Birds Facts
Birds, members of the class Aves, include more than 10,400 living bird species – more than half being passerine, or “perching” birds. Their feathers distinguish them from all other classes of animal; no other animals on earth have them.
Beautiful to behold and charming to watch, there are many different types of birds that are often kept as pets by humans, and are the subject of many a story or photograph. Birdwatchers number in the millions while bird feeding is a multi-million dollar industry made possible by human beings’ love of our feathered friends.
If you see an animal with feathers, it’s undoubtedly a bird. Like mammals, birds are warm-blooded vertebrates with four-chambered hearts. However, birds are more closely related to reptiles and are believed to have evolved from dinosaurs. Their closest living relatives are the crocodilians.
Their forelimbs have been modified into wings over many millions of years of evolution, they lay hard-shelled eggs and they have exceptional vision – the most acute of their senses. Most types of bird species are diurnal, meaning they sleep at night.
Different types of birds may display different behaviors, though in general, birds are social creatures, communicating with songs, calls, chirps and movements. Some birds participate in cooperative hunting and travel in flocks. Many birds are monogamous – mostly for a breeding season but sometimes for life.
Most birds can fly, but flightless bird species exist.
Five Top Bird Characteristics
Certain identifying characteristics distinguish different types of birds from other classes of animals. Five especially important distinguishing characteristics of birds include:
Feathers
All birds species have feathers, which are actually highly evolved scales. In fact, birds have scales on their feet – the clearest reminder of their close relation to reptiles. As noted above, feathers are not found on any other class of animal. Like nails and hair on humans, feathers are made out of keratin. They serve a number of purposes, from providing warmth to assisting in the ability to fly. Most species of birds shed, or molt, their feathers one or two times per year. Contour feathers help birds to fly effectively and create a streamlined body shape. Soft, fluffy feathers provide warmth. Flight feathers, found on the wings and tail, provide loft. Male birds also often use their feathers to attract mates.
Wings
Wings are a primary characteristic of birds, but they are found on other types of animals too. For example, bats are flying mammals with wings, and many types of insects have wings. Strong muscles in the chest help to propel wings, allowing for flight. Bird bodies are curved specifically to give lift to the wings. Different wing shapes provide different advantages, depending on species. For example, wings that have sharp, narrow tips allow for greater speed. Wings that are longer than they are wide make it easier for birds to soar for extended periods of time. Elliptical, evenly shaped wings, which are most notably found on songbirds, allow for small, quick movement. Different types of birds are capable of swimming, like penguins and puffins, having wings that are shaped like flippers.
Beaks
All bird species have beaks, or bills – bony concentrations that are surrounded by layers of keratin. The shape of a bird’s beak provides strong clues about its dietary habits. Although some species of birds have tumia, sharp ridges along the edges of their beaks, none possess true teeth. Therefore, the beak plays a crucial role in feeding. Birds that primarily subsist off of seeds, for example, tend to have strong, cone-shaped beaks. Ducks, geese and other types of waterfowl have broad, flat beaks that are designed to help them strain food from water. Meat-eating birds like owls and hawks have sharp, hooked beaks that they use to grind, tear and rip their prey to shreds.
Eggs
Egg laying is another characteristic that is common to all birds, or members of the Aves class. However, it is not unique to this class of animals, as reptiles, fish, amphibians and insects also all lay eggs. Birds’ eggs have hard shells that are mostly made out of calcium; a layer of hardened mucus helps to keep them intact. Within an egg, the embryo gets its nutrition from the yolk and the egg white, which is known as albumin. The vast majority of bird species build nests for their eggs and proceed to care for the hatchlings until they are capable of fending for themselves. In most species, both males and females play important roles in caring for the young.
Nearly all species of birds incubate their eggs. Exceptions include megapodes, or mound builders, which rely on external heat sources like decaying vegetation, and brood parasites. The latter, including cuckoos and cowbirds, prefer to lay their eggs in other birds’ nests. Some birds, like murres and certain penguin species, don’t use nests at all, choosing instead to rest eggs on the tops of their feet during incubation. Incubation periods range from 11 to 80 days depending on species.
A set of eggs that is laid at one time is called a clutch. Anywhere from one to 20 eggs or so may be found in a single clutch. Some birds engage in determinate laying, meaning that they lay the same number of eggs per clutch every time. Most birds engage in indeterminate laying, meaning that the number per clutch varies.
There are many different types of birds eggs’ sizes and colorations. Linnet’s lay light blue eggs with dark streaking and spots.
