Temporal range: Lower Eocene to Recent
|House sparrow (Passer domesticus)|
|Roughly 100 families, around 5,400 species|
The passerines have a number of adaptations which, taken together, have made them highly successful, with many species round the world.
- The use of song for communication. This is the most obvious adaptation.
- Perching. All passerines have four toes on each foot. Three of the toes point forwards. The other toe points backwards. This means that passerines can easily hold onto trees or rocks. Because of this, they are also known as perching birds. A tendon in the rear of the leg makes the foot curl and grip when the bird lands on a branch. This is more than just a convenience for the birds: it is a locking mechanism so they can sleep without falling off.
- All passerine chicks (babies) are born in an undeveloped state: they need parental help. Their eyes are closed, and they are bald, with little or no down. They cannot leave the nest, and must be fed by the parents. The advantage of this is that their brains grow larger during the fledgling stage. In birds which leave the nest early, their brains depend mainly on material in the egg. Passerines have significantly large brains compared to body size, and many passerines are comparatively intelligent.
- All passerines have 12 tail feathers. This is a basal trait, a feature inherited from their past. It leads biologists to think this large group originally had one common ancestor.
Evidence on their evolution comes from comparative anatomy, the fossil record and molecular biology. It is thought that the first passerines evolved in the southern continent of Gondwana in the Palaeogene, maybe around the Upper Palaeocene some 60–55 mya.
The early fossil record is poor because the first Passeriformes were on the small side, and their delicate bones did not preserve well. Two specimens from Queensland, Australia are fossil bone fragments clearly recognizable as passeriform. They are two species of about 10 and 20 cm in overall length. This proves that some 55 mya, barely into the early Eocene, early perching birds were recognizably distinct. It also suggests that the origin of this great order of birds was in the southern continent.
Most passerines are smaller than typical members of other avian orders. The heaviest and altogether largest passerines are the thick-billed raven and the larger races of common raven, each exceeding 1.5 kg (3.3 lb) and 70 cm (28 in). The superb lyrebird and some birds-of-paradise, due to very long tails or tail coverts, are longer overall. The smallest passerine is the short-tailed pygmy tyrant, at 6.5 cm (2.6 in) and 4.2 g (0.15 oz).
Eggs and nests
The chicks of passerines are altricial: blind, featherless, and helpless when hatched from their eggs. Hence, the chicks require extensive parental care. Most passerines lay coloured eggs, in contrast with nonpasserines, most of whose eggs are white except in some ground-nesting groups such as Charadriiformes and nightjars, where camouflage is necessary, and in some parasitic cuckoos, which match the passerine host's egg. Vinous-throated parrotbill has two egg colours, white and blue. This can prevent the brood parasitic Common cuckoo.
Clutches vary considerably in size: some larger passerines of Australia such as lyrebirds and scrub-robins lay only a single egg, most smaller passerines in warmer climates lay between two and five, while in the higher latitudes of the Northern Hemisphere, hole-nesting species like tits can lay up to a dozen and other species around five or six. The family Viduidae do not build their own nests, instead, they lay eggs in other birds' nests.
There are three sub-orders: Acanthisitti, Tyranni and Passeri. There are only two bird species in the sub-order Acanthisitti. They are known as New Zealand wrens. The sub-order Tyranni are also known as the suboscines. Many of these birds are found in tropical areas. The sub-order Passeri has the most bird species. They are also known as the oscines. They have the best songs of all birds.
- Acanthisittidae: New Zealand "wrens"
- Infraorder Eurylaimides broadbills and allies
- Infraorder Tyrannides - New World suboscines
Songbirds or oscines
- Basal Passeri – the oldest 'true' song birds. They live in Australia.
- Superfamily Meliphagoidea – mainly insectivores and nectarivores, distribution centered on Australo-Melanesian region extending into surroundings, notably the Pacific.
- Superfamily Corvida – a highly diverse group of global distribution, but most plentiful in the Australasian region and surroundings. The oldest truly globally successful group of passerines, they include among them what may well be the most intelligent and the most spectacular of the order.
