Nectariniidae or sunbirds and spiderhunters, is a family of passerines. They are small, slender passerines from Old World, with long, usually decurved bill and some species with long tail; many brightly colored, most with some iridescence, particularly in male. They are living from Africa to Australia, across Madagascar, Egypt, Iran, Yemen, Southern China, Indian subcontinent, Indochinese peninsulas, Philippines, Southeast Asian to nearby Pacific Islands and just reaches northern Australia. The number of species is greater in equatorial and tropical areas.
Most sunbirds feed largely on nectar, but also take insects and spiders, especially when feeding young. Flower tubes that bar access to nectar because of their shape, are simply punctured at the base near the nectaries. Fruit is also part of the diet of some species. Their flight is fast and direct on their short wings.
The sunbirds have counterparts in two very distantly related groups: the hummingbirds of the Americas and the honeyeaters of Australia. The resemblances are due to convergent evolution brought about by a similar nectar-feeding lifestyle. Some sunbird species can take nectar by hovering like a hummingbird, but they usually perch to feed.
The family ranges in size from the 5-gram black-bellied sunbird to the spectacled spiderhunter, at about 45 grams. Like the hummingbirds, sunbirds are strongly sexually dimorphic, with the males usually brilliantly plumaged in iridescent colours. In addition to this the tails of many species are longer in the males, and overall the males are larger. Sunbirds have long thin down-curved bills and brush-tipped tubular tongues, both adaptations to their nectar feeding. The spiderhunters, of the genus Arachnothera, are distinct in appearance from the other members of the family. They are typically larger than the other sunbirds, with drab brown plumage that is the same for both sexes, and long, down-curved beaks.
In metabolic behaviour similar to that of Andes hummingbirds, species of sunbirds that live at high altitudes or latitudes will enter torpor while roosting at night, lowering their body temperature and entering a state of low activity and responsiveness.
Distribution and Habitat
Sunbirds are a tropical Old World family, with representatives in Africa, Asia and Australasia. In Africa they are found mostly in sub-Saharan Africa and Madagascar but are also distributed in Egypt. In Asia the group occurs along the coasts of the Red Sea as far north as Israel, with a gap in their distribution till Iran, from where the group occurs continuously as far as southern China and Indonesia. In Australasia the family occurs in New Guinea, north eastern Australia and the Solomon Islands. They are generally not found on oceanic islands, with the exception of the Seychelles. The greatest variety of species is found in Africa, where the group probably arose. Most species are sedentary or short-distance seasonal migrants. Sunbirds occur over the entire family's range, whereas the spiderhunters are restricted to Asia.
The sunbirds and spiderhunters occupy a wide range of habitats, with a majority of species being found in primary rainforest, but other habitats used by the family including disturbed secondary forest, open woodland, open scrub and savannah, coastal scrub and alpine forest. Some species have readily adapted to human modified landscapes such as plantations, gardens and agricultural land. Many species are able to occupy a wide range of habitats from sea level to 4900 m.
Behaviour and ecology
Many sunbirds are known to defend feeding and breeding territories; males will sing from prominent perch and chase intruders, including those of other species. The moulting regimes of sunbirds are complex, being different in different species. Sunbirds of the African lowland rain forest have no eclipse plumage, and may nest at any time of the year. However, in the savanna bordering equatorial forest, some species do show duller plumage in the off-season. In the dry months of June−August, male Copper Sunbirds Cinnyris cupreus and Variable Sunbirds C. venustus lose much of their metallic sheen. Post-mating loss of breeding plumage in male Purple Sunbirds is probably the only moult strategy that would allow the species to exploit the November−January period by breeding when most plants are in bloom, the period beforehand being concerned with display and courtship,when breeding plumage is essential to attract a mate. The energetics of the Iranian population clearly favour the males undergoing a partial moult while the females alone build nests and incubate eggs.
Sunbird are active diurnal birds that generally occur in pairs or occasionally in small family groups. A few species occasionally gather in larger groups, and sunbird will join with other birds to mob potential predators, although sunbirds will also aggressively target other species, even if they are not predators, when defending their territories.
Several sunbird and sugarbird species breed in winter when most flowers are out, but when it is colder. The Purple Sunbirds in no Tropical or Ecuatorial areas synchronize their breeding activities with the time when the largest number of flowers are available.
A sunbird that breed outside of the equatorial regions are mostly seasonal breeders, with the majority of these species breeding in the wet season. This timing reflects the increased availability of insect prey for the growing young. Where species, like the buff-throated sunbird, breed in the dry season, it is thought to be associated with the flowering of favoured food plants. Species of sunbird in the equatorial areas breed throughout the year. They are generally monogamous and often territorial, although a few species of sunbirds have lekking behaviour.
The nests of sunbirds are generally purse-shaped, enclosed, suspended from thin branches with generous use of spiderweb. The nests of the spiderhunters are different, both from the sunbirds and in some cases from each other. Some, like the little spiderhunter, are small woven cups attached to the underside of large leaves; that of the yellow-eared spiderhunter is similarly attached but is a long tube. The nests of spiderhunters are inconspicuous, in contrast to those of the other sunbirds which are more visible. In most species the female alone constructs the nest. Up to four eggs are laid. The female builds the nest and incubates the eggs alone, although the male assists in rearing the nestlings. In the spiderhunters both sexes help to incubate the eggs. The nests of sunbirds and spiderhunters are often targeted by brood parasites such as cuckoos and honeyguides.
Relationship with Humans
Overall the family has fared better than many others, with only seven species considered to be threatened with extinction. Most species are fairly resistant to changes in habitat, and while attractive the family is not sought after by the cagebird trade, as they have what is considered an unpleasant song and are tricky to keep alive. Sunbirds are considered attractive birds and readily enter gardens where flowering plants are planted to attract them. There are a few negative interactions, for example the scarlet-chested sunbird is considered a pest in cocoa plantations as it spreads parasitic mistletoes.
Taxonomy and Systematics
Genus: Chalcoparia (sometimes included in Anthreptes) Ruby-cheeked Sunbird (Gmelin, 1788) (Chalcoparia singalensis) Genus: Deleornis (sometimes included in Anthreptes) Grey-headed Sunbird (Reichenow, 1893) (Deleornis axillaris) (sometimes included in Deleornis fraseri) Fraser's Sunbird (Jardine & Selby, 1843) (Deleornis fraseri) Genus: Anthreptes Anchieta's Sunbird (Barboza du Bocage, 1878) (Anthreptes anchietae) Violet-tailed Sunbird (Verreaux & Verreaux, 1851) (Anthreptes aurantius) Mangrove Sunbird (Hartlaub, 1861) (Anthreptes gabonicus) Grey-throated Sunbird (Tweeddale, 1878) (Anthreptes griseigularis) Western Violet-backed Sunbird (Lesson, 1831) (Anthreptes longuemarei) Brown-throated Sunbird (Scopoli, 1786) (Anthreptes malacensis) Uluguru Violet-backed Sunbird (Neumann, 1922) (Anthreptes neglectus) Eastern Violet-backed Sunbird (Hartlaub, 1880) (Anthreptes orientalis) Grey-chinned Sunbird (Shaw, 1812) (Anthreptes rectirostris) Red-throated Sunbird (Shelley, 1878) (Anthreptes rhodolaemus) Banded Green Sunbird (Reichenow, 1905) (Anthreptes rubritorques) Little Green Sunbird (Ogilvie-Grant, 1908) (Anthreptes seimundi) Plain Sunbird (Müller, 1843) (Anthreptes simplex) Genus Hedydipna (sometimes included in Anthreptes) Collared Sunbird (Vieillot, 1819) (Hedydipna collaris) Nile Valley Sunbird (Lichtenstein, 1823) (Hedydipna metallica) Amani Sunbird (Sclater & Moreau, 1935) (Hedydipna pallidigaster) Pygmy Sunbird (Vieillot, 1819) (Hedydipna platura) Genus: Hypogramma Purple-naped Sunbird (Müller, 1843) (Hypogramma hypogrammicum) Genus: Anabathmis (sometimes included in Nectarinia) Newton's Sunbird (Barboza du Bocage, 1887) (Anabathmis newtonii) Principe Sungbird (Hartlaub, 1857) (Anabathmis hartlaubii) Reichenbach's Sunbird (Hartlaub, 1857) (Anabathmis reichenbachii) Genus: Dreptes (sometimes included in Nectarinia) Giant Sunbird (Barboza du Bocage, 1889) (Dreptes thomensis) Genus: Anthobaphes (sometimes included in