Astab of electric blue contrasted with the warm chestnut orange of the underparts – such is the image Europe's Common kingfisher most often presents. And then it is gone, leaving behind the fleeting impression of a living cobalt and azure jewel. If legend is to be believed, the Common kingfisher was once a dull gray bird that acquired its fantastic colors when it left Noah's Ark.
Similar small, brilliant-blue kingfishers live on the other side of the world too, but in addition Australia and New Guinea boast the kookaburras. Large, noisy and much-loved birds of gardens and dry woodlands, kookaburras are quite gregarious in their habits, they live in trees, from which they pounce to the ground for their animal food. New Guinea and adjacent archipelagos have the greatest number of kingfisher species in the greatest diversity of forms, although Africa and south Asia are rich in species too. Other species, nearly all of them colorful and attractive, are to be found in the Americas and on hundreds of islands scattered througout the Pacific Ocean.
Kingfishers are bright-plumaged, monogamous, more or less solitary birds of forests, savannas, and watersides. 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, flycatch for airborne insects, forage in leaf-litter for earthworms, 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 on which the second and third toes are partly joined. The bill is straight, strong, and long, flattened from top to bottom in insectivorous species and from side to side in fish-eaters. The extraordinary Shovel-billed or Earthworm-eating kingfisher of New Guinea has a short, wide, conical bill. Other forms have the bill sharp-pointed and daggerlike, 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 that the three-toed kingfishers do not comprise a single natural assemblage, as they were formerly held to do.
Although kingfishers are colorful, the colors are in general muted, with shades of blue and red predominating. Shoulders and rump are usually a shining azure blue, and a dark cap and back are commonly separated by a white or pale collar. Juveniles of paradise kingfishers are dusky, differing markedly from the adults, but in other species juveniles are bright in plumage, although duller than adults. There is little geographic variation within a species, and evolutionary 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 Solomons 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, biochemical and biological characteristics, as well as the geographical relationship of their ranges, suggest strongly that they are of immediate descent from a common ancestor.
Kingfishers living on dry land are sit-and-wait predators of small animals on the surface of the ground. Those living by water are true fishers. All have very good eyesight, but the fishers have particular problems to overcome, because of light refraction, which makes prey appear to be nearer to the surface of water than they really are, and because of light reflection from rippling or choppy surfaces. Kingfishers have a limited degree of movement of the eyes in their sockets, and make up for it by moving the whole head, fast and flexibly, in order to track rapidly-moving prey. Sacred kingfishers are thought to be able to spot a small prey animal up to 90m (300ft) away. Belted kingfishers are sensitive to near-ultraviolet light, which may also assist in prey detection.
All kingfishers have two foveae in each eye – depressions on the retina with very numerous light-detecting cone cells. Fields of vision overlap to the front, giving binocular vision there, and one of the foveae in each eye looks out into the binocular field; the other looks into the monocular field at each side of the head. Experiments show that the hunting kingfisher instantly detects prey as its image crosses the monocular fovea; then, when the head is angled in the usual manner with the bill pointing down at an angle of about 60°, a slight rotation of the head transfers the image to the binocular fovea in one or both eyes, allowing the prey's distance away to be precisely evaluated. Pied kingfishers can catch a fish 2m (6.5ft) below the surface, the bird achieving that depth by diving vertically from a height of 2–3m (6.5–10ft) above the water. In the split second when a Common kingfisher enters the water surface, it turns its wings backward at the shoulder joint, and a cover of translucent skin, the nictitating membrane, passes over the eye from front to back, protecting it. Shooting down like an arrow, the bird uses its wings as brakes and in the same instant seizes its prey in the ends of its mandibles, retracts its neck, turns its body, and flies up through the water and then the air, often nearly along the same course as its dive.
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 (in the case of the insectivorous woodland kingfishers of the subfamily Daceloninae) and partly in adjacent Indonesia, Borneo, and southeast Asia (forest insectivores, evolving into waterside fishers of the subfamily Alcedininae). Both subfamilies 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 (in addition to the Cerylinae).
The several Pacific archipelago species of woodland (Halcyon and Todiramphus) kingfishers have clearly evolved from the wideranging complex formed by the Collared and Beach kingfishers and the more southerly Sacred kingfisher. Mangrove, Woodland, and Blue-breasted kingfishers are similarly of recent descent from a single ancestor; their habitats keep them apart, although 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 that 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 that duly happened to evolve differences of size, enabling them to overlap as 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 (the American Pygmy kingfisher and the Green-and-rufous kingfisher) being almost alike in appearance, and the largest and second-smallest (Amazon and Green kingfishers) also being remarkably similar.
The end result of all of these ancient and recent historical movements within and between continents and across the oceans is a wealth of diverse kinds in many regions. Temperate zones in the northern tropics do not do so well, and only single species reach as far north as the Gulf of Finland and the western shores of the Sea of Okhotsk (Common kingfisher) and Alaska and Newfoundland (Belted kingfisher). Central and South America possess five, the huge Ringed kingfisher and the four small or medium-sized green kingfishers. Africa and Madagascar have 18 species. From India to Japan and Cambodia 12 species reside, more passing through on migration. The Philippines have 11 species, six of them occurring nowhere else; Malaysia and Indonesia boast another 11 species; and Sulawesi possesses 11 also, of which five are found there alone.
