太阳鸟科科

它们与蜂鸟有相似的生态栖位，属趋同进化。一些太阳鸟物种可以通过像蜂鸟一样盘旋来获取花蜜。

• 该科包含如下各属：
• 直嘴太阳鸟属 Chalcoparia
• Deleornis
• 食蜜鸟属 Anthreptes
• Hedydipna
• Hypogramma
• Anabathmis
• 巨花蜜鸟属 Dreptes
• 橙胸花蜜鸟属 Anthobaphes
• Cyanomitra
• Chalcomitra
• Leptocoma
• Nectarinia
• 金翅花蜜鸟属 Drepanorhynchus
• 花蜜鸟属 Cinnyris
• 太阳鸟属 Aethopyga
• 捕蛛鸟属 Arachnothera

Sunbirds and spiderhunters make up the family Nectariniidae of passerine birds. They are small, slender passerines from the Old World, usually with downward-curved bills. Many are brightly coloured, often with iridescent feathers, particularly in the males. Many species also have especially long tail feathers. Their range extends through most of Africa to the Middle East, South Asia, South-east Asia and southern China, to Indonesia, New Guinea and northern Australia. Species diversity is highest in equatorial regions.

There are 152 species in 16 genera. Their family name is from most sunbirds feeding largely on nectar, but they will also catch insects and spiders, especially when feeding their young. Flowers that prevent access to their nectar because of their shape (for example, very long and narrow flowers) are simply punctured at the base near the nectaries, from which the birds sip the nectar. Fruit is also part of the diet of some species. Their flight is fast and direct, thanks to 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.

Description

The family ranges in size from the 5 g (0.18 oz) black-bellied sunbird to the spectacled spiderhunter at about 45 g (1.6 oz). 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.

Distribution and habitat

Sunbirds are a tropical Old World family, with representatives in Africa, Asia and Australasia. In Africa, they occur mostly in sub-Saharan Africa and Madagascar and in Egypt. In Asia, the group occurs along the coast of the Red Sea to the Palestine region and along the Mediterranean up to Beirut, with a gap in their distribution across inland Syria and Iraq, and resuming in Iran, from where the group occurs continuously as far as southern China and Indonesia. In Australasia, they occur 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.

Behaviour and ecology

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.

Breeding

Sunbirds that breed outside of the equatorial regions are mostly seasonal breeders, with the majority of them 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.

Relationship with humans

Seven species are considered to be threatened with extinction. Most species are fairly resistant to changes in habitat, and 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.

List of genera

The family contains 152 species divided into 16 genera: For more detail, see list of sunbird species.