Literature Cited 
Bellrose, F. C. 
1944. Duck populations and kill, an evaluation of some 
waterfowl regulations in Illinois. Il]. Nat. Hist. Surv. 
Bul. No. 23 (2): 327-372. 
and Elizabeth Brown Chase. 
1950. Population losses in the mallard, black duck and blue- 
winged teal. I11. Nat. