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ORNITHOLOGICAL GLOSSARY

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z


A

adaptive radiation

Diversification of a single type of organism into multiple types each adapted to a specialized environmental niche.

adaptive radiation
adaptive radiation      Carduelis tristis

air sacs

A set of thin-walled chamber that allow air to flow in a continuous direction in the lungs. The air sacs are depicted in blue.

air sacs
air sacs      0

airfoil

A wing or other structure designed (or evolved) to provide lift and control in flight.

airfoil
airfoil      0

albino

An animal lacking in pigments resulting in white feathers and reddish soft parts.

albino
American Robin      Turdus migratorius

allopreening

Mutual preening between two birds.

allopreening
Burrowing Owl      Athene cunicularia

alternate plumage

Breeding plumage or nuptial plumage.

alternate plumage
Magnolia Warbler      Setophaga magnolia

altricial

Born helpless, often naked with eyes closed.

altricial
Palm Warbler      Setophaga palmarum

alula

Three to five feathers in wrist of the wing that are used in slow flight or landing, much as slots on an airplane.

alula
Rock Pigeon      Columba livia

anisodactlyl feet

Most common pattern of bird toes, with the hallux pointing to the rear and three toes pointing forward.

anisodactlyl feet
Peregrine Falcon      Falco peregrinus

aposematic

A warning signal that advertises the unpalatablity of a bird or other animal.

aposematic
Black-headed Pitohui      Pitohui dichrous

auricular

Area around the ear opening on the side of a bird’s head. Note blue auricular feathers above.

auricular
Green Violetear      Colibri thalassinus

axillary

Area between the body and ventral surface of the wing. Note black axillary feathers in Black-bellied Plover

axillary
Black-bellied Plover      Pluvialis squatarola

B

     

basic plumage

Non-breeding or winter plumage - typically duller colored

basic plumage
Magnolia Warbler      Setophaga magnolia

belly

The ventral part of the bird below the breast and above the legs. Above, it is the red area above the legs.

belly
Red-bellied Grackle      Hypopyrrhus pyrohypogaster

bill

The beak

bill
Golden-collared Toucanet      Selenidera reinwardtii

bill-wiping

The behavior of birds wiping the bill clean of sticky food or other substances after feeding

bill-wiping
American Robin      Turdus migratorius

binocular vision

Three-dimensional vision resulting from overlapping fields of vision due to placement of the eyes facing forward

binocular vision
Luzon Scops-Owl      Otus longicornis

booming sacs

Inflatable offshoots of the esophagus covered with bright-colored skin used in courtship display

booming sacs
Greater Sage-Grouse      Centrocercus urophasianus

bounding flight

Undulating flight pattern with short bursts of flapping followed by wings folded against the body

bounding flight
bounding flight      0

bower

A structure built by males of certain promiscuous species to attract females

bower
Gardener Bowerbird      Amblyornis inornatus

breast

The chest - the area between the throat andbelly. The blue in the front of this kingfisher corresponds to the area of the breast.

breast
Blue-breasted Kingfisher      Halcyon malimbica

bristles

Stiff feathers without vanes or barbules

bristles
Bearded Barbet      Lybius dubius

bronchi

The air passageway that transports air from the trachea to the lungs

bronchi
bronchi      0

brood

The young birds derived from one clutch of eggs

brood
Mute Swan      Cygnus olor

brood parasite

A bird that lays its egg in the nest of another bird. Cowbirds and Old World cuckoos are the most familiar examples.

brood parasite
Bronzed Cowbird      Molothrus aeneus

brood patch

A highly vascularized, featherless area on the belly of incubating birds

brood patch
Large-billed Blue-Flycatcher      Cyornis caerulata

C

     

camouflage

Use of features that blend in with the environment to hide

camouflage
Little Bittern      Ixobrychus minutus

carotenoid

Organic pigments derived from plants and used by birds to color feathers and soft parts

carotenoid
Holub's Golden Weaver      Ploceus xanthops

casques

Hollow, bony extension of the skull in hornbills, such as in some hornbills and cassowaries.