Nectarinia) Orange-breasted Sunbird (Linnaeus, 1766) (Anthobaphes violacea) Genus: Cyanomitra (sometimes included in Nectarinia) Blue-headed Sunbird (Jackson, 1904) (Cyanomitra alinae) Bannerman's Sunbird (C. H. B. Grant & Mackworth-Praed, 1943) (Cyanomitra bannermani) Bates's Sunbird (Ogilvie-Grant, 1908) (Cinnyris batesi) Copper Sunbird (Shaw, 1812) (Cinnyris cupreus) Blue-throated Brown Sunbird (Jardine & Fraser, 1851) (Cyanomitra cyanolaema) Olive Sunbird (Smith, 1840) (Cyanomitra olivacea) Cameroon Sunbird (Reichenow, 1892) (Cyanomitra oritis) Grey Sunbird (Smith, 1831) (Cyanomitra veroxii) Green-headed Sunbird (Latham, 1790) (Cyanomitra verticalis) Genus: Chalcomitra (sometimes included in Nectarinia) Buff-throated Sunbird (Gervais, 1834) (Chalcomitra adelberti) Amethyst Sunbird (Shaw, 1812) (Chalcomitra amethystina) Socotra Sunbird (Sclater and Hartlaub, 1881) (Chalcomitra balfouri) Carmelite Sunbird (Bechstein, 1811) (Chalcomitra fuliginosa) Hunter's Sunbird (Shelley, 1889) (Chalcomitra hunteri) Green-throated Sunbird (Vieillot, 1819) (Chalcomitra rubescens) Scarlet-chested Sunbird (Linnaeus, 1766) (Chalcomitra senegalensis) Genus: Leptocoma (sometimes included in Nectarinia) Van Hasselt's Sunbird (J. F. Gmelin, 1788) (Leptocoma brasiliana) Copper-throated Sunbird (Jardine, 1842) (Leptocoma calcostetha) Crimson-backed Sunbird (Sykes, 1832)) (Leptocoma minima) Purple-throated Sunbird (Linnaeus, 1766) (Leptocoma sperata) Purple-rumped Sunbird (Linnaeus, 1766) (Leptocoma zeylonica) Black Sunbird (Lesson, 1827) (Leptocoma sericea - formerly Nectarinia aspasia) Genus: Nectarinia (6 species in the strict sense) Bocage's Sunbird (Shelley, 1879) (Nectarinia bocagii) Malachite Sunbird (Linnaeus, 1766) (Nectarinia famosa) Scarlet-tufted Sunbird (Shelley, 1885) (Nectarinia johnstoni) Bronzy Sunbird (Shelley, 1884) (Nectarinia kilimensis) Purple-breasted Sunbird (Reichenow, 1893) (Nectarinia purpureiventris) Tacazze Sunbird (Stanley, 1814) (Nectarinia tacazze) Genus: Drepanorhynchus (sometimes included in Nectarinia) Golden-winged Sunbird (Fischer, 1884) (Drepanorhynchus reichenowi) Genus: Cinnyris (sometimes included in Nectarinia) Greater Double-collared Sunbird (Linnaeus, 1766) (Cinnyris afer) Purple Sunbird (Latham, 1790) (Cinnyris asiaticus) Purple-banded Sunbird (Shaw, 1812) (Cinnyris bifasciatus) Orange-tufted Sunbird (Shelley, 1877) (Cinnyris bouvieri) Apricot-breasted Sunbird (Hartert, 1896) (Cinnyris buettikoferi) Violet-breasted Sunbird (Reichenow, 1905) (Cinnyris chalcomelas) Southern Double-collared Sunbird (Linnaeus, 1766) (Cinnyris chalybeus) Olive-bellied Sunbird (Jardine, 1842) (Cinnyris chloropygius) Splendid Sunbird (Latham, 1801) (Cinnyris coccinigaster) Anjouan Sunbird (Peters, 1864) (Cinnyris comorensis) Congo sunbird (van Oort, 1910) (Cinnyris congensis) Mayotte Sunbird (Hartlaub, 1860) (Cinnyris coquerellii) Seychelles Sunbird (Hartlaub, 1861) (Cinnyris dussumieri) Red-chested Sunbird (Hartlaub, 1857) (Cinnyris erythrocerca) Dusky Sunbird (Vieillot, 1819) (Cinnyris fuscus) Shining Sunbird (Hemprich & Ehrenberg, 1828) (Cinnyris habessinicus) Humblot's Sunbird (Milne-Edwards and Oustalet, 1885) (Cinnyris humbloti) Johanna's Sunbird (Verreaux & Verreaux, 1851) (Cinnyris johannae) Olive-backed Sunbird (Linnaeus, 1766) (Cinnyris jugularis) Loten's Sunbird (Linnaeus, 1766) (Cinnyris lotenius) Loveridge's Sunbird (Hartert, 1922) (Cinnyris loveridgei) Ludwig's Double-collared Sunbird (Bocage, 1868) (Cinnyris ludovicensis) Miombo