©Olga Alyonkina/Shutterstock.com
Skeleton
Flightless species of birds have heavy bones that are filled with marrow. Birds that are capable of flight – in other words, most birds – have lightweight skeletons made up of hollow bones. Their skeletons have many fused bones, including collarbones, which help them to brace their wings effectively during flight. Birds have large breastbones, or sternums, that provide sturdy points of attachment for muscles of the wings.
Notable Types of Birds
Today, there are more than 10,400 extant different types of bird species in the world. Across North America and South America, there are more than 4,400 species of the Aves class. Approximately 2,700 different species are found in Asia, and another 2,300 or so are found in Africa. More than 500 species are found in Europe west of the Ural Mountains, and more than 700 species are found in Russia. Costa Rica has one of the highest concentrations of bird species – roughly 800.
Some of the most notable types of birds include:
- Birds of Prey – This group is made up of more than 300 species of birds, including eagles, hawks, ospreys, falcons and vultures.
- Cranes – This group, which includes coots and rails, boasts more than 200 species.
- Game Birds – Perhaps the best-known type of bird, game birds include chickens, turkeys, quails and megapodes. There are approximately 250 species of game birds in the world.
- Herons and Storks – More than 100 species are found in this group, which includes egrets, spoonbills and ibises.
- Hummingbirds and Swifts – The smallest category of birds, this group includes more than 400 different species.
- Ostriches – The ostrich, the most famous flightless bird, is also the only species in its genus. It also holds the distinction of being among the largest birds.
- Owls – Another important type of bird is the owl. There are more than 200 species of owls across the world.
- Parrots and Cockatoos – This colorful group, which includes macaws, cockatiels and budgerigars, consists of more than 350 species. They are popularly kept as pets.
- Penguins – There are roughly 20 species of this flightless bird in the world.
- Perching Birds – Also known as passerines, this group includes more than 5,000 species, making it the largest and most diverse. Common types of perching birds include crows, swallows, jays, finches, sparrows, wrens, starlings and larks.
- Pigeons and Doves – This group includes more than 300 bird species. Pigeons are famous for ferrying messages for humans, and have been used in such a way since Roman times. They were also used during World War I and II and the Korean War.
- Shorebirds – More than 350 species are found in this group, including sandpipers, terns, oystercatchers and gulls.
- Waterfowl – Ducks, geese, swans and many other birds belong to this group, which includes more than 150 species.
- Woodpeckers and Toucans – Known for their distinctive beaks, this group is made up of more than 400 species.
The theropod ancestor hypothesis states that birds evolved from theropod dinosaurs during the Jurassic period.
©Michael Rosskothen/Shutterstock.com
Evolution of Different Types of Birds
The evolution of birds has been a topic of much debate for many centuries. Today, the most commonly accepted theory, the theropod ancestor hypothesis, posits that birds evolved from theropod dinosaurs during the Jurassic period, which happened between 165 million and 150 million years ago.
Theropod dinosaurs were two-legged dinosaurs, and the T. Rex is included among their ranks.
The earliest known bird on the fossil record, archaeopteryx, was a hybrid between a bird and a dinosaur. It had feathered wings like a bird but also had sharp teeth and a long, bony tail like a dinosaur. This and other types of early birds diversified rapidly throughout the Jurassic and Cretaceous periods. They quickly became capable fliers and exhibited extremely rapid growth rapids.
However, their populations were decimated by the major extinction event that eliminated dinosaurs entirely. After that point, modern birds diversified at an explosive rate, and there are now more than 10,000 different species all across the world.