casques
Great Hornbill      Buceros bicornis

cavity nest

A nest in a hole in a tree, bank, or the ground

cavity nest
Hyacinth Macaw      Anodorhynchus hyacinthinus

central fovea

An area of densely packed cells near the center of the retina that perceives sharper images

central fovea
central fovea     

cere

Leathery skin around the nostrils in birds such as hawks and pigeons

cere
Plumbeous Forest-Falcon      Micrastur plumbeus

chin

A small area directly behind the mandible

chin
White-chinned Petrel      Procellaria aequinoctialis

choacal protuberance

Enlargement of the cloacal region in some birds during breeding season, caused by the swelling of tubules that store sperm

choacal protuberance
cloacal protuberance     

choana

An opening in the roof of the mouth that leads to the two nasal cavities

choana
choana     

clay lick

An area of clay visited by birds, which eat the clay for its mineral content

clay lick
Dusky-headed Parakeet      Aratinga weddellii

cline

A gradual change in characters of members of the same species along a gradient of environmental or geographical transition

cline
cline     

cloaca

Common opening for excretory, urinary, and reproductive systems

cloaca
Gentoo Penguin      Pygoscelis papua

cloacal bursa

An organ off of the cloaca, active in young birds, that produces B cells, specialized white blood cells

cloacal bursa
cloacal bursa     

clutch

The set of eggs laid by a single female during one bout of nesting. Here is a clutch size of four.

clutch
American Robin      Turdus migratorius

coevolution

Reciprocal adaptations evolved by two or more organisms in response to changes in the other species

coevolution
coevolution     

colony

A group of birds nesting together

colony
Black-browed Albatross      Thalassarche melanophris

comb

A fleshy growth on the top of the head, especially in chickens

comb
Red Junglefowl      Gallus gallus

commensal

A relationship between to animals that helps one species while being neither a help or hindrance to the other

commensal
Cattle Egret      Bubulcus ibis

communal roost

A site used by large numbers of birds to sleep

communal roost
Cattle Egret      Bubulcus ibis

cones

Color sensitive cells in the retina

cones
cone     

contour feathers

The typical feathers covering a bird with a long central shaft and a broad vane

contour feathers
Wild Turkey      Meleagris gallopavo

convergent evolution

A situation where two unrelated species evolve similar features because of similar environments. Example: Yellow-throated Longclaw from Africa and Eastern Meadowlark from the Americas.

convergent evolution
Yellow-throated Longclaw      Macronyx croceus

cooperative foraging

A feeding strategy in which individuals in a group benefit by working together to catch prey

cooperative foraging
American White Pelican      Pelecanus erythrorhynchos

coracoid

Bone connecting the sternum to the shoulder

coracoid
coracoid     

courtship display

Ritualized posturing and movements used mostly by males, or both sexes together, to attract mates

courtship display
Western Grebe      Aechmophorus occidentalis

courtship feeding

Transfer of food from the male to the female during courtship and early stages of nesting

courtship feeding
Gull-billed Tern      Gelochelidon nilotica

coverts

Feathers that overlap wing or tail feathers, covering the base of those feathers

coverts
Yellow-billed Stork      Mycteria ibis

crèche

A group of bird chicks from different broods attended by a smaller number of adults, freeing other parents to forage

crèche
Emperor Penguin      Aptenodytes forsteri

crepuscular

Active at dusk or dawn

crepuscular
European Nightjar      Caprimulgus europaeus

crop

A sac off of the esophagus used to store food

crop
Harris's Hawk      Parabuteo unicinctus

crop milk

Liquid protein from cells grown in a pigeon's crop. Also known as pigeon milk.

crop milk
Mourning Dove      Zenaida macroura

crown

The top of a birds head

crown
Blue-crowned Manakin      Lepidothrix coronata

cup nest

An open nest with a shape like a teacup minus the handle

cup nest
Hooded Warbler      Setophaga citrina

D

     

decurved

Curved in a downward fashion

decurved
Long-billed Curlew      Numenius americanus

disjunct range

An area of distribution for an organism that is separate from the main area of distribution

disjunct range
disjunct range     

distraction display

Actions taken by a parent bird, such as feigning a broken wing, or acting uncoordinated to distract a predator from the nest or chicks

distraction display
Killdeer      Charadrius vociferus

#N/A

down feathers

Fluffy, soft feathers of young birds or similar feathers beneath the contour feathers of some adult birds

