailed awl bill
And the Mountain avocet bill has bills that curve upwards, presumably to match some flower corolla, but this has not yet been investigated. Hummingbird plumage is extremely varied, but in general green, usually, a glittering green, is a common color for the upper parts, while the underparts are often paler, particularly in females.

In about a third of the family, the sexes are alike: these include most of the larger duller hummingbirds such as hermits, saber wings, and Incas, but also the brilliant violetears. Emeralds and others. In the remainder of the family, the sexes are dif-ferment, as males have many adornments that females lack, such as ear tufts, crests, and greatly elongated tails. Many males have patches of brilliant iridescent feathers, usually on the crown, throat, or upper breast; these are most often green, blue, or purple, but also red or yellow.

The majority of hummingbird species occur in Central and South America with the greatest diversity within the latitudeso°to r o°of the equator. In this broad latitudinal belt, as one passes from near sea level in the tropical Amazon forests up the slopes of the Andes through subtropical and temperate zones to the open hush and grass-lands of the paramour, a different assemblage of up to 20 hummingbird species is founding each altitudinal belt until the paramo, which supports around five species. In the temperate latitudes of Chile and Argentina, there is only one species of a hummingbird to be found. The Green-hacked fire crown.

North of Mexico, r 3 species of hummingbirds breed, the number decreasing from the southwest to the northwest of the subcontinent. All these hummingbirds migrate south to winter in Mexico or Central America, except for Anna’s, Costa’s, and the Blue-throated hummingbirds, some individuals of which remain in the southernism while others migrate.

Some hummingbirds have an extremely wide distribution, such as the tropical Black-throated mango, found from Panama to Paraguay; others have a very restricted range, such as the Marvelous spatuletail —known only from one valley in the Andes of Peru. Two new species of hummingbirds, with very restricted ranges, have been discovered in Peru in the 197os, a subangular subtropical levels and a metal tail at temperate levels.

Hummingbirds feed mainly on nectar taken directly from flowers, but all species that have been studied also take small insects.

Within the hummingbird family, two major strategies for nectar feeding are employed. A large number of species with medium-length bills defend from other hummingbirds with a dense patch of flowers capable of supplying most of an individual’s nectar needs. The defended flowers may or may not be exploitable by insects, and are usually produced by trees or shrubs and her-bateau plants growing in the open and receiving full sunlight. These plants typically have relatively brief but intense flower-in periods, so the territory holder must periodically abandon one nectar territory and take up a new one.

Emeralds. Pufflegs.  sun angels and sunbeams are some of the many territorial hummingbirds the other main nectar-feeding strategy is icon-territorial and have been termed “trap-lining.” This term is borrowed from the human trapper who sets traps over a wide area which is then periodically visited. Trap-lining hummingbirds have long bills and the flowers they visit have evolved characteristics that make their nectar available only to long-billed hummingbirds and not to insects or short-billed hummingbirds.

This type of flower is usually produced by bovines, epiphytes (plants that grow another plant), understory trees, and herbaceous plants of the forest and shady areas. Typically, these plants have a long flowering season and produce a few flowers at a time, so providing a long-term food source frothier hummingbirds. Typical trap-lining hummingbirds arc the hermits, the sword-bills, and some Incas.

In addition to these two major feeding strategies, there are also small trap-lining hummingbirds with shorter bills, which feed at small dispersed patches of unspecialized flowers.

Hummingbirds catch their animal food by either hawking for flying insects or by glean-in resting insects or small spiders from the vegetation or spiders’ webs. Most straight-billed hummingbirds use both methods; butte curve-billed hermits catch most of their insects and spiders by picking them off the tips. Edges and undersides of leaves.

Because hummingbirds are so small they need a high intake of food to maintain their body temperature. Particularly at night. Food intake varies with temperature adaptability but typically a hummingbird takes over half its body weight in food a day. If the hnrnminabird needs to conserve its energy it becomes torpid at night.

The breeding seasons of hummingbirds are dossier tied to the flowering seasons of their major nectar sources_ in temperate latitudes, this corresponds to the northern and southern Trines- in arid areas. The rain which stimulates plant growth may be more important than the length of the day. Thus in California, Anna’s hummingbird breeds from November to March. The main rainy season. In high-rainfall areas of the tropics and sub-tropics such as Trinidad and Costa Rica. Hummingbirds start nesting at the end of the wet season and the beginning of the dry season when many trees and shrubs flower: but they also continue breeding into the following wet season when many rich herbaceous plants flower.

As sexes only come together to mate males must announce their presence to females effectively. Hence the congregation of males into leeks or singing assemblies, and the use of the same areas of forest as leeks for many years. Female hummingbirds visit several males at ale and probably make several visits to the leek before selecting a mate. Mating takes place on the leek perch and also occasionally nearby.

