Avian (Bird) Anatomy – Images of Feathers & Skin by Jeannine Miesle

Main Article: Avian Medical Terms / Health & Diseases by Jeannine Miesle, MA, Allied Member, Association of Avian Veterinarians …

Avian Anatomy Image Gallery (NOTE: Some of the images / illustrations on this and linked pages may be too graphic for young audiences. We recommend parental supervision and approval.)


http://www.bing.com/images/search?q=feather+tracts+in+birds&view=detailv2&&&id=938C721BF3E8CF3AD68F3F78F47 AFA657C5D3EC8&selectedIndex=0&ccid=1%2fSY7eP%2b&simid=608039426881686875&thid=JN.NwoXUpGclwD6iVP 1LMt77g&ajaxhist=0

Feather Tracts

Wing AnatomyPrimary and secondary feathering, feather numbering of wing

Bird feathers http://www.earthlife.net/birds/images/anatomy/wing.gif

Numbering of Wing and Tail feathers https://nusavifauna.files.wordpress.com/2012/08/bird_anatomy_1.jpeg

Bird Wing Anatomy

Leading edge of wingLeading edge of wing http://www.bing.com/images/search?q=leading+edge+of+bird+wing&view=detailv2&&&id=A04C6A6D17F24925EF2456B 211673B6D55097953&selectedIndex=149&ccid=DvCZsmAL&simid=608021164690639938&thid=JN.fwDqwXUM5Yjwv% 2f1tqk5kpg&ajaxhist=0

Inner wing feathers http://www.bing.com/images/search?q=inner+wing+of+bird&view=detailv2&&&id=0FD8F69BAAB720282CD2A720FABA5 67 9CBF4A077C0&selectedIndex=13&ccid=FmkYx6xG&simid=608005019906083412&thid=JN.jBWBLxcPRox7QiumBHI0V g&ajaxhist=0

Inner Wing Feathers

Wing feathers http://www.bing.com/images/search?q=bird+wing+feathers&view=detailv2&&&id=56E04B780B39624579A0450C417056 A2ECD277D6&selectedIndex=1&ccid=bFNrLqrW&simid=608027461098997025&thid=JN.ElzuSQDr7G%2faSRg6vDksH A&ajaxhist=0

Wing Feathers

Brood patch http://www.bing.com/images/search?q=brood+patch&view=detailv2&&&id=9216B471633D5A8D9BA7D618C4 24B4E1A4BFFB07&selectedIndex=13&ccid=un7L9bao&simid=608015834619776290&thid=JN.6rL5KMAnJgI3 CDrFvr%2b6QQ&ajaxhist=0

Brood Patch

Blood Feathers and feather sheaths. Blood feather and feather sheath http://www.bing.com/images/search?q=blood+feather&view=detailv2&&qpvt=blood+feather&id=A6D4730BD3C2500F8C9 C989B50D6E7D27C37FF5F&selectedIndex=5&ccid=C48qBHE/&simid=608044821348289044&thid=JN.u1jHpa

Blood Feathers and feather sheaths. Blood feather and feather sheath

Recursive Crest http://www.bing.com/images/search?q=bird+crest&view=detailv2&&&id=F727ED95B26BB7654CF57DF76D1E 68 DCC98091F1BD&selectedIndex=163&ccid=Vl1q/Gf+&simid=608031330837335601&thid=HN.6080313308373 3

Recursive Crest


Recumbent CrestRecumbent Crest http://www.bing.com/images/search?q=bird+glottis&view=detailv2&&&id=19F36453DEA8572015FDD0ED95C 7EAEC41AE09CD&selectedIndex=0&ccid=ogpWS2Ug&simid=608004298336109970&thid=JN.DAtJUsry08c% 2fjgBQEtA7%2fw&ajaxhist=0

Feather anatomy from Drs. Foster and Smith

Parts of the feather:

  • Calamus: Central shaft at the base which extends under the skin into the feather follicle.
  • Rachis (scapus or quill) feather shaft above the calamus that holds the barbs.
  • Vane: part of the feather that holds the barbs
  • Barbs: filaments on either side of rachis, extend at approximately 45 degree angle from rachis
  • Barbules and barbettes (hooklets): microscopic filaments that attach to each other, forming a tight, smooth surface. Bird keeps them attached during preening.
  • After-feathers (hypopenae): small tuft of feather at the base of the rachis.
  • Downy Barbs: barbs that are not hooked together at base of rachis.
  • Pennaceous feathers: those with barbules and hooklets, as in quill pen.
  • Plumaceous: down feathers, without rachis and quill
  • Distal Umbilicus: the base of the vane
  • Proximal or inferior umbilicus: the end of the calamus that is attached to the follicle
  • Pterylae: feather tracts
  • Apteria: featherless areas between the pterylae

Types of Feathers

Flight FeatherTypes of feathers: each type has a different function

Contour feathers:

  • Cover most of the surface of the bird, providing a smooth appearance. 69  Protect the bird from sun, wind, rain, and injury.
  • Brightly colored and have different color patterns. 
  • Divided into flight feathers and those that cover the body.

