Birds are two-legged, warm-blooded, egg-laying vertebrates which have a beak with no teeth, a four-chambered heart, a high metabolic rate, feathers, wings and a lightweight skeleton. These latter adaptions allow most birds to fly. Flight is the primary means of locomotion for most bird species and it distinguishes birds from most other vertebrates. The ability to fly allows birds to allude predators and to search large distances for both food and mates. Flight also allows many bird species to take advantage of global differences in the seasonal climates by migrating from one region to another as the seasons change. Flying has allowed birds to develop survival strategies, often unavailable to other animals so it is not surprising that birds are found in a variety of habitats on all seven of the world’s continents. Some birds have even adapted to live on the world’s oceans or within them, sometimes only coming ashore to breed.
There are approximately 10,000 different species of birds on the earth today. Scientist have classified these bird species into more than 200 different families which in turn are organized into 29 orders of birds. Birds are believed to have evolved from a dinosaur ancestor and are consider the closest living relative of dinosaurs. The fossil evidence suggests the early ancestor of birds may have been arboreal and had the ability to glide. Once the ability to fly evolved, birds, as a group, radiated into many different species occupying a wide range of ecological niches with the highest bird diversity occurring in the tropical regions of the world.
Unfortunately, human activity threatens about 1,200 bird species with extinction. Nearly 200 species of birds have already become extinct due to human activity, many of these flightless birds that were found on islands with no terrestrial predators.
Although flight was an evolutionary advantage for most birds, a few species of birds have actually lost the ability to fly. There seem to be three situations where flightless has tended to evolve. The best example of the first, would be penguins. Living in water made it necessary to trade flying for swimming. Or, to look at it another way, penguins can still fly, they just fly in water instead of air. The second situation where flightless birds seem to evolve is on isolated islands which have no land predators. Other examples of flightless birds are the unusually large birds, notably the Ostrich (Struthio camelus), Cassowary (Casuarius sp.), Emu (Dromaius novaehollandiae) and Rhea (Rhea sp.), where there appears to have been an evolutionary tradeoff of flight for large size.
Birds have a poor sense of smell and mainly rely on their sight and hearing to find food, detect predators and to find mates. Because of its importance for flight, vision is the most important sense in most birds. The most developed parts of the brain, in most birds, are the areas that control the flight-related functions and vision. Birds have both large nervous systems and large eyes relative to their body size. Within the animal kingdom, birds have the largest eyes relative to their size. Some birds can actual perceive ultraviolet light, as they are tetrachromatic, possessing ultraviolet sensitive cone cells in the eye as well as cone cells sensitive to green, red and blue light. In contrast, humans lack this ability since the lens of the human eye blocks most light of that wavelength range and most humans do not have ultraviolet sensitive cone cells. Nocturnal birds have eyes with large corneas relative to the eye’s length which optimizes their visual sensitivity at night. Birds can also detect very slow movement, such as the movement of the sun and the constellations across the sky, which is imperceptible to humans. This ability is believed to be used by migrating birds to orient themselves. Studies have suggested that some migratory birds can detect the earth’s magnetic fields with theirs eyes and also use this information to orient themselves during migrations.