down feathers
Red-footed Booby      Sula sula

drag

The force that resists movement through the air

drag
drag force     

drumming

The beating of the wings by a grouse during courtship causing the air to make a thumping sound. Also the rapid hammering of a woodpecker to create a sound proclaiming its territory

drumming
Ruffed Grouse      Bonasa umbellus

dust-bathing

Crouching and fluttering in dust or dry dirt to spread fine particles into feathers to get rid of ectoparasites and maintain feathers

dust-bathing
Northern Bobwhite      Colinus virginianus

dynamic soaring

A mode of flight in which the bird gains energy by repeatedly crossing between air masses with different velocities. Albatrosses, for example, gain lift by repeatedly crossing from the calm of a wave trough to headwinds above the waves.

dynamic soaring
dynamic soaring     

E

     

eclipse plumage

A female-like plumage acquired by male ducks and some other birds after breeding

eclipse plumage
Mallard      Anas platyrhynchos

ectoparasite

A parasite that lives on the outside of an animal, such as a tick, mite, or leech

ectoparasite
Red-legged Thrush      Turdus plumbeus

egg

The reproductive product of a bird

egg
Brown-headed Cowbird      Molothrus ater

egg tooth

A small sharp knob near the tip of the beak that helps the chick break open the egg. It falls of or is resorbed within a few days of hatching.

egg tooth
Laughing Gull      Leucophaeus atricilla

embryo

The developing chick within an egg

embryo
Atlantic Petrel      Pterodroma incerta

epaulettes

Bright-colored patches of feathers at the base of a bird's wings

epaulettes
Long-tailed Widowbird      Euplectes progne

esophagus

The passageway from the mouth to the stomach

esophagus
esophagus     

external ear

The open of the ear leading to the tympanum or ear drum. In most birds it is shallow and covered with specialized feathers.

external ear
Double-wattled Cassowary      Casuafalcorius casuarius

eye comb

A bright-colored skin over the eye in some birds such as grouse

eye comb
Spruce Grouse      Falcipennis canadensis

eye ring

A circle of bare skin immediately around the eye

eye ring
Dagua Thrush      Turdus daguae

eyeline

A line created by colored feathers that continues on both sides of the eye

eyeline
Chipping Sparrow      Spizella passerina

F

     

feather tracts

Regions of skin where feathers attach, also known as pterylae. Here seen as dark bands on lighter skin.

feather tracts
Painted Bunting      Passerina ciris

fecal sac

A membrane covered packet containing the feces and uric acid that is collected from the chick's cloaca by the parent bird

fecal sac
Red-eyed Vireo      Vireo olivaceus

femur

The proximal (upper) leg bone

femur
femur     

fibula

The smaller of two bones on the shin or calf, familiar to many as the skinny bone in the drumstick

fibula
fibula     

filoplumes

Fine, vaneless, hairlike feathers that have sensory receptors adjacent to their follicles

filoplumes
Yellow-bellied Bulbul      Criniger phaeocephalus

flank

The upper sides of a bird

flank
Hooded Merganser      Lophodytes cucullatus

fledgling

A chick that has recently flown from the nest for the first time

fledgling
White-crowned Pigeon      Patagioenas leucocephala

flight feathers

The remiges and retrices--major tail and wing feathers

flight feathers
Egyptian Vulture      Neophron percnopterus

flight song

A courtship or territorial song sung in flight

flight song
European Sedge-Warbler      Acrocephalus schoenobaenus

forehead

The part of the crown just above the beak

forehead
Plushcap      Catamblyrhynchus diadema

forked tail

A tail with a notch in the center

forked tail
Fork-tailed Drongo      Dicrurus adsimilis

frugivorous

Eating fruit as the major part of the diet

frugivorous
Fawn-breasted Tanager      Pipraeidea melanonota

furcula

The fused clavicles of a bird - popularly known as the wishbone

furcula
furcula     

G

     

gape flange

The soft tissue where the two halves of the jaw join--often conspicuous in nestlings and juvenile birds

gape flange
Ocellated Antbird      Phaenostictus mcleannani

gizzard

The muscular section of the avian stomach which grinds food

gizzard
gizzard     

gleaning

Picking prey off of leaves and other surfaces

gleaning
Swainson's Thrush      Catharus ustulatus

glenoid fossa

The rounded depression in the scapula that articulates with the head of the humerus and allows the wing to rotate