Double-collared Sunbird (Reichenow, 1907) (Cinnyris manoensis) Marico Sunbird (Smith, 1836) (Cinnyris mariquensis) Eastern Double-collared Sunbird (Shelley, 1885) (Cinnyris mediocris) Tiny Sunbird (Reichenow, 1899) (Cinnyris minullus) Moreau's Sunbird (WL Sclater, 1933) (Cinnyris moreaui) Black-bellied Sunbird (Richmond, 1897) (Cinnyris nectarinioides) Neergaard's Sunbird (C. H. B. Grant, 1908) (Cinnyris neergaardi) Malagasy Green Sunbird (Müller, 1776) (Cinnyris notatus) Palestine Sunbird (Bonaparte, 1856) (Cinnyris oseus) Oustalet's Sunbird (Barboza du Bocage, 1878) (Cinnyris oustaleti) Pemba Sunbird (Reichenow, 1905) (Cinnyris pembae) Prigogine's Double-collared Sunbird (MacDonald, 1958) (Cinnyris prigoginei) Beautiful Sunbird (Linnaeus, 1766) (Cinnyris pulchellus) Regal Sunbird (Reichenow, 1893) (Cinnyris regius) Northern Double-collared Sunbird (Sharpe, 1891) (Cinnyris reichenowi) Rockefeller's Sunbird (Chapin, 1932) (Cinnyris rockefelleri) Rufous-winged Sunbird (Jensen, 1983) Cinnyris rufipennis Shelley's Sunbird (Alexander, 1899)) (Cinnyris shelleyi) Flame-breasted Sunbird (Temminck, 1825) (Cinnyris solaris) Souimanga Sunbird (Gmelin, 1788) (Cinnyris sovimanga) Ruwenzori Double-collared Sunbird (Reichenow, 1893) (Cinnyris stuhlmanni) Superb Sunbird (Shaw, 1812) (Cinnyris superbus) White-bellied Sunbird (Smith, 1836) (Cinnyris talatala) Tsavo Sunbird (van Someren, 1922) (Cinnyris tsavoensis - sometimes included in Cinnyris bifasciatus) Ursula's Sunbird (Alexander, 1903) (Cinnyris ursulae) Variable Sunbird (Shaw, 1799) (Cinnyris venustus) Genus: Aethopyga Handsome Sunbird (Tweeddale, 1877) (Aethopyga belli) Apo Sunbird (Mearns, 1905) (Aethopyga boltoni) Fork-tailed Sunbird (Swinhoe, 1869) (Aethopyga christinae) Elegant Sunbird (Schlegel, 1871) (Aethopyga duyvenbodei) White-flanked Sunbird (Horsfield, 1821) (Aethopyga eximia) Flaming Sunbird (Oustalet, 1876) (Aethopyga flagrans) Mrs. Gould's Sunbird (Vigors, 1831) (Aethopyga gouldiae) Fire-tailed Sunbird (Hodgson, 1837) (Aethopyga ignicauda) Lina's Sunbird (Kennedy, Gonzales & Miranda, 1997) (Aethopyga linaraborae) Javan Sunbird (Temminck, 1822) (Aethopyga mystacalis) Green-tailed Sunbird (Hodgson, 1837) (Aethopyga nipalensis) Grey-hooded Sunbird (Hachisuka, 1941) (Aethopyga primigenia) Metallic-winged Sunbird (Sharpe, 1876) (Aethopyga pulcherrima) Black-throated Sunbird (Hodgson, 1836) (Aethopyga saturata) Lovely Sunbird (Sharpe, 1876) (Aethopyga shelleyi) Crimson Sunbird (Raffles, 1822) (Aethopyga siparaja) Temminck's Sunbird (Müller, 1843) (Aethopyga temminckii) Vigors's Sunbird (Sykes, 1832) (Aethopyga vigorsii) Genus: Arachnothera (spiderhunters) Streaky-breasted Spiderhunter (Horsfield, 1821) (Arachnothera affinis) Yellow-eared Spiderhunter (Temminck, 1826) (Arachnothera chrysogenys) Naked-faced Spiderhunter (Blasius, 1890) (Arachnothera clarae) Thick-billed Spiderhunter (Reichenbach, 1854) (Arachnothera crassirostris) Pale Spiderhunter (Sharpe, 1876) (Arachnothera dilutior) Bornean Spiderhunter (Sharpe, 1893) (Arachnothera everetti) Orange-tufted Spiderhunter (Tweeddale, 1878) (Arachnothera flammifera) Spectacled Spiderhunter (Eyton, 1839) (Arachnothera flavigaster) Whitehead's Spiderhunter (Sharpe, 1897) (Arachnothera juliae) Little Spiderhunter (Latham, 1790) (Arachnothera longirostra) Streaked Sspiderhunter (Hodgson, 1837) (Arachnothera magna) Grey-breasted Spiderhunter (Eyton, 1839) (Arachnothera modesta) Long-billed Spiderhunter (Müller & Schlegel, 1845) (Arachnothera robusta)