Birds – Aves
Struthioniformes
– Africa and Australasia; 2 species
Struthionidae: Ostrich
Rheiformes
– South America; 2 species
Rheidae: rheas
Tinamiformes
– South America; 45 species
Tinamidae: tinamous
Casuariiformes
– Australasia; 4 species
Casuariidae: cassowaries
Dromaiidae: Emu
Apterygiformes
– Australasia; 5 species
Apterygidae: kiwis
Anseriformes
– Worldwide; 150 species
Anhimidae: screamers
Anseranatidae: Magpie-goose
Anatidae: ducks, geese, and swans
Galliformes
– Worldwide; 250 species
Megapodidae: megapodes
Cracidae: chachalacas, curassows, and guans
Phasianoidea: pheasants and allies
Odontophoridae: New World quail
Numididae: guineafowl
Phasianidae: pheasants and relatives
Podicipediformes
– Worldwide; 19 species; sometimes grouped with Phoenicopteriformes
Podicipedidae: grebes
Phoenicopteriformes
– Worldwide; 6 species
Phoenicopteridae: flamingos
Mesitornithiformes
– Madagascar, Neotropics, New Caledonia; 5 species
Mesitornithidae: mesites
Rhynochetidae: Kagu
Eurypygidae: Sunbittern
Pteroclidiformes
– Africa, Europe, Asia; 16 species; sometimes grouped with Columbiformes
Pteroclididae: sandgrouse
Columbiformes
– Worldwide; 300 species
Columbidae: pigeons and doves
Phaethontiformes
– Oceanic; 3 species
Phaethontidae: tropicbirds
Caprimulgiformes
– Worldwide; 90 species
Steatornithidae: Oilbird
Podargidae: frogmouths
Nyctibiidae: potoos
Caprimulgidae: nighthawks and nightjars
Eurostopodidae: eared-nightjars
Apodiformes
– Worldwide; 400 species
Trochilidae: hummingbirds
Apodidae: swifts
Hemiprocnidae:treeswifts
Aegotheliformes
Oceania; 10 species; sometimes grouped with Apodiformes
Aegothelidae: owlet-nightjars
Cuculiformes
Worldwide; 126 species
Cuculidae: cuckoos and relatives
Opisthocomiformes
– South America; 1 species
Opisthocomidae: Hoatzin
Musophagiformes
– Africa; 23 species
Musophagidae: turacos and relatives
Gruiformes
– Worldwide; 191 species
Otididae: bustards
Grui: cranes and allies
Gruidae: cranes
Aramidae: Limpkin
Psophiidae: trumpeters
Ralli: rails and allies
Rallidae: rails and relatives
Sarothruridae: flufftails
Heliornithidae: finfoots
Gaviiformes
– North America, Eurasia; 5 species
Gaviidae: loons
Sphenisciformes
– Antarctic and southern waters; 17 species
Spheniscidae: penguins
Procellariiformes
– Pan-oceanic; 120 species
Diomedeidae: albatrosses
Procellariidae: petrels and relatives
Pelecanoididae: diving petrels
Hydrobatidae: storm petrels
Ciconiiformes
– Worldwide; 19 species
Ciconiidae: storks
Pelecaniformes
– Worldwide; 108 species
Balaenicipitidae: Shoebill
Scopidae: Hamerkop
Pelecanidae: pelicans
Ardeidae: herons and relatives
Threskiornithidae: ibises and spoonbills
Suliformes
– Worldwide; 59 species
Phalacrocoracidae: cormorants and shags
Fregatidae: frigatebirds
Sulidae: boobies and gannets
Anhingidae: darters
Charadriiformes
– Worldwide; 350 species
Scolopacidae: sandpipers and relatives
Thinocori: jacana-like waders
Rostratulidae: painted snipes
Pluvianidae: Egyptian Plover
Jacanidae: jacanas
Thinocoridae: Seedsnipes
Pedionomidae: Plains-wanderer
Turnicidae: buttonquail
Lari: gulls and allies
Laridae: gulls
Rhynchopidae: skimmers
Sternidae: terns
Alcidae: auks
Stercorariidae: skuas and jaegers
Glareolidae: coursers and pratincoles
Dromadidae: Crab-Plover
Chionidi: thick-knees and allies
Burhinidae: thick-knees and relatives
Chionididae: sheathbills
Pluvianellidae: Magellanic Plover
Ibidorhynchidae: Ibisbill
Recurvirostridae: avocets and stilts
Haematopodidae: oystercatchers
Charadriidae: plovers and lapwings
Accipitriformes
– Worldwide; 200 species
Cathartidae: New World vultures
Pandionidae: Osprey
Accipitridae: hawks, eagles, buzzards, harriers, kites and Old World vultures
Sagittaridae: Secretarybird
Strigiformes
– Worldwide; 130 species
Tytonidae: barn owls
Strigidae: true owls
Coliiformes[edit]
Sub-Saharan Africa; 6 species.
Coliidae: mousebirds
Trogoniformes
Sub-Saharan Africa, Americas, Asia; 35 species.