glenoid fossa
glenoid fossa     

gliding

Flying without flapping while losing altitude slowly

gliding
gliding     

globular nest

A spherical nest, typically with the opening on the side

globular nest
Grosbeak Weaver      Amblyospiza albifrons

graduated tail

A tail in which the retrices are progressively longer toward the center

graduated tail
Rose-ringed Parakeet      Psittacula krameri

grazing

Feeding on grass and other herbaceous plants

grazing
Barnacle Goose      Branta leucopsis

greater coverts

The row feathers that lies immediately above the flight feathers (On the shoveler, the white row of feathers above the secondaries and the corresponding row over the primaries)

greater coverts
Northern Shoveler      Anas clypeata

guano

The accumulated droppings of colonial birds, especially seabirds. It is mined as fertilizer in some places. Guano covers much of this hill.

guano
Peruvian Booby      Sula variegata

guild

A group of birds in one area that exploits resources in a similar fashion. Illus. army ant followers in Panama: A Northern Barred Woodcreeper, B Plain Brown Woodcreeper, C Rufous-vented Ground-Cuckoo, D Ocellated Antbird, E Gray-headed Tanager, F Spotted Antbird, G Bicolored Antbird

guild
guild     

gular Sac

Expandable pouch of skin just below the chin which can be used for panting to cool the bird

gular Sac
Double-crested Cormorant      Phalacrocorax auritus

H

     

hallux

The first toe, usually pointing backwards

hallux
Wild Turkey      Meleagris gallopavo

hatch

To emerge from the egg

hatch
Gentoo Penguin      Pygoscelis papua

hatchling

A bird that has just emerged from the egg

hatchling
Lesser Frigatebird      Fregata ariel

hawking

Feeding by flying out from a perch to snatch prey and returning to that perch

hawking
hawking     

herbivore

An animal that eats plant material exclusively or almost so

herbivore
Hoatzin      Opisthocomus hoazin

heterodactyl foot

A bird foot in which digits three and four face forward, while the first and second digit face backward. Trogons have this pattern.

heterodactyl foot
Masked Trogon      Trogon personatus

hooklets

Tiny hooks on the barbules of feathers that keep the barbs and barbules from separating

hooklets
Hooklets     

hover

Flying in a stationary position

hover
Osprey      Pandion haliaetus

humerus

The wing bone closest to the body

humerus
humerus     

hybrid

A cross between two different species

hybrid
Hybrid Duck Mallard x Pintail      A. platyrhynchos x A. acuta

I

     

ilium

The largest and uppermost bone in the pelvic girdle. It is fused with the ischium and synsacrum.girdle.

ilium
ileum     

imprinting

Behaviors that are learned and fixed during a limited critical period in a bird's early life

imprinting
Upland Goose      Chloephaga picta

incubation

Maintaining the eggs at a constant temperature ideal for development. Most birds incubate by sitting on the eggs but megapodes incubate in compost or warm sand.

incubation
Least Tern      Sternula antillarum

infundibulum

The funnel shaped anterior end of the oviduct that accepts the egg during ovulation

infundibulum
infundibulum     

iridescence

Glittering colors that change with the angle of view, caused by structural features of feathers that scatter light. A famiiar example is the feathers on a Rock Pigeon's neck.

iridescence
Nicobar Pigeon      Caloenas nicobarica

iris

The colored circular diaphragm in the eye that controls the amount of light hitting the retina

iris
Semiplumbeous Hawk      Leucopternis semiplumbeus

ischium

The large pelvic bone posterior to the leg joint and fused with the posterior portion of the synsacrum

ischium
ischium     

J

     

juvenile

A young bird, usually in the first months after fledging, that has its first set of contour feathers

juvenile
Herring Gull      Larus argentatus

K

     

keel

A large, flat ridge of bone that extends perpendicularly from the main portion of the sternum The major flight muscles, the pectoralis and the suprcoracoideus, attach to the keel. Also known as carina.

