• holarctic
• large, diving, duck-like aquatic birds
• males and females appear the same, both with alternate and basic plumage
• plumage heavy and waterproof
• long, straight, chisel-like or spear-shaped bill; short neck
  
• foot-propelled diving birds - legs far back on body (like Podicipeds; excellent for swimming and diving, difficult for walking on land)
• palmate feet - 3 front toes fully webbed
• eat mostly fish
• breed in fresh water, winter on ocean
• long-lived; monogamous; carry young on back

• worldwide
• small to medium-sized diving aquatic birds
• dense plumage; feathers waterproof due to oily secretions
• most have chisel-like bill, except Pied-billed Grebe
• foot-propelled diving birds - legs far back on body (like loons; excellent for swimming and diving, difficult for walking on land)
• lobate feet with flattened nails; reduced tail
• eat fish
  
• eat own feathers! the feathers trap fish bones which are then regurgitated
• have floating nests; carry young on backs

• found in all oceans; more common in southern hemisphere
• seabirds, well-adapted for flight - many with long, thin wings, held stiffly for soaring
• plumage dense and waterproof
• gland in orbit for concentrating and excreting salt
  
• tube-nosed (tubular nostrils) - well-developed sense of smell
• hooked bill
• 3 front toes webbed
• single egg w/ long incubation period; long-lived

• small to large, gull-like seabirds

• very large waterbirds

• distinctive bill with large, expandable pouch - gular sac; dive and scoop to get prey
• gregarious; also cooperate to herd fish

• large seabirds with pointed wings and tail
• chisel-like bill with small, mostly feathered gular sac

• worldwide distribution
• long-legged and long-necked for wading in shallow water
• very diverse bill size/shape (dependent on fishing style)
• often breed colonially

• largest family
• medium to large wading birds; slender body
• specialized vertebrae allow folding neck into "S" and spearing prey
• long, spear-shaped bills (eat fish, frogs)
• have powderdowns which aid in feather care
• mostly colonial breeders

• medium to large wading birds
  
• long bill – decurved (Ibises) or broadly spatulate (Spoonbills)
• front toes webbed at base
• highly gregarious

• large to very large soaring scavengers
• bare skin on head and neck
• perforated nostrils
• lack syrinx
• often seen sunning with spread wings

Anseriformes - Waterfowl - (Swans, Geese, Ducks, Screamers)

• worldwide
• aquatic/semi-aquatic birds that both swim and fly well
• short-legged, long-necked
  
• feathered oil-gland
• precocial young

• medium to very large waterfowl
• depressed bill - flat, wide, and rounded at end - with lamellate or serrate edges
• legs short with palmate feet (3 toes webbed)
• highly social during non-breeding season

• worldwide distribution
• diurnal birds of prey
• strong fliers
• short, strongly hooked bills
  
• strong feet with grasping talons
• females usually larger than male
• semi-precocial young (downy, eyes open, but dependent for long time)

• wings broad and rounded
• cere and eye-ring bare - often brightly colored

• wings long and pointed
  
• cere and eye-ring bare

• worldwide distribution
• medium to large fowl-like birds; often cryptically colored
• primarily terrestrial birds with strong legs and heavy feet well-developed for walking
• hind toe always present, often raised above the ground
• wings short and rounded
• bill short and conical w/ curved culmen (downcurved bill with overlapping tip)
• large muscular gizzard
• large clutches; precocial young

Gruiformes (Cranes, Rails, Coots, and allies) 

• worldwide
• very diverse - grouped together based on shared features of palate and skeleton
• many are aquatic; many are shy, hard-to-see species
• no crop; most have oil gland
• fly with neck straight
• primarily precocial young

• shy, mostly solitary, small to medium-sized waterbirds
• body laterally compressed 
• bill variable, usually slightly decurved
• short tail

• worldwide
• very diverse; many bear no outward resemblance to each other
• all have distinct palate, syringeal muscles, and vertebral column
• waders, swimmers, divers (all water birds or derived from water birds)

• small to large shorebirds
• wading birds
• bill often long and slender, not compressed near tip
• long toes

• small to medium-sized shorebirds
• wading birds
• upright posture with rounded head and short, thick neck
• bill relatively short and compressed near tip (stubby bills, often swollen at tip)
• broken-wing display when nest or young approached

• small to large waterbirds
• strong fliers - wings long and pointed
• palmate feet (webbed)
• often colonial
• opportunistic omnivores (except terns and skimmers which eat mostly fish)
• many well-adapted to humans and their constructs (dumps)

          Haematopodidae – Oystercatchers

• worldwide near water
• plumage black or black-and-white
• bill red, long, and laterally compressed
• short neck; wings long and pointed; short tail
  
• stout pink legs and feet; 3 toes slightly webbed
• feed mostly on molluscs
• sexes similar; monogamous; 2-4 eggs in a scrape nest; biparental care

          Recurvirostridae – Avocets and Stilts

• nearly worldwide near water
• terrestrial waders; swim readily
• plumage usually white below with black and (sometimes) cinnamon
  above
• bill long and slender, recurved in avocets
• small head; long neck; wings long and pointed; short tail
• legs long and slender; feet webbed in avocets; hallux vestigial
• feed principally on invertebrates and/or aquatic vertebrates
• sexes similar; monogamous; colonial; usually 4 eggs; biparental care

• worldwide
• plump-bodies with small heads, short bills, and short legs
• large crop that produces crop milk (for offspring)
• clutch size = 2; biparental care

• long, decurved bill
• two toes forward, two toes back, with outer hind toe reversible (zygodactyl)
• several species parasitic - all Old World and 3 New World species, none in USA