Types of Birds
List of Birds
- Adélie Penguin
- African Fish Eagle
- African Grey Parrot
- African Jacana
- African Penguin
- Albatross
- Amazon Parrot
- Amazonian Royal Flycatcher
- American Robin
- Anhinga
- Anna’s Hummingbird
- Australian Firehawk
- Avocet
- Ayam Cemani
- Bald Eagle
- Barn Owl
- Barn Swallow
- Barred Owl
- Baya
- Bearded Vulture
- Bee-Eater
- Belgian Canary
- Belted Kingfisher
- Bird
- Bird Of Paradise
- Black and White Warbler
- Black-Bellied Whistling Duck
- Black-Capped Chickadee
- Blackburnian Warbler
- Blackpoll Warbler
- Blue Gray Gnatcatcher
- Blue grosbeak
- Blue Jay
- Blue Tit
- Bobolink
- Booby
- Bronze-winged Jacana
- Brown Headed Cowbird
- Budgerigar
- Burrowing Owl
- Cactus Wren
- Canada Warbler
- Cardinal
- Carolina Parakeet
- Cassowary
- Cedar Waxwing
- Chestnut-Sided Warbler
- Chickadee
- Chicken
- Chinese Geese
- Chinstrap Penguin
- Chipping Sparrow
- Cinereous Vulture
- Clark’s Grebe
- Cockatiel
- Cockatoo
- Comb-crested Jacana
- Common Buzzard
- Common Grackle
- Common Green Magpie
- Common Loon
- Common Raven
- Common Yellowthroat
- Conure
- Cooper’s Hawk
- Cormorant
- Costa’s Hummingbird
- Crane
- Crested Penguin
- Crow
- Cuckoo
- Dark-Eyed Junco
- Dark-Eyed Junco
- Dodo
- Downy Woodpecker
- Dromornis stirtoni
- Duck
- Dunnock
- Eagle
- Eared Grebe
- Eastern Bluebird
- Eastern Kingbird
- Eastern Meadowlark
- Eastern Phoebe
- Eastern Turkey (Wild Turkey)
- Eclectus Parrot
- Egyptian Goose
- Egyptian Vulture
- Eider
- Elegant Tern
- Elephant Bird
- Elf Owl
- Emerald Toucanet
- Emperor Penguin
- Emu
- Eurasian Bullfinch
- Eurasian Collared Dove
- Eurasian Eagle-owl
- Eurasian Jay
- Eurasian Nuthatch
- Eurasian Sparrowhawk
- European Bee-Eater
- European Goldfinch
- European Robin
- European Starling
- Evening Grosbeak
- Fairy-Wren
- Falcon
- Ferruginous Hawk
- Finch
- Flamingo
- Frigatebird
- Galapagos Penguin
- Gentoo Penguin
- Goldcrest
- Golden Masked Owl
- Golden Oriole
- Golden-Crowned Kinglet
- Goose
- Goshawk
- Gouldian Finch
- Gray Catbird
- Great Blue Heron
- Great Crested Flycatcher
- Great Egret
- Great Kiskadee
- Great Potoo Bird
- Grebe
- Green Bee-Eater
- Green Heron
- Grey Heron
- Griffon Vulture
- Grouse
- Guinea Fowl
- Hairy Woodpecker
- Harpy Eagle
- Harris’s Hawk
- Hawaiian Crow
- Hawaiian Goose (Nene)
- Hawk
- Hepatic Tanager (Red Tanager)
- Heron
- Herring Gull
- Honey Buzzard
- Hooded Oriole
- Hoopoe
- Hornbill
- House Finch
- House Sparrow (English Sparrow)
- House wren
- Humboldt Penguin
- Hummingbird
- Hyacinth Macaw
- Ibis
- Ivory-billed woodpecker
- Jabiru
- Jacana
- Jackdaw
- Junglefowl
- Kagu
- Kakapo
- Kaua’i ‘Ō‘ō
- Keel-Billed Toucan
- Kentucky Warbler
- Kestrel
- Killdeer
- King Penguin
- King Quail
- King Vulture
- Kingfisher
- Kiwi
- Kori Bustard
- Lappet-faced Vulture
- Laughing Kookaburra
- Least Flycatcher
- Lesser Jacana
- Lesser Scaup
- Linnet
- Little Penguin
- Long-Eared Owl
- Long-Tailed Tit
- Lorikeet
- Lyrebird
- Macaroni Penguin
- Macaw
- MacGillivray’s Warbler
- Madagascar Jacana
- Magellanic Penguin
- Magnolia Warbler
- Magpie
- Mallard
- Marabou Stork
- Mexican Eagle (Northern crested caracara)
- Mississippi Kite
- Mockingbird
- Mountain Bluebird
- Mourning Dove
- Mourning Warbler
- Muscovy Duck
- Myna Bird
- Nicobar pigeon
- Night Heron
- Nightingale
- Nightjar
- Northern Bobwhite
- Northern Cardinal
- Northern Flicker
- Northern Jacana
- Northern Pintail
- Northern Potoo
- Northern Screamer
- Nuthatch
- Orange-Crowned Warbler
- Orchard Oriole
- Oriental Dwarf Kingfisher
- Ortolan Bunting
- Osprey
- Ostrich
- Ovenbird
- Owl
- Oxpecker
- Painted Bunting
- Parakeet
- Parrot