keel
keel     

keratin

A fibrous protein that is the chief component of feathers, scales and claws

keratin
Common Poorwill      Phalaenoptilus nuttallii

kettle

A group of rising birds soaring in a spiral motion in a thermal

kettle
Turkey Vulture      Cathartes aura

kleptoparasite

An animal that habitually steals food from another animal

kleptoparasite
Magnificent Frigatebird      Fregata magnificens

L

     

lacrimal gland

The structure at the ventral side of the eye that secretes tears

lacrimal gland
lacrimal glands     

laminar flow

Smooth flow of air over the surface of the wing

laminar flow
laminar flow     

lek

A communal display ground for promiscuous male birds

lek
Greater Sage-Grouse      Centrocercus urophasianus

lens

The hard, transparent area inside the eye that focuses light

lens
lens     

lesser coverts

The rows of feathers on the wing immediately over the greater coverts

lesser coverts
African Pygmy Kingfisher      Ispidina picta

lore

The area between the eye and the beak--chartreuse on this breeding Great Egret

lore
Great Egret      Ardea alba

M

     

malar region

The lower part of the face extending behind the lower beak, seen here in black on this Northern Flicker

malar region
Northern Flicker      Colaptes auratus

mandible

The lower half of the beak

mandible
Black Skimmer      Rynchops niger

melanism

Darkening of pigmented feathers due to extra melanin (a class of pigments) , in this case making a normally white Cattle Egret, blackish

melanism
Cattle Egret      Bubulcus ibis

mesobronchus

The extension of the bronchus inside the lungs leading to the abdominal air sacs

mesobronchus
mesobronchi     

metacarpals

The three bones that fuse to form the carpometacarpus distal to the humerus

metacarpals
metacarpal     

migration

Seasonal movement of birds from one area to another

migration
American White Pelican      Pelecanus erythrorhynchos

mimicry

In birds, most often used for vocal mimicry, in which one species imitates the vocalizations of another. Mockingbirds are "open-ended" learners and can add new songs to their repetoire thoughout their life.

mimicry
Northern Mockingbird      Mimus polyglottos

molt

Periodic loss and regrowth of feathers. This Ring-billed Gull shows wing molt.

molt
Ring-billed Gull      Larus delawarensis

monocular vision

Sight in which each eye is used separately with little overlap in the field of view of each eye

monocular vision
American Woodcock      Scolopax minor

monogamy

Maintaining a single mate, at least for the duration of nesting

monogamy
Scarlet Macaw      Ara macao

morph

Groups of birds that differ in body size, bill shape, color or other features from other groups of birds of the same species. The two color morphs of Reddish egrets shown here.

morph
Reddish Egret      Egretta rufescens

mound nest

A nest made from a heap of sand, sticks or other material with an egg chamber inside, particularly those of the moundbuilders

mound nest
Mallee Fowl      Leipoa ocellata

mycoplasmal conjunctivitis

A disease, most commonly observed in House Finches, in which the eye is swollen, crusty and sometimes shut

mycoplasmal conjunctivitis
House Finch      Haemorhous mexicanus

N

     

nape

The region at the back of the neck

nape
Yellow-naped Parrot      Amazona auropalliata

nares

The external openings of the nose

nares
Turkey Vulture      Cathartes aura

natal down

Loose, fluffy feathers of young birds prior to developing contour feathers

natal down
Whiskered Tern      Chlidonias hybrida

nest

The structure in which a bird lays and incubates its eggs

nest
Black-browed Albatross      Thalassarche melanophris

nest appropriation

Using the nest of another bird, typically after the other bird has ceased to use it. This horned owl has appropriated a hawk nest.

nest appropriation
Great Horned Owl      Bubo virginianus

nictitating membrane

A transparent membrane that slides sideways over the eye, moistening or protecting it

nictitating membrane
Red-headed Vulture      Sarcogyps calvus

nidifugous

Leaving the nest shortly after hatching

nidifugous
Dunlin      Calidris alpina

nocturnal

Active at night

nocturnal
Eastern Screech-Owl      Megascops asio

O

     

oil gland

A sebaceous gland near the dorsal base of the tail that produces oil for preening, also known as uropygial gland or preen gland

oil gland
Black-crowned Night-Heron      Nycticorax nycticorax

omnivore

An animal that eats both plant and animal material

omnivore
Gila Woodpecker      Melanerpes uropygialis

operculum

A structure that covers the nares in some birds

operculum
Rock Pigeon      Columba livia

oral flanges

See gape flanges

oral flanges
Canyon Wren      Catherpes mexicanus

oviduct

The long, convoluted tube through which the egg passes from ovary to cloaca. Albumin, membranes and egg shell are added in the oviduct.

oviduct
oviduct     

P

     

pamprodactyl feet

Feet with toes all arranged in a forward orientation, as in some swifts

pamprodactyl feet
Chimney Swift      Chaetura pelagica

pecten

A comb-shaped structure of blood vessels inside the avian eye extending out from the optic nerve. It is thought to nourish the retina and control the ph of the vitreous humor.

pecten
pecten     

pectinate claw

A claw with a comb-like edge found in heron family and in nightjars and Barn Owls. It is presumably used for preening.

pectinate claw
Tricolored Heron      Egretta tricolor

pectoral girdle

The bones connecting the wing with the main part of the skeleton. It consists of the furcula, scapulas , coracoids , and sternum.

pectoral girdle
pectoral girdle     

pectoralis

The large breast muscle that powers the downstroke of flight by depressing the wing at the shoulder

pectoralis
pectoralis major     

pelagic species

A bird that spends its life on the open ocean. Pelagic birds typically only coming to land to breed.

pelagic species
Pink-footed Shearwater      Puffinus creatopus

pellet

The regurgitated bolus of indigestible prey parts expelled by owls, kingfishers and other birds

pellet
Snowy Owl      Bubo scandiacus

pelvic girdle

The fused ilium, ischium, , pubis, and fused sacral vertebrae. Together they form an anchor for the tail and leg muscles.

pelvic girdle
pelvic girdle     

pendulous cup nest

A sock-shaped nest suspended from twigs, especially by orioles, oropendolas, and caciques.

pendulous cup nest
Crested Oropendola      Psarocolius decumanus

pensile cup nest

A cuplike nest suspending by the rim typical of vireos, some blackbirds, and kinglets.

pensile cup nest
Warbling Vireo      Vireo gilvus

phalanges

The finger bones--reduced in birds.

phalanges
phalanges     

pigments

Chemical compounds that absorb light of specific wavelengths giving feathers and soft parts their colors.

pigments
Scarlet Macaw      Ara macao

pin feathers

Growing feathers still covered by the feather sheath

pin feathers
Little Blue Heron      Egretta caerulea

pipped

Describing an egg that has a small hole made by a chick about to hatch

pipped
American White Pelican      Pelecanus erythrorhynchos

piracy

Stealing food from other birds, typically from other species

piracy
Brown Noddy      Anous stolidus

platform nest

Nests built of sticks piled on each other with a low depression for the eggs

platform nest
Osprey      Pandion haliaetus

plumage

The set of feathers that cover a bird, or a seasonal or age-related pattern of the feathers

plumage
Scarlet Tanager      Piranga olivacea

plunge diving

Diving from the air into water after prey using momentum to overcome buoyancy. Typical of pelicans, boobies, gannets, and most terns.

plunge diving
Blue-footed Booby      Sula nebouxii

pneumatic bones

Hollow bones containing extensions of air sacs. Their light weight makes them an important adaptation for flight.

pneumatic bones
pneumatic bones     

polyandry

A form of polygamy in which a female has more than one male mate at a time

polyandry
Spotted Sandpiper      Actitis macularia

polygamy

A breeding system in which a member of one sex takes multiple mates of the opposite sex

polygamy
Marsh Wren      Cistothorus palustris

polygyny

Mating system in which each male may mate with multiple females

polygyny
Red-winged Blackbird      Agelaius phoeniceus

polymorphism

Two or more different forms (at the same life stage) in the same species, such as two distinct color variations or morphs

polymorphism
Ruff      Philomachus pugnax

porphyrins

A group of pigments responsible for certain brown and green feather coloration and in one case magenta

porphyrins
Schalow's Turaco      Tauraco schalowi

precocial

Baby birds hatched with down and with eyes open, ready to leave the nest

precocial
Canada Goose      Branta canadensis

precopulatory display

Ritualized postures and vocalizations uniquely performed prior to copulation

precopulatory display
Yellow-headed Blackbird      Xanthocephalus xanthocephalus

preening

Cleaning and arranging the feathers typically with the beak

preening
White Ibis      Eudocimus albus

premaxilla

The main bone of the upper half of the beak

premaxilla
premaxilla     

primaries

Flight feathers attached to the outermost segment of the wing. In the Palm Nut Vulture they have white bases.

