Birds of the World

COAST BIRDS
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WORLD BIRDS
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ANECDOTES

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TRAITS
 Ratites
 Tinamous
 Cracids/Galli
 Waterfowl
   Screamers
   Ducks

 Penguins
 Loons
 Grebes
 Procellarids
   Albatrosses
   Petrels
   Storm-Petrels

Totipalmate Swm

   Tropicbirds
   Gannets/Boobies
   Pelicans
   Cormorants
   Anhingas
   Frigatebirds

 
Waders
   Herons
   Ibises
   Storks  

 NW Vultures
 Flamingos
 Raptors
 Gruiformes
   Buttonquail
   Bustards
   Cranes
   Rails

 Shorebirds
   Sandgrouse
   Plovers
   Oystercatchers
   Stilts
   Sandpipers
   Gulls/Terns
   Auks

 Pigeons
 Parrots
 Turacos
 Cuckoos
 Owls
 Frogmouths
 Nightjars
 Swifts/Humbd
 Colies
 Coraciae

   Hornbills
   Hoopoes
   Trogons
   Rollers
   Kingfishers
   Bee-eaters
   Jacamars/Puffbd

 
Pici
   Honeyguides
   Woodpeckers
   Barbets/Toucans

PASSERINES
   NZ WRENS
   OW SUBOSC

      Broadbills
      Pittas

 NW SUBOSC
   NW Flycatchers

   Becards
   Cotingas
   Manakins
   Antbirds
   Ovenbirds
   Woodcreepers
   Antthrushes
   Tapaculos 

 OSCINES
 Lyre-/Scrub-birds
 Bowerbirds
 Aust. Wrens
 Honeyeaters
 Scrubwrens
 Aust. Robins
 Kinglets
 Shrikes
 Vireos
 Whistlers
 Corvids
 Birds-of-Paradse
 OW Orioles
 Cuckoo-shrikes
 Fantails
 Drongos
 Monarchs
 Bush-shrikes
 Wattle-eyes
 Vangas
 Waxwings
 Dippers
 Thrushes
 OW Flycatchers
 Starlings
 Mimids
 Nuthatches
 N Creepers
 Wrens
 Gnatcatchers
 Tits/Parids
 Larks
 Swallows
 Leaf-Warblers
 Bulbuls
 Cisticolas
 White-eyes
 Babblers
 OW Warblers
 Flowerpeckers
 Sunbirds
 OW Sparrows
 Accentors
 Pipits
 Estridids
 Weavers
 Whydahs
 9-prim. Oscines

   Fringillines
   Carduelines
   Hawaiian Honycrp
   NW Sparrows
   NW Warblers
   Tanagers
   Cardinals
   NW Blackbirds

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TRAITS
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Skeletal Features
  Palatal Structure
  External Nares
  Nasal Bones
  Columella
  Cervical Vertebrae
  Sternum

Legs and Feet
  Tarsometarsus
  Toes
  Feet
Development
Internal Features
  Supraorbital Gland
  Syrinx
  Intestinal Convolutions
  Intestinal Caeca
  Carotid Arteries
  Thigh Artery
Feathers and Skin
  Pterylosis
  Aftershaft
  Natal Down
  Number of Flight Feathers
  Wing Formula
  Fifth Secondary
  Powder Down
  Oil (Uropygial) Gland
  Rhamphotheca
Muscular Features
  Pelvic Musculature
  Deep Plantar Tendons
  Jaw Muscles
  Other Muscles
Other Features
   
 

Legs and Feet

 
  Tarsometarsus
  The middle of the three elements making up the hind limb is the tarsometarsus or, simply, "tarsus" (see Structure for a complete discussion of the leg in birds). This section is usually unfeathered (except grouse, owls, and some others). The podotheca (sheath) covering the tarsus is made up of epidermal scales. that may be
      scutellate - large scale-like segments
      reticulate - network of small, scale-like segments
      scutellate - reticulate - scutellate in front, reticulate behind
      scaleless - soft, skin cover (Chloroceryle, a kingfisher)
   The anterior horny sheath is called the acrotarsium, the posterior sheath is the planta.

   The shape of a cross-section through the tarsus is also charactgerized in song birds:
      latiplantar - rounded posteriorly (larks and a few others)
      acutiplantar - sharp-angled posteriorly (most oscines)

   Patterns of scuttelation have also been described:
      pycnaspidean - rear surface covered with small scales
      exaspidean - anterior segment extending across the lateral side of the tarsus
      endaspidean - scutellated segment extending across the medial surface
      holaspidian - rear surface covered with a single series of broad scales
      taxaspidian - rear surface covered y 2-3 series of small rectangular or hexagonal scales
      booted (ocreate) - scutes fuse into a single smooth sheath or boot (except at lower end)
      laminplantar - smooth undivided plantar surface, scutellate anterior surface

   Despite its popularity, the taxonomic value of scutellation is probably limited, even in passerines - it is too variable to indicate descent.
 
  Toes
  Typically birds have four toes (numbered from the hind toe or hallux - toe I - to the outer front toe - toe IV). They are numbered clockwise on the right foot and counterclockwise on the left).
   Most toes have one more phalange than their number (e.g., the hallux has two phananges, and toe IV has five). A few species have reduced these numbers.
   The Digital Formula (DF) is the number of phalanges (i.e., 2-3-4-5 in most birds)
   In most birds the hallux is functional and opposite the front toes (at the same level) - this hallux is incumbent. If the hallux is elevated it may not touch the ground.
   Larks have elongate hind toes (a terrestrial adaptation). In come species, the third toe's margin is pectinate (comb-like)
   Only the Ostrich has two toes - toes I and II have been lost (running leads to longer distal elements but no bird has reduced the toes to one as in horses).
   Some birds have 3 toes - these include other ratites and some tinamous, and representatives from a wide variety of families, including even one passerine (Paradoxornis). In most cases it is the hallux (first toe) that is lost. In several kingfishers, the second toe has been lost. Three toes are most often found in some running birds, scansorial birds, and divers that swim primarily with their wings.
 
  Feet
  In most birds, the hallux (first or great toe) is directed backwards and toes 2, 3, and 4 are directed forward. There are, however, several variations in the arrangement of toes:
   Anisodactyl - #1 back, 2, 3, 4 forward. Passerines.
   Zygodactyl - #1 and 4 back, 2 and 3 forward. Piciformes.
   Syndactyl - toes united. Todies and kingfishers.
   Heterodactyl - #1 and 2 back, 3 and 4 forward. Trogons.
   Pamprodactyl - all 4 toes forward.
   Adaptations for swimming include webs between all four toes (totipalmate) as in the Pelecaniformes and between the forward-directed toes (palmate) as in ducks and many water birds. Webs are reduced in many species that are more terrestrial than aquatic (passing through semipalmate on the way to unwebbed). In grebes, swimming is facilitated by lobes on the toes. Some species swim well with no obvious modification (e.g., dippers).
 
 

Development

  Various groups differ in developmental strategies; young may hatch feathered with their eyes open and may be independent immediately or after short stays with their parents (precocial young). Alternatively, they may hatch naked with, at most, a few tufts of down, and with their eyes closed (altricial young). They require brooding to be kept warm and food from their parents to grow and become independent. There is a spectrum of developmental strategies (see Development)
    In addition, young that leave the nest soon after hatching are said to be nidifugous and those that remain in the nest for an added period of development are said to be nidicolous. In general, precocial young are also nidifugous and altricial young are nidicolous. However, there are a number of adaptive quirks and specializations so that development patterns may be useful - they obviously have a genetic base.