In New Guinea, the Bismarck Archipelago, and Australia's tropical Cape York Peninsula there are 16 woodland kingfishers and kookaburras and three fishing ones. The rest of Australia has six; and Oceania, from the Solomon Islands and New Zealand to Tahiti and the Tuamotu Archipelago, hosts 11 species, seven of them endemic. To single out the smallest of these areas, Sulawesi is home to a variety of kingfishers representing two of the three main groups or subfamilies (families, according to some researchers). Unique to the forests of that island are the Lilac-cheeked, Green-backed, Scaly-breasted, and Sulawesi dwarf kingfishers. Common paradise, Ruddy, Black-capped, Collared, Sacred, Blue-eared, and Common kingfishers inhabit Sulawesi too, each as part of a much more extensive range.
All fishing kingfishers take a certain amount of invertebrate prey in addition to fish; insects, for example, make up about 21 percent of the Common kingfisher's diet; most are aquatic, but some are caught on dry land. Pied kingfishers, fishing from hovering flight more than from a perch, are in that sense at the peak of the family's evolution; in Africa they live entirely upon fish (but 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 Kariba they fish up to 3km (2mi) offshore at dawn and dusk, catching sardines, deep-sea fish that rise to the surface at those times. In Natal, 80 percent of their fish food consists of Sarotherodon mossambicus, mainly in the 1–2g (0.035–0.07oz) weight class, and on Lake Victoria they prey almost exclusively on fish from the genera Haplochromis and Engraulicypris. When foraging close to the shore in windy conditions, they dive from hovering flight, as 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 10m (33ft) above the surface and hovers on rapidly beating wings. With the body held almost vertically and the bill pointing acutely down, the bird keeps station for 5–10 seconds, then dives steeply to penetrate possibly 2m (6.5ft) underwater, occasionally catching more than one fish at a time. The Belted kingfisher of North America behaves in a similar way.
The divide between preying on dry-land animals and aquatic ones is not precise. Sacred kingfishers live in woodland but often hunt from shrubs along ditches and lakeshores. They take a wide range of prey, including insects, spiders, earthworms, mollusks, cructaceans, centipedes, fish, frogs, tadpoles, reptiles, and even small birds or mammals. A study in a single region of the food and foraging relations of South America's five fishing kingfishers showed that fish-eating was proportional to the abundance of fish at the surface near the shoreline, with all types being taken as available; the larger kingfishers perched higher, and presumably dived deeper, and the average prey sizes were in proportion to the birds' different body sizes and bill lengths.
Most kingfishers are monogamous and territorial, a pair defending an area of woodland 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 of their breeding habits suggests that most species breed at the end of their first year, and are quite long-lived. Woodland 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 forward and rotating the body about the vertical axis. Other species have little by way of any courtship display. Both sexes dig the nest tunnel, and the male takes a minor role in incubation. The eggs hatch at about daily intervals, in the same sequence as they were laid, 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 complex social system. Each has adult helpers at the nest, and in Pied kingfishers these are of two kinds: primary helpers (those helping their own parents) and secondary helpers (those helping an unrelated pair). A pair seldom has more than one primary helper but, particularly in places where the food resources are not so good, they usually have several secondary helpers. “Helping” includes defending 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-eaters, a few species have sometimes been viewed as pests on fishing streams and persecuted; but usually they are treated with respect and often with admiration. Formerly, great numbers of Common kingfishers 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 kingfisher corpse in the house was supposed to avert thunderstorms and keep out moths! Today, the harmful effects of humans on kingfishers are more accidental than deliberate, in the pollution of fresh waters and the modification of habitats, especially rain forest. Bird-catchers destroy many; at Jatinga in Assam great numbers of migrating Common, Stork-billed, Ruddy, and Oriental dwarf kingfishers are killed (and presumably eaten) when they are attracted to light beacons around the villages at night. In some Mediterranean countries, many kingfishers are killed by netting, shooting, and liming, although they are not target species.
Few populations of kingfisher are at great risk. However, so many species are confined to tropical rain forests, or to small Pacific islands or archipelagos, that their fate depends largely on the preservation of their habitats. The distinctive race of the Tuamotu kingfisher that lived until about 1922 on the island of Mangareva in the central Pacific is almost certainly extinct; the other race, only found on Niau Island in the Tuamotus, numbers only a few hundred birds and is classed as Vulnerable. The very poorly-known Mustached kingfisher is another endangered bird. It is restricted to hill forest on the islands of Bougainville and Guadalcanal in the Solomons; the total population is estimated at less than 1,000 individuals in all, and perhaps as few as 250.
Kingfishers are famous for their fishing skills, but they have many relatives that live far from rivers and streams. These include bee-eaters,...
Full text Article A Kingfisher Amongst Reeds in Winter, 1901 (pencil and watercolour heightened with white)
Artist: Thorburn Archibald (1860-1935) Location: Private Collection Credit: A Kingfisher Amongst Reeds in Winter, 1901 (pencil and watercolour heigh