Glossary of bird terms

The following is a glossary of common English language terms used in the description of birds—warm-blooded vertebrates of the class Aves and the only living dinosaurs.

[1] Birds, who have feathers and the ability to fly (except for the approximately 60 extant species of flightless birds), are toothless, have beaked jaws, lay hard-shelled eggs, and have a high metabolic rate, a four-chambered heart, and a strong yet lightweight skeleton.

Among other details such as size, proportions and shape, terms defining bird features developed and are used to describe features unique to the class—especially evolutionary adaptations that developed to aid flight.

There are, for example, numerous terms describing the complex structural makeup of feathers (e.g., barbules, rachides and vanes); types of feathers (e.g., filoplume, pennaceous and plumulaceous feathers); and their growth and loss (e.g., colour morph, nuptial plumage and pterylosis).

Though words that are not unique to birds are also covered, such as "back" or "belly," they are defined in relation to other unique features of external bird anatomy, sometimes called "topography."

External anatomy ( topography ) of a typical bird: 1 beak , 2 head , 3 iris , 4 pupil , 5 mantle , 6 lesser coverts , 7 scapulars , 8 coverts , 9 tertials , 10 rump , 11 primaries , 12 vent , 13 thigh , 14 tibio-tarsal articulation , 15 tarsus , 16 feet , 17 tibia , 18 belly , 19 flanks , 20 breast , 21 throat , 22 chin , 23 eyestripe
Drawing of the various parts of a bird's wing
Location of the alula on a bird's wing
A yellow-legged gull ( Larus michahellis ) in flight. Apical spots tinge the row of feathers on the trailing edges of its wings.
Explanatory diagram showing the interlocking of the barbs of feathers
Comparison of bird bills , displaying different shapes adapted to different feeding methods (not to scale)
A female Javan banded pitta ( Hydrornis guajanus ), with a numbered ring banding its left leg
Black herons canopy feeding .
A pair of knobbed hornbills with prominent casques on display
A rooster with a large red comb
A white cockatoo , also called the umbrella cockatoo from the shape of its crest
A grey catbird , with its distinctly coloured crissum on display
A greater flamingo chick being fed crop milk
refer to caption
A female common eider sits on her nest, surrounded by down feathers
Eggs of: ostrich, emu, kiwi and chicken
A Senegal parrot chick at about two weeks after hatching. The egg tooth is near the tip of its beak on the upper mandible .
Feather variations
The military macaw on the left is displaying signs of feather-plucking .
Illustration of a goose filoplume feather, from The Structure and Life of Birds (1895).
Parts of a feather:
The gape flange on this juvenile house sparrow is the yellowish region at the base of the beak.
Male Costa's hummingbird ( Calypte costae ) with an iridescent gorget
Bird with a wing outstretched, rearranging feathers with the tip of its bill
Barn Swallow preening ; one of many maintenance behaviours
New Zealand pipit Anthus novaeseelandiae novaeseelandiae , displaying a prominent moustachial stripe
Close up of a lesser whistling duck . Note the hooked nail at the tip of the beak.
An overview of the diversity in nest placement and construction
The nictitating membrane as it covers the eye of a masked lapwing
Topography of a typical passerine
A budgerigar with pin feathers showing on its breast.
The differences in plumage of blue grosbeak , from top to bottom, between a breeding male ( alternate plumage ), a non-breeding male ( basic plumage ), a female and a related indigo bunting
A house sparrow cleans itself in moving water while a mallard preens in the background.
Pterylosis (feather arrangement) of a typical passerine
Breeding summer visitor
Resident year-round
Winter visitor

Range map for Eurasian blackcaps —corresponding to the example use of " resident " in its definition at the left
Rictal bristles of a white-cheeked barbet
Scales on the talons of a Steller's sea eagle ( Haliaeetus pelagicus )
Sexually dimorphic female (left) and male (right) common pheasant , illustrating the dramatic difference in both colour and size between the species' sexes
A male mallard . Note the white-edged, blue and black speculum seen on the wing.
A barn swallow displaying tail streamers
Pigeon skeleton. Number 8 indicates both left and right tarsometatarsus
The sawtooth serrations of a common merganser 's tomia help it to hold tight to its fish prey.
Underwing of bird showing feather nomenclature: 1 axillaries , 2 margin (marginal underwing coverts), 3 lesser underwing coverts , 4 median underwing coverts (secondary coverts), 5 greater underwing coverts (secondary coverts), 6 carpal joint, 7 lesser underwing primary coverts, 8 greater underwing primary coverts, 9 secondaries , 10 primaries
An adult male bearded bellbird calling in the Arima Valley of Trinidad. Note the beard-like wattles sprouting from its chin and throat area, for which the bird is named.
A female pine siskin with white wing bars .
Topside of a chicken wing showing all major feather groups
Male bee hummingbird in flight; the bird with the smallest wingspan at 6.6 cm (2.6 in).