Tuesday, November 9, 2010

Flying Jewel invasion

halcyon |ˈhalsēən|

denoting a period of time in the past that was idyllically happy and peaceful : the halcyon days of the mid-1920s , when profits were soaring. See note at calm .

1 a tropical Asian and African kingfisher with brightly colored plumage. Genus Halcyon, family Alcedinidae: many species.
2 a mythical bird said by ancient writers to breed in a nest floating at sea at the winter solstice, charming the wind and waves into calm.
ORIGIN late Middle English (in the mythological sense): via Latin from Greek alkuōn ‘kingfisher’ (also halkuōn, by association with hals ‘sea’ and kuōn ‘conceiving’ ).

Eurasian kingfisher is a vibrant bird, both in looks and behavior. A stab of electric blue contrasted with the warm chestnut orange of the under parts, is the usual image that it presents. And then it is gone, leaving behind the impression of a living cobalt and azure jewel.
Kingfishers are small-to-large, monogamous. More-or-less solitary, bright-plumaged birds of forests, savannas and waterside situations. The great majority of species are tropical, but one or two species from each subfamily have extended as migrant breeders into temperate latitudes.
Primitive species are forest-dwelling predators feeding mainly on forest-floor insects ;more specialized types plunge into shallow water for small animals, fly catch for air-borne insects, forage in leaf-litter for earth-worms, prey on birds and reptiles, and deep-dive for fish from a perch or (particularly the Pied kingfisher) from hovering flight.
Like other birds of their order, kingfishers are large-headed, short-necked, stout-bodied and short-legged, with weak, fleshy feet having the second and third toes partly joined. The bill is straight, strong and long, flattened from top to bottom in insectivorous species and from side to side in fish-eating species. The extraordinary Shovel-billed or Earthworm-eating kingfisher has a short, wide, conical bill. Other forms have the bill sharp-pointed and dagger-like. But in the adult African dwarf kingfisher it is blunt-tipped (sharp in the juvenile). For no obvious reason, several not-closely related lineages of kingfishers are three-toed, having lost the fourth toe. Plumage and other characters show that three-toed species are very closely allied with some four-toed species in the genera Ceyx and Alcedo, and thatthe three-toed kingfishers do not comprise single natural assemblage as they were formerly held to do. Although colorful, the colors are in general muted, with shades of blue and red predominating. Shoulders and rump are usually shining azure blue, and dark cap and back are commonly separated by a white or pale collar. Juveniles of paradise kingfishers are dusky, differing markedly from their adults, but in other species juveniles are bright in plumage, though duller than adults. There is little geographic variation within a species, and color conservatism has led to allied species looking much alike. Notable exceptions are the Variable dwarf kingfisher, whose subspecies on Islands from the Philippines to the Solomon vary from red to blue or yellow, Africa’s Gray-headed kingfisher and the much larger Black-capped kingfisher of China. Although the last two differ in appearance, biochemist-cal and biological characteristics, as well as the geographical relationship of their ranges, suggest very strongly that they are of immediate descent from a common ancestor.
The evolutionary history of other groups of kingfisher species is better understood than for most groups of birds. The family almost certainly arose in tropical rain forest, partly in the northern Australasian region (insectivorous woodland kingfishers, sub-family llaceloninae), and partly in adjacent Indonesia, Borneo and Southeast Asia (forest insectivores, evolving into waterside fishers, subfamily Alcedininae). Both sub-families extended into Asia and repeatedly invaded Africa, on as many as 12 separate occasions ; the Alcedininae invaded the New World to give rise to the Green and Giant kingfishers there (exclusive fishers, sub-family Beryline). The several Pacific archipelago species of woodland (Halcyon) kingfishers have clearly evolved from the wide-ranging complex formed by the Mangrove and Beach kingfishers and the more southerly sacred kingfisher. African mangrove, Woodland and Blue-breasted kingfishers are similarly of recent descent from a single ancestor; their habitats keep them apart, though they are acquiring sufficient ecological differences to permit some degree of geographical overlap. Belted, Ringed. Giant and Crested kingfishers respectively in North America, tropical America, Africa, and southern Asia, are all very closely allied and it is thought that the Giant and Crested descended from small populations of the first two which crossed