Flight feathers: Wing and tail feathers

Remiges: flight feathers of the wing, separated into three groups:

  • Primaries: long feathers attached to the manus (metacarpal [wrist] and phalangeal [finger] bones) at the far end of the wing Responsible for forward thrust. There are usually 10 primaries, numbered from the inside out.
  • Secondaries: attached to the ulna, a bone in the middle of the wing, Supply “lift” and are used in courtship displays. There are usually 10-14 secondaries, numbered from the outside in.
  • Tertiaries: flight feathers closest to the body; attached to the humorus (long bone)

Retrices: tail feathers; act as brakes and a rudder, Control the orientation of the flight. Most birds have 12 tail feathers, numbered from the center out

Coverts: Smaller feathers that cover the bases of the flight feathers There are several layers of contour coverts on the wing and ear.

FiloplumesDown feathers

  • Small, soft, fluffy, and are found under the contour feathers.
  • Plumaceous, and have many non-interlocking barbs, 
  • Lacking the barbules and hooklets seen in contour and flight feathers.
  • This makes it possible for them to trap air in an insulating layer next to the skin, protecting the bird from heat and cold. Powder down feathers: give off powder
  • When the sheaths or barbs of these feathers disintegrate, they form a fine keratin powder, which the bird can spread over its feathers as a water-proofing agent.
  • The powder assists in cleaning as the bird preens.
  • The absence of powder down in birds such as cockatoos and African greys can be a sign of disease, including Psittacine Beak and Feather Disease.


  • Fine, hair-like feathers with a long shaft, and only a few barbs at their tips.
  • Located along all the pyterlae.
  • Although their function is not well understood, they are thought to have a sensory function, possibly adjusting the position of the flight feathers in response to air pressure.

Semiplumes and Bristle FeathersSemiplumes:

  • Provide form, aerodynamics, and insulation.
  • Play a role in courtship displays.
  • Have a large rachis, but loose (plumaceous) vanes.
  • They may occur along with contour feathers or in separate pterylae.

Bristle feathers:

  • Have a stiff rachis with only a few barbs at the base.
  • Usually found on the head (around the eyelids, nares, and mouth).
  • Have both a sensory and protective function. 

Feather growth

Follicles: specialized areas in the skin where feathers develop.

Blood feather:

  • A developing feather that has an artery and vein that extend up through the shaft and nourish the feather.
  • Has a larger quill (calamus) than a mature feather  Is covered with a waxy keratin sheath that protects it while it grows
  • The sheath is removed by the bird when the feather is mature, after the blood supply recedes

Shaft color:

  • Will be purple while blood is still nourishing the feather.
  • Will change to white when blood recedes back into the body after the feather has grown out.


  • A bird will molt out or lose all of its feathers about once a year.
  • It takes months to lose and replace feathers, allowing the bird to continue to fly
  • The adult bird will gradually replace all of its feathers during a molt  This is so the bird can continue to fly and maintain body temperature
  • A molt usually takes place after breeding season.
  • reeding season is triggered by the longer photoperiod in the spring, so molting occurs during the summer; wild birds develop brighter plumage

Erector and depressor muscles in skin http://pubs.sciepub.com/materials/1/2/2/figs

Erector and depressor muscles in skin

Feather duster disease http://www.bing.com/images/search?q=feather+duster+disease&view=detailv2&&&id=3DFA1B549B49DFCC6FE3C08012 5DB9BA26BDA726&selectedIndex=0&ccid=CvNnRnV%2b&simid=608033869188628558&thid=JN.Xbn6YFGaXLHaxsTG F9CRNg&ajaxhist=0

Feather duster disease

Feather Cyst http://www.bing.com/images/search?q=bird+glottis&view=detailv2&&&id=19F36453DE A8572015FDD0ED95C7EAEC41AE09CD&selectedIndex=0&ccid=ogpWS2Ug&simid=608004298336109970& thid=JN.DAtJUsry08c%2fjgBQEtA7%2fw&ajaxhist=0 

Feather Cyst


Cross section of a bird’s skin http://people.eku.edu/ritchisong/avian_integument.htm

Cross section of a bird’s skin

Dermatitis (Miesle)



Photo of author

Jeannine Miesle

Jeannine Miesle, M.A., M.Ed, Allied Member, Association of Avian Veterinarians is an important contributor to Beauty of Birds. Jeannine has done considerable writing, proofreading and editing for journals and newsletters over the years. She had taught English and music in the schools and presently is an organist at Bethany Church in West Chester, Ohio. She also administrates a Facebook group, The Science of Avian Health.

Jeannine takes in rescued cockatiels and presently has twelve birds. When they come to her they remain as part of her flock.