primaries
Palm-nut Vulture      Gypohierax angolensis

promiscuous

Describing a species in which one sex breeds with multiple mates

promiscuous
Greater Sage-Grouse      Centrocercus urophasianus

proventriculus

The glandular chamber of the avian stomach between the esophagus and the gizzard

proventriculus
proventriculus     

pupil

The opening in the center of the eye, through which light passes

pupil
Scale-feathered Cuckoo      Lepidogrammus cumingi

pygostyle

The last bone at the posterior end of the vertebral column, which supports the tail feathers and related musculature. It is formed by several fused vertebrae.

pygostyle
pygostyle     

Q

     

R

     

rachis

The outer portion of the shaft (central support) of the feather that supports the vanes

rachis
Canada Goose      Branta canadensis

radius

The smaller of paired bones in the middle section of the wing

radius
radius     

recurved

Curved upwards, as in the beak of an avocet

recurved
American Avocet      Recurvirostra americana

remiges

The flight feathers of the wing -- the primaries and secondaries combined

remiges
Greater Scaup      Aythya marila

retort nest

A globular nest with an entrance tunnel

retort nest
Lesser Masked Weaver      Ploceus intermedius

retrices

The major feathers of the tail

retrices
Red-tailed Hawk      Buteo jamaicensis

rhamphotheca

A horny sheath of keratin that covers the beak

rhamphotheca
rhampotheca     

rictal bristles

Stiff whisker-like feathers around the gape, most commonly found in aerial feeders, which presumably help to guide food into the mouth

rictal bristles
Tawny-breasted Flycatcher      Myiobius villosus

rump

The region between the back and the tail on the dorsal side of the bird

rump
Scarlet-rumped Cacique      Cacicus uropygialis

S

     

sacral vertebrae

Vertebrae just anterior to the caudal vertebrae, which are fused as part of the synsacrum

sacral vertebrae
sacral vertebrae     

salt gland

An organ for excreting excess salt found in seabirds, located above or in front of the eye

salt gland
salt gland     

sap well

A hole drilled in bark by a sapsucker that allows sap to collect. The woodpecker returns periodically to the well to drink the sap and eat any insects attracted to it.

sap well
Yellow-bellied Sapsucker      Sphyrapicus varius

scapula

The shoulder blade

scapula
scapula     

scapulars

Feathers at the base of the wing lying at the side of the back and often covering the folded wing

scapulars
Greater Flamingo      Phoenicopterus roseus

scavengers

Animals that feed on dead and decaying plants and animals

scavengers
White-backed Vulture      Gyps africanus

scleral ossicles

A ring of bones that supports the eye

scleral ossicles
scleral ossicles     

scrape

A shallow depression in the ground made by a bird to use as a nest

scrape
Least Tern      Sternula antillarum

secondaries

Flight feathers that attach to the ulna (forearm) inward from the primaries

secondaries
Steller's Eider      Polysticta stelleri

slots

Spaces between the primary feathers of certain birds such as vultures that allow individual feathers to act as airfoils and reduce turbulence

slots
Turkey Vulture      Cathartes aura

soaring

Sailing on outstretched wings without flapping or losing altitude

soaring
Bald Eagle      Haliaeetus leucocephalus

songs

Complex vocalizations communicating territoriality or advertising for a mate

songs
Blue-winged Warbler      Vermivora pinus

speculum

A patch of bright feathers on the secodaries of certain ducks' wings

speculum
Mallard      Anas platyrhynchos

spread-wing posture

Perched stance with wings outspread

spread-wing posture
Double-crested Cormorant      Phalacrocorax auritus

spur

A bony spike on the wing or tarsus certain birds, such as jacanas, screamers, pheasants, and spurfowl

spur
Yellow-necked Spurfowl      Francolinus leucoscepus

sternum

The breastbone - the site of attachment for the major flight muscles and the ribs

sternum
sternum     

structural colors

Coloration resulting from light scattering due to the physical structure of feathers

structural colors
Magnificent Hummingbird      Eugenes fulgens

subadult

A bird past the juvenile stage that has not reached maturity

subadult
Bald Eagle      Haliaeetus leucocephalus

sunning

Posturing to catch solar radiation

sunning
Groove-billed Ani      Crotophaga sulcirostris

supracoracoideus

The muscle that powers the upstroke of the wing. It attaches to the sternum and the humerus.