- Parrotlet
- Partridge
- Peacock
- Pelican
- Penguin
- Peregrine Falcon
- Pesquet’s Parrot (Dracula Parrot)
- Pheasant-tailed Jacana
- Phoenix Chicken
- Pied-Billed Grebe
- Pigeon
- Pileated Woodpecker
- Pine Siskin
- Pink-Necked Green Pigeon
- Potoo
- Prairie Chicken
- Puffin
- Purple Finch
- Purple Gallinule
- Quail
- Quetzal
- Red Finch
- Red Kite
- Red-Bellied Woodpecker
- Red-Billed Quelea Bird
- Red-Shouldered Hawk
- Red-winged blackbird
- Redstart
- Rhea
- Ring-billed Gull
- Ringed Kingfisher
- Robin
- Rockhopper Penguin
- Rooster
- Rose-Breasted Grosbeak
- Roseate Spoonbill
- Royal Penguin
- Ruby-Crowned Kinglet
- Ruby-Throated Hummingbird
- Ruddy Duck
- Ruddy Turnstone
- Rufous Hummingbird
- Sandhill Crane
- Sandpiper
- Sarus Crane
- Savannah Sparrow
- Scale-Crested Pygmy Tyrant
- Scarlet Macaw
- Scissor-tailed Flycatcher
- Sea Eagle
- Seagull
- Sedge Warbler
- Senegal Parrot
- Sharp-Shinned Hawk
- Shoebill Stork
- Short-Eared Owl
- Silkie Chicken
- Skua
- Snow Bunting
- Snow Goose
- Snowy Owl
- Song Sparrow
- Song Thrush
- Sparrow
- Sparrowhawk
- Spixs Macaw
- Stork
- Summer Tanager
- Swainson’s Hawk
- Swallow
- Swan
- Tawny Frogmouth
- Tawny Owl
- Thrush
- Toucan
- Towhee
- Tree swallow
- Treecreeper
- Tropicbird
- Tufted Coquette
- Tufted Titmouse
- Tundra Swan
- Turaco
- Turkey
- Turkey Vulture
- Uguisu
- Umbrellabird
- Ural owl
- Veery
- Vermilion Flycatcher
- Vulture
- Wandering Albatross
- Warbler
- Wattled Jacana
- Weaver Bird
- Western Kingbird
- Western Tanager
- Whimbrel
- Whinchat
- White-Crowned Sparrow
- White-Tailed Eagle
- Whooping Crane
- Willow Flycatcher
- Willow Warbler
- Wood Duck
- Woodpecker
- Wryneck
- Xeme (Sabine’s Gull)
- Yellow Bellied Sapsucker
- Yellow-Eyed Penguin
- Yellowhammer
- Yokohama Chicken
- Zebra Finch
More Great Birds Content
- How Many Birds Are In The World?
- Bird Mating Season: When Do They Breed?
- The Top 9 Largest Flying Birds in the World By Wingspan
- Top 9 Largest Eagles in the World
- What Do Ducklings Eat? 13 Foods for Baby Ducks
- The Top 10 Fastest Birds in the World
- What Do Crows Eat? 15-Plus Foods They Love!
- 7 Deadliest Birds On Earth
- Think you know Birds? Take our brand new Birds Quiz.
FAQs (Frequently Asked Questions)
What are the four types of birds?
There are far more than only four types, or categories, of birds in the world. If “type” refers to “species,” then the figure is closer to around 10,400. Birds can be classified into different categories in a number of ways, including flightless birds versus birds that are capable of flight and birds that live mostly on land or near water.
How are birds identified?
Birdwatching, a popular pastime, involves identifying birds in the wild. Four things are looked to when identifying birds: their size and shape, their behavior, their habitat and their color patterns. By learning the basics of each of these categories, birdwatchers can identify birds in the wild more quickly – an important aspect of the sport.
Why do birds bathe?
Bathing is a vital part of feather maintenance. Water helps to loosen up dirt and other debris that has worked its way into the feathers. Once freed of dirt, the feathers are easier to preen. During preening, birds rearrange their feathers and dispense oil from the preen gland, ensuring that their feathers remain waterproof. This also traps an insulating layer of air beneath, helping to keep the bird warm.
Which birds cannot fly?
Some of the best-known examples of flightless birds include penguins, ostriches, emus, cassowaries and kiwis.
Thank you for reading! Have some feedback for us? Contact the AZ Animals editorial team.