Theme: Feathered Homonyms - Three birds that can also be used as verbs. They are in all capitals to show the clues could have been the answer and the answers could have been the clues. The answers are all in the pattern of "verb + ONE'S + noun".
20A. DUCK : LOWER ONE'S HEAD
41A. CRANE : STRETCH ONE'S NECK
60A. QUAIL : LOSE ONE'S NERVE
Argyle here. Bird is the Word(1:06) Kevin used a similar gimmick back in 2010. Link He gave us another puzzle last year; maybe he can squeeze in two this year. I'd like that. A grid spanner, no cheater squares, and just a 'Q' short of a pangram.
Across:
1. Fashionable : CHIC. A young quail is called a chick.
5. __ Blanc, the Alps' highest peak : MONT
9. Wintry mess : SLUSH
14. Prolonged unconsciousness : COMA
15. Confess openly : AVOW
16. Like horror film music : EERIE
17. Practice boxing : SPAR
18. Luke Skywalker, e.g. : JEDI. The Force is with him.
19. Postal service symbol : EAGLE. Another bird.
23. The NFL's Cowboys : DALLAS
25. Energy : ZEST
26. Snake's warning : "SSS!"
27. "Can __ honest with you?" : I BE
28. 2011 World Series champs, on scoreboards : STL. St. Louis Cardinals.
30. Rogue : CAD
32. Ring loudly : PEAL
34. "Othello" villain : IAGO. He hates Othello and devises a plan to destroy the Moor by making him believe that his wife, Desdemona, is having an affair with his lieutenant, Michael Cassio(who we see in later in the week puzzles).
37. Fits of anger : RAGES
44. Actor Davis : OSSIE. He married actress Ruby Dee, you might remember. (You should.)
45. __-poly : ROLY. And here's a little ditty I'll bet you haven't heard. Clip(2:41) 49A. "__-haw!" : YEE
46. Yours, to Yves : À TOI
47. Presidents' Day mo. : FEB.
51. Any nonzero number divided by itself : ONE
52. Arafat's org. until 2004 : PLO. Palestine Liberation Organization. Yasser Arafat.
55. Remove, with "off" : TAKE
58. "Key Largo" 54-Down winner Claire : TREVOR, 54D. Hollywood award : OSCAR. She was in "Stagecoach" with John Wayne.
63. Not shortened, as a film : UNCUT
64. Suit to __ : A TEE
65. "Joy of Cooking" writer Rombauer : IRMA
68. Stiller's comedy partner : MEARA. Jerry Stiller and Anne Meara.
69. iPhone message : TEXT
70. Cowardly film beast played by 29-Down : LION, 29D. Actor Bert (see 70-Across) : LAHR
71. Swashbuckler Flynn : ERROL
72. Brother of Cain and Abel : SETH
73. "Ignore that editing change" : STET
Down:
1. IV amounts : CCs
2. "__ on Pop": Dr. Seuss : HOP
3. "Lay it on me!" : "I'M ALL EARS!"
4. Christmas song : CAROL
5. Like the Grand Canyon : MAJESTIC
6. Higher than : OVER
7. All-nighter pill : NODOZ. NoDoz® Alertness Aid Caffeine Caplets.
8. Bale binder : TWINE
9. Reel from a blow to the head : SEE STARS
10. Wife of Jacob : LEAH
11. Involuntary impulses : URGES
12. Eliot's "__ Marner" : SILAS
13. Obeys : HEEDS
21. Used to be : WAS
22. Upper-left PC key : ESC
23. Tippler, for short : DIPSO. Short for dipsomania, a compulsive desire to drink alcoholic beverages. And 42D. Abstain from alcohol : TEETOTAL
24. Helps with a heist : ABETS
31. Carvey or Delany : DANA. Twins? Not!
33. Explorer Ericson : LEIF
35. Moo __ gai pan : GOO
36. The "O" in SRO : ONLY
38. "Time to move on" : "GET OVER IT"
39. Money-saving, in product names : ECONO
40. Downhill racer : SKIER
43. Canines metaphorically exchanged for something desired : EYE TEETH. So named because they are directly below the eyes. I was expecting more.
48. Prohibit : BAN
50. Goof : ERR
52. Nom de __: pen name : PLUME
53. Solitary man : LONER
56. Grecian urn poet : KEATS
57. Cosmetics giant Lauder : ESTÉE
59. Lesser of two __ : EVILS
61. French franc successor : EURO
62. Deli counter call : NEXT
66. One of the Stooges : MOE
67. Picnic undesirable : ANT
Argyle