This is for part of my drawing assignment. We were asked to illustrate and explain a birds wing on one page. I kind of rushed through this tonight. This is a draft and I will be hand drawing it again later today after I have rested, and I may add some more examples of different types of wings in motion ect.
The three points I cant express enough when illustrating wings though are –

1) Feather placement! First primary goes UNDER the next feather from top view. First primary goes OVER second feather on underside view.
2) A bird wing is like a human arm in allot of ways. Make sure you have the correct amount of bends- joints. If in doubt try posing your arm for ideas!
3) When folded, primaries tuck under the secondaries not the other way around!

Sourced from many places, including illustrations and photos online, books, a dried wing I own and my parrot NC. It’s probably not the most amazing ref (and there may be mistakes atm *so tired* XD). But hopefully this will be of use to someone!

*Edit* -
Here are some usefull photos and illustrated refs that I have collected for my study. I am sure they will be of great help for those who wish to draw some wingsssss!

Bones -
http://academic.emporia.edu/sievert...../birdbody2.JPG
http://www.flickr.com/photos/212794.....00/4301540128/
http://www.flickr.com/photos/cyborg.....zy/1455596431/


Feather illustrations -
http://featherfancy.com/images/wing_clips.gif
http://www.twitt.org/LordsBird03.jpg
http://upload.wikimedia.org/wikiped.....ngfeathers.png
http://raptorrehab.files.wordpress......ng_by_lily.jpg (This one again shows the vital placement of the primary and secondaries!)

Photos - (Seriously, look through flickr. You will find some awesome bird wing refs there!)

http://www.flickr.com/photos/jrniko.....n/photostream/

http://www.flickr.com/photos/sarahb.....le1/144753429/

http://susty.com/image/legend-of-pa.....prey-photo.jpg

http://www.dorlingkindersley-uk.co......ge_bird003.jpg

http://www.flickr.com/photos/daaynos/449276506/

http://www.flickr.com/photos/593037.....00/3953343294/

http://www.flickr.com/photos/320810.....07/3607434096/

http://www.flickr.com/photos/1stlady/644398880/

http://www.flickr.com/photos/500594.....N00/300765724/

http://www.flickr.com/photos/538983.....00/2211304917/

2 really good tutorials (much more in depth) others have made! -

http://unkraut.deviantart.com/art/Bird-s-wing-anatomy-30580013?q=boost%3Apopular%20bird%20wing%20tutorial&qo=5

http://theantimonyelement.deviantart.com/art/Bird-Wing-Tutorial-150844565?q=boost%3Apopular%20bird%20wing%20tutorial&qo=0