Trogonidae: trogons and quetzals
Coraciiformes
– Worldwide; 144 species
Meropidae: bee-eaters
Coraciidae: rollers
Brachypteraciidae: ground rollers
Todidae: todies
Momotidae: motmots
Alcedines: kingfishers
Alcedinidae: river kingfishers
Halcyonidae: tree kingfishers
Cerylidae: water kingfishers
Bucerotiformes
= Old World, New Guinea; 64 species
Bucerotidae: hornbills
Upupidae: Hoopoe
Phoeniculidae: woodhoopoes
Leptosomatiformes
– Madagascar; 1 species
Leptosomatidae: Cuckoo-roller
Piciformes
– Worldwide except Australasia; 400 species
Galbulidae: jacamars
Bucconidae: puffbirds
Lybiidae: African barbets
Megalaimidae: Asian barbets
Ramphastidae: toucans
Semnornithidae: Toucan barbets
Capitonidae: American barbets
Picidae: woodpeckers
Indicatoridae: honeyguides
Falconiformes
– Worldwide; 60 species
Falconidae: falcons and relatives
Cariamiformes
– South America; 2 species
Cariamidae: seriemas
Psittaciformes
– Pan-tropical, southern temperate zones; 330 species
Nestoridae: Kea and kakas
Strigopidae: Kakapo
Cacatuidae: cockatoos
Psittacidae: African and American parrots
Psittrichasiidae: Pesquet’s parrot, vasa parrots
Psittaculidae: Australasian parrots
Passeriformes
– Worldwide; 5000 species
Acanthisittidae: New Zealand wrens
Eurylaimidae: broadbills
Philepittidae: asities
Pittidae: pittas
Sapayoidae: Sapayoa
Tyrannidae: tyrant flycatchers
Tityridae: becards and tityras
Furnariidae: ovenbirds
Thamnophilidae: antbirds
Formicariidae: ground antbirds
Rhinocryptidae tapaculos
Grallariidae: antpittas
Conopophagidae: gnateaters
Cotingidae: cotingas
Pipridae: manakins
Melanopareiidae: crescent-chests
Passeri: oscines
Atrichornithidae: scrub-birds
Menuridae: lyrebirds
Superb Lyrebird (Menura novaehollandiae)
Albert’s Lyrebird (Menura alberti)
Alaudidae: larks
Hirundinidae: swallows and martins
Motacillidae: wagtails and pipits
Campephagidae: cuckoo-shrikes
Eupetidae: Rail-Babbler
Pycnonotidae: bulbuls
Regulidae: kinglets
Hyliotidae: hyliotas
Chloropseidae: leafbirds
Aegithinidae: ioras
Ptilogonatidae: silky-flycatchers
Bombycillidae: waxwings
Hypocoliidae: Hypocolius
Dulidae: Palmchat
Cinclidae: dippers
Troglodytidae: wrens
Donacobiidae: Donacobius
Mimidae: mockingbirds and thrashers
Prunellidae: accentors
Turdidae: thrushes and relatives
Cisticolidae: cisticolas and relatives
Sylviidae:true warblers
Stenostiridae: fairy warblers
Macrosphenidae: African warblers
Cettiidae: bush warblers
Phylloscopidae: leaf warblers
Megaluridae: grass warblers
Acrocephalidae: marsh warblers
Bernieridae: malagasy warblers
Pnoepygidae: pygmy wren-babblers
Polioptilidae: gnatcatchers
Muscicapidae: flycatchers and relatives
Platysteiridae: wattle-eyes and batises
Petroicidae: Australasian robins
Pachycephalidae: whistlers and relatives
Colluricinclidae: shrike-thrushes and relatives
Picathartidae: rockfowl
Chaetopidae: rock-jumpers
Timaliidae: babblers and relatives
Panuridae: Bearded Reedling
Nicatoridae: nicators
Pomatostomidae: Australasian babblers
Orthonychidae: logrunners
Cinclosomatidae: whipbirds and quail-thrushes
Aegithalidae: bushtits
Maluridae: Australasian wrens
Neosittidae: sittellas
Climacteridae: Australasian treecreepers
Paridae: chickadees and true tits
Sittidae: nuthatches
Tichodromidae: Wallcreeper
Certhiidae: treecreepers
Rhabdornithidae: Philippine creepers
Remizidae: penduline tits
Nectariniidae: sunbirds
Melanocharitidae: berrypeckers
Paramythiidae: painted berrypeckers
Dicaeidae: flowerpeckers
Dasyornithidae: bristlebirds
Pardalotidae: pardalotes
Acanthizidae: Australasian warblers
Zosteropidae: white-eyes
Promeropidae: sugarbirds
Meliphagidae: honeyeaters and relatives
Notiomystidae: Stitchbird
Oriolidae: Old World orioles
Irenidae: fairy-bluebirds
Laniidae: shrikes
Malaconotidae: bushshrikes and relatives
Prionopidae: helmetshrikes and relatives
Vangidae: vangas
Dicruridae: drongos
Rhipiduridae: fantails
Monarchidae: monarch flycatchers
Callaeidae: wattlebirds
Corcoracidae: mudnesters
Artamidae: woodswallows and butcherbirds
Pityriaseidae: bristlehead
Paradisaeidae: birds-of-paradise
Cnemophilidae: satinbirds
Ptilonorhynchidae: bowerbirds
Corvidae: jays and crows
Sturnidae: starlings and mynas
Buphagidae: oxpeckers
Passeridae: Old World sparrows
Ploceidae: weavers and relatives
Estrildidae: weaver finches
Viduidae: whydahs and indigobirds
Vireonidae: vireos and relatives
Fringillidae: finches and relatives
Urocynchramidae: Pink-tailed Bunting
Peucedramidae: Olive Warbler
Parulidae: wood warblers
Coerebidae: Bananaquit
Thraupidae: tanagers and relatives
Emberizidae: Old World buntings and New World sparrows
Cardinalidae: cardinals, grosbeaks, and New World buntings
Icteridae: New World blackbirds and New World orioles