- Melanocharitidae: berrypeckers and longbills.
- Callaeidae: New Zealand wattlebirds
- Cnemophilidae: satinbirds
- Neosittidae: sittellas
- Vireonidae: vireos
- Campephagidae: cuckoo-shrikes and trillers
- Pachycephalidae: whistlers and allies
- Oriolidae: orioles and Figbirds
- Paramythiidae: Tit Berrypecker and Crested Berrypecker.
- Artamidae: woodswallows, butcherbirds, currawongs and Australian Magpie
- Malaconotidae: puffback shrikes, bush shrikes, tchagras and boubous
- Platysteiridae: wattle-eyes
- Aegithinidae: ioras
- Pityriaseidae: Bornean Bristlehead.
- Prionopidae: helmetshrikes and woodshrikes
- Vangidae: vangas
- Dicruridae: drongos
- Monarchidae: monarch flycatchers
- Rhipiduridae: fantails
- Paradisaeidae: birds of paradise
- Corcoracidae: White-winged Chough and Apostlebird
- Laniidae: shrikes
- Corvidae: crows, ravens and jays
- Corvoidea (?)
- Ptilonorhynchoidea: Bowerbirds and Australian treecreepers
- Logrunners and pseudo-babblers
- Petroicidae: Australian robins
- Rockfowl, rock-jumpers and rail-babblers
- Regulidae: kinglets
- Irenidae: fairy-bluebirds.
- Chloropseidae: leafbirds
- Superfamily Sylvioidea – mostly insectivores, distribution centered on the Indo-Pacific region. Few occur in the Australian region and fewer still in the Americas. Usually sleek and drab birds, few have pronounced sexual dimorphism.
- Alaudidae: larks
- Hirundinidae: swallows and martins
- Phylloscopidae: leaf-warblers and allies.
- Aegithalidae: long-tailed tits or bushtits
- Cettiidae: ground-warblers and allies
- Megaluridae: grass-warblers and allies
- "Bernieridae": Malagasy warblers. A new family.
- Acrocephalidae: marsh- and tree-warblers
- Pycnonotidae: bulbuls
- Cisticolidae: cisticolas and allies
- Sylviidae: "true warblers" and parrotbills.
- Zosteropidae: white-eyes
- Timaliidae: (Old World) babblers.
- Sylvioidea (?)
- Superfamily Muscicapoidea – mostly insectivores, near-global distribution centered on Old World tropics. One family endemic to Americas. Nearly absent (except introductions) from the Australian region. Usually rather stocky for their size, most are quite dark and dull though Sturnidae are commonly iridescent and/or colorful. Sexual dimorphism often absent, sometimes pronounced.
- Superfamily Certhioidea - wrens and allies
- Superfamily Passeroidea – mostly herbivores including many seed-eaters, near-global distribution centered on Palearctic and Americas. Includes the Nine-primaried oscines (probably a subclade). A very high proportion of colorful and highly sexually dimorphic forms.
- Passeridae: true sparrows
- Prunellidae: accentors
- Motacillidae: wagtails and pipits
- Urocynchramidae: Przewalski's Finch
- Estrildidae: estrildid finches (waxbills, munias, etc.)
- Ploceidae: weavers
- Viduidae: indigobirds and whydahs
- Nine-primaried oscines:
- Coerebidae: Bananaquit
- Passerida: (?)
- Panurus: Bearded Reedling ("Bearded "Tit")
- Paroidea: titmice and allies
- Paridae: tits, chickadees and titmice
- Remizidae: penduline tits
- Stenostiridae: stenostirids ("flycatcher-tits")
- "Bombycilloidea" – waxwings and allies
- Bombycillidae: waxwings
- Dulidae: Palmchat
- Ptilogonatidae: silky flycatchers
- Hypocoliidae: Hypocolius
- "Dicaeoidea" – sunbirds and flowerpeckers
- Nectariniidae: sunbirds
- Dicaeidae: flowerpeckers
- Promeropidae: sugarbirds
Images for kids
Passerine Facts for Kids. Kiddle Encyclopedia.