The Atlantic (Belted kingfishers occasionally still arrive in Europe as vagrants). Species multiplication is also demonstrated by the four green kingfishers of the neotropics.Long ago, their common ancestor there separated into two geographically distinct populations which duly happened to evolve differences of size, enabling them to overlaps distinct species. Later, each of the two species repeated the separating process, and the result today is four species all occupying much the same range, having body-weights close to the proportions 1:2 :4:8, with the smallest and second-largest (American Pygmy and Green-and-refocus kingfishers)being almost alike in appearance and the largest and second-smallest (Amazon and Green kingfishers) also being remarkably similar.
All fishing kingfishers take a certain amount of invertebrate prey in addition to fish; Eurasian kingfishers, for instance, have about 21 percent of insects in their diet, mainly aquatic but some caught on dry land. Pied kingfishers, fishing from hovering flight more than from a perch, are in that sense at the pinnacle of evolution of the family ; in Africa they live entirely upon fish(hut in India take insects and crabs too, and can even “hawk” for flying termites). Not having to rely on a perch means that they can fish far from shore: on Lake Karina they fish up to 3km (.9mi) offshore at dawn and dusk, catching sardines, a deep-sea fish which rises to the surface at those times. In Natal, 8o percent of their fish food consists of Sarotherodon mossambicus, mainly in ther-2g (o.o35—o7oz) weight class, and on Lake Victoria they prey almost exclusivelyon fish from the general Haplochrornis andLngraulicypris. When they forage close tithe shore, they dive from hovering flight in windy conditions when ruffled water seems to make fishing from a perch unrewarding. Only when the surface is calm do they fish from perches to a greater extent than from hovering. A Pied kingfisher flies low over the water to a desired hunting station, then rises up to Tom (33ft) and hovers on rapidly heating wings with the trunk held almost vertically and the bill pointing acutely down, keeping station for5— o seconds, then diving steeply to penetrate possibly 2/11 (6.5ft) underwater, occasionally catching more than one fish ate time. Similar behavior is exhibited by the belted kingfisher of North America.
Most kingfishers are monogamous and territorial, a pair defending an area of wood-land on a stretch of river against incursion by other birds of the same species. Several species are migratory, both in the temperate zone and within the tropics; others are sedentary. What little is known suggests that most species breed at the end of their first year, and are quite long-lived. Wood-land kingfishers (Halcyon species) have a territorial advertising display, singing loudly and repeatedly from a conspicuous treetop perch, spreading the wings widely, with the patterned undersides facing forwards, and rotating the body about the vertical axis. Other species have little by way of any court-ship display. Both sexes dig the nest tunnel and the male takes a minor role in incubi-hon. The eggs hatch at about daily intervals, in the sequence of laying, so nestlings vary considerably in size. They are fed by both parents equally.
Laughing kookaburras in Australia and Pied kingfishers in Africa have a more com-plea social system than solitary monogamy. Each has adult helpers at the nest, and in Pied kingfishers there are two kinds of helpers: primary helpers (those helping their own parents) and secondary helpers (those helping an unrelated pair). “Helping “includes defense of territory and feeding the young in the nest and after fledging. This species breeds in loose colonies, the only kingfisher to do so.
Kingfishers have not, in general, come into direct conflict with man. As fish-caters few species have occasionally been viewed as pests on fishing streams and dealt with accordingly; but usually they are treated with respect—and often with admiration. Formerly, great numbers of Eurasian king-fishers were shot or netted to make fishing “flies” from their feathers, and in earlier times (in Britain at least) superstition caused the destruction of many, for a dried king-fisher corpse in the house was supposed to avert thunderstorms and keep out moths! Today, man’s harmful effects upon king-fishers are more accidental than deliberate, in the pollution of fresh waters and the modification of habitats, especially rainforest. Bird-catchers destroy many; atfatinga in Assam great numbers of migrating Eurasian, Stork-billed, Ruddy, and Oriental dwarf kingfishers are killed (and presumably eaten) when they are attracted to light beacons around the village at night. In some Mediterranean countries, many kingfishers are killed by netting, shooting and liming, although they are not target species.
Few populations are at great risk. So many species are confined to tropical rainforests, however, or to small Pacific islands or archipelagos, that their fate depends entirely on the preservation of their habit-tats. Almost certainly extinct is the distinctive race of the Tuamotu kingfisher. Which lived until about 1922 on the island ofMangareva, 1,250km (about 800mil fromTuamotu in the central Pacific.

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