supracoracoideus
supracoracoideous     

surface diving

Diving beneath the water, starting at a swimming position

surface diving
Horned Grebe      Podiceps auritus

syndactyl feet

Feet with the outer and middle toes fused for most of the length, such as in kingfishers and hornbills

syndactyl feet
Rufous Hornbill      Buceros hydrocorax

syringeal muscles

Muscles that modulate the voice by controlling the shape of the syrinx (avian voice box)

syringeal muscles
syringeal muscles     

T

     

tarsometatarsus

The outermost of the three long leg bones in a bird. It is homologous to ankle and foot bones of mammals.

tarsometatarsus
tarsometatarsus     

tarsus

Alternate name for the tarsometatarsus and also for that region of the leg

tarsus
Herring Gull      Larus argentatus

temporal fovea

An area of concentrated receptor cells in the retina toward the side of the head. It increases the depth perception in hawks, terns parrots, swallows and doves.

temporal fovea
temporal fovea     

territory

A space defended by a bird for the exclusive use

territory
Yellow-headed Blackbird      Xanthocephalus xanthocephalus

tibiotarsus

The middle bone of the three long bones of the leg, familiar to us as the drumstick

tibiotarsus
tibiotarsus     

torpor

A state of severely decreased metabolism, in which the body temperature of a bird is reduced and energy is conserved

torpor
torpor     

totipalmate

All four toes joined in a web; typical of pelicans, boobies, and cormorants

totipalmate
Blue-footed Booby      Sula nebouxii

tubular nares

A cylindrical extension of the nostrils in Procelliform seabirds, which helps to expel briny secretions of the salt gland

tubular nares
Southern Giant-Petrel      Macronectes giganteus

tympanic membrane

The eardrum

tympanic membrane
Double-wattled Cassowary      Casuafalcorius casuarius

U

     

ulna

Larger of paired bones between the humerus and the wrist, to which secondaries attach

ulna
ulna     

undertail coverts

The ventral feathers covering the base of the retrices

undertail coverts
Dusky Grouse      Dendragapus obscurus

underwing coverts

The ventral feathers covering the base of the remiges

underwing coverts
Willet      Catoptrophorus semipalmatus

uppertail coverts

The dorsal feathers covering the base of the retrices

uppertail coverts
Mew Gull      Larus canus

uric acid

A pasty white excretory product equivalent to urine, but less wasteful of water

uric acid
Atlantic Puffin      Fratercula arctica

uropygial gland

The preen gland located near the dorsal base of the tail, which secretes oily substances to protect the feathers

uropygial gland
American Redstart      Setophaga ruticilla

V

     

vane

The sides of the feather extending from the shaft

vane
Wood Stork      Mycteria americana

vent

The opening of the cloaca

vent
Chipping Sparrow      Spizella passerina

vitelline membrane

The thin layered structure around the egg yolk, which following fertilization forms a barrier to new spermatozoa

vitelline membrane
vitelline membrane     

W

     

wing bar

A stripe formed on the wing by light-colored tips to coverts

wing bar
Blackpoll Warbler      Setophaga striata

wing spurs

Sharp bony projections on the wings of certain birds such as jacanas, screamers and some plovers

wing spurs
Horned Screamer      Anhima cornuta

wingspread

The distance from one wingtip to the other

wingspread
Bald Eagle      Haliaeetus leucocephalus

wrist

The bend in the wing at the base of the primary feathers where the outmost segment of the wing starts--rusty-colored in this Great Blue Heron

wrist
Great Blue Heron      Ardea herodias

X

     

Y

     

yolk

The yellow part of the egg which feeds the developing embryo. These men are cooking an ostrich egg.

yolk
Common Ostrich      Struthio camelus

Z

     

zygodactyl feet

A foot in which the hallux and fourth toe face backward and second and third to face forward, as in woodpeckers and parrots

zygodactyl feet
Checker-throated Woodpecker      Picus mentalis