• worldwide
• slender; long-tailed (usually); 8-10 (instead of 10-14) rectrices
• bill usually thin and decurved
• zygodactyl feet
• Old World species are parasitic

• worldwide
• mostly nocturnal birds of prey; soft specialized plumage muffles sound; cryptically colored
• large heads with facial disks that concentrate sound and increase hearing sensitivity
• asymmetrical ear openings in some - improves localization ability
• large eyes fixed - can turn head from side to side (up to 270 degrees)
• specialized telescopic vision
• small heavily decurved bills
• strong feet with sharp talons; zygodactyl toes; outer toe can be reversed
• often feathered legs and toes
• regurgitate pellets (undigestible material, such as bones, etc.)
• female often larger than male

• heart-shaped facial disk
• legs longer than tail; tarsi feathered; toes bare

• rounded facial disk
• legs shorter than tail; tarsi feathered; toes feathered in some species

• worldwide
• nocturnal or crepuscular
• medium-sized
• soft plumage, usually cryptic
• long, pointed wings; flight strong but erratic
• small bill with wide gape; often long, stiff rictal bristles surrounding bill
• short, weak legs and feet
• clutch size = 1 or 2

• catch insects on the fly
• comb on middle claw

• small or very small birds with extremely short legs and tiny, weak feet
• very accomplished fliers
• very small humerus; 10 long primaries, short secondaries
• clutch size = 1 or 2

• worldwide
• small to medium-sized aerial foragers
• body streamlined; spend most of time in the air
• tiny bill; insectivores
• sexually monomorphic
• gregarious; nest on sides of cliffs, in caves, hollow trees, and chimneys

• New World
• smallest birds
• very agile fliers; sternum and flight muscles large; wing rotates at shoulder joint
• long, slender, pointed bill (terete); nectar-feeders; hover when foraging
• sexually dimorphic; males have irridescent feathers
• solitary

• worldwide
• mostly stocky birds with large heads and prominent bills; carnivorous
• conspicuous; brightly colored; many gregarious and noisy
• small syndactyl feet (two toes, 2 and 3, partially fused)
• hole-nesters; altricial young; often cooperative breeders

• often crested
• stout body and short neck
• wings short and rounded

• worldwide, excluding Australasia
• very diverse bill shapes; long, barb-tipped tongues
• drill into wood for food and to excavate nest cavities
• zygodactyl feet; unique arrangement of tendons in toes
• stiff, pointed rectrices
• cavity nesters; altricial young
• flight often undulating

• strong, chisel-like bill
• stiff, pointed rectrices (tail feathers)

• anisodactyl feet (three toes forward, one toe back)
• distinctive palate
• altricial young

• small to medium-sized songbirds
• suboscine – song poorly developed
• often drab color
• often forage by aerial-hawking
• bill typically broad and flat with surrounding rictal bristles
• often edge species

• medium-sized, predatory birds
• large head with strong, hooked bill
• strong legs with sharp claws
• often cache food on barbed wire or thorns

• small birds
• bigger heads and thicker bills than warblers
• heavy bill, slightly hooked or notched
• forage by gleaning from foliage

• medium to the largest passerines
• bristles pointing forward over the nares
• bold, noisy, and gregarious
• often nest predators
• intelligent; cache food

• small to medium-sized passerines
• pointed, slightly decurved bill
• fairly long legs
• walk rather than hop

• small to medium-sized birds
• strong fliers; wings very long and pointed; forage by aerial hawking
• small bill with rictal bristles
• some are colonial nesters

• small, sociable, and energetic birds
• short, stout bill
• cache food
• in winter, form mixed-species flocks

• small, stocky forest birds
• climb tree trunks; forage by gleaning
• only birds that move down trunk head first
• bill thin and pointed, typically straight
• tail short and square

• small forest birds
• climb trees, like nuthatches, but head up
• slender, pointed, decurved bill
• long, stiff, pointed retrices

• small to medium-sized, chunky, active birds
• slender bill, often decurved
• tail usually short
• several species often have tail upright and cocked
• often found in shrubby habitat

• very small, very active birds – somewhat fidgety
• slender bills
• sexually dimorphic

• small to medium-sized birds
• constantly in motion
• slender bills

• small to medium-sized birds
• chunky body, upright posture
• often hop on ground when foraging
• straight bill, not pointed
• several species have melodious songs
• blue eggs

• slender, medium-sized birds with long tails
• tail often cocked, i.e. higher than line of body, when standing
• versatile singers; mimic other birds

• medium-sized, stocky birds
• short, square tail
• gregarious
• some are mimics

• small to medium-sized birds
• chunky body, but slimmer than thrushes
• some species bob tail

• medium-sized birds with prominent head crest
• plump body; short, thick bill; medium to long, square tail
• highly gregarious frugivores

• small to medium-sized birds
• many species brightly colored; most sexually dimorphic
• slender, pointed bills; rounded tails
• mainly insectivores; often glean from foliage
• often complex songs

• medium-sized forest birds with stout bills
• sexually dimorphic; male more brilliant than female

• small to medium-sized birds
• often brown and streaked
• short, pointed, conical bills
• forage mostly on the ground
• often seen in shrubs

• medium-sized to large birds
• sexually dimorphic
• bills with angulated commisure
  
• often edge species

• medium-sized to large birds
• sexually dimorphic; male usually larger
• straight, sharply pointed bills

• small to medium-sized birds
• sexually dimorphic
• stout, conical bill (crossed in 2 species)
• emarginate tail
• undulating, fast flight
• long, complex songs
• often forest birds

• small birds with stout, conical bill
• no well-developed song; often repeat single elements