Although mating has been observed infrequently, the males of the four species of hermit frequently “false mate” with leaves near their leek perches, performing the same display to the selected leaf before mounting it, as they perform to females.

Most hummingbird songs are very simple, high-pitched, and unmelodious to our ears. The more elaborate and attractive songs, such as that of the barb throats, are warbles lasting 4-5 seconds. Many songs are just repeated single notes, each lasting only quarter of a second.

Despite the simplicity of the song, careful analysis has shown that it varies between leeks or singing assemblies, and even between groups of males within the lek. Young males joining a leek copy the song type of the males near whom they settle.

Only the female hummingbird builds the thinnest, incubates the eggs, and feeds the young. In all but three or four species, male hummingbirds do not even know the whereabouts of nests. Most hummingbirds
Nests are small open cups fixed by cobwebs astride a twig. Although small, the cups are deep and have relatively thick walls of moss lined with vegetables to assist the female in keeping the eggs and small young warm. Hermit hummingbirds build hanging nests attached by cobwebs to the underside of large leaves such as palms and ferns. Some hill stars, metal tails, and lancebillsbuild hanging nests attached by cobwebs to the ceilings of caves, shafts, or rocky overhangs.

Occasionally, two females lay in the sameness. This has been recorded among barb-throats and Rufus-breasted hermits, but there are no records of more than two young surviving from these double clutches. The nestlings are fed by regurgitation. Usually while hovering. The mother inserts her bill into the nestling’s throat and pumps in neck tar and insects.

After leaving the nest the fledgling hum-kingbird is fed by its mother for as long as 20-40 days. A second nesting attempt is usual and a third is not uncommon in the long tropical breeding season. A successful nest may be used again when refurbished or a new one built nearby.

Where the sexes are different, most young hummingbirds fledge into the female plumage, but in a few, such as the Mountain gem, males fledge directly into male plumage. Males who fledge into female plumage acquire their adult plumage at 2—0 months after fledging. Young male hum-kingbirds start to sing, either alone or at the edges of singing assemblies, a few months after independence. Females probably make their first attempt to nest when about one year old. In captivity, hummingbirds live for about job years. In the wild, a blue-chested hummingbird (identified by its unique song) lived for 7 years.

Most hummingbirds inhabiting humid tropical and subtropical areas, where there are no seasonal extremes, are resident all year round, making only short local move-mints when foraging. But in areas where latitude, altitude, or drought cause a dearth of flowers at certain times of year seasonal migrations are undertaken. Thus in the highlands of Costa Rica at 3,000m (almost 0,000ft) four species breed but only one is present throughout the year. Anna’s hum-kingbird, which breeds in winter and early spring in California and adjacent areas. Moves in midsummer high into the moon trains, away from the heat and the drought of the lower country.

The first human threat to the survival of hummingbirds came in the 19th century.
When stuffed hummingbirds became desirable decorations on women’s hats. During this period, as many as 400,00o skins were being imported in a single year by one London dealer, and the dealers in Paris and New York were equally active. Although most of these skins were destined for a short life on a hat, others were bought by natural-its collectors and museums. There are six species of hummingbirds now in museums that are known only from these trade skins: three from Colombia, two from Brazil anode from Bolivia.

Whether they are extinct or not remains to be seen: some are believed to be hybrids and not true species. The fact that new species of hummingbirds have been discovered within the last 10 years suggests that some of these six “extinct” species may yet be found. The main threat to the survival of hummingbirds now comes from the destruction of forests and the replacement of other natural vegetation with crops.

The species of hummingbirds most threatened are the larger hummingbirds with long specialized bills that need the flowers with which they have coevolved to survive. The smaller hummingbirds, which. Are mainly territorial and less specialized, and can adapt to feed on many garden and wayside flowers or second-growth shrubs.

These are the species that learn to come to feeders put out by people. These feeders, containing sugary solutions accessible only through an arrow tube, are put out by many people in North America and by a few in Central and South America. Originally, the feeder tube was surrounded by an artificial flower. But soon such enticement proved unnecessary and hummingbirds came to undecorated feeders, and the territorial species even set up feeding territories based on them.

The provision of suitable nest sites and nest materials is also crucial if hummingbirds are to continue to live in man’s altered environment. For the hanging nest of the hermit hummingbirds. A suitable tapering leaf. Such as the tip of a palm leaf, is essential. And the nest site must be low off the ground. As nests in higher sites are liable to be overturned by the wind.
Of the nest materials. The soft down from seeds or furry leaves is essential for most species but may be missing from some man-made habitats. Building hummingbirds very often reuse such downy material from oldness, which suggests that it is relatively rare and could be a limiting factor. Finally. Hummingbirds must have a plentiful supply of cobwebs, which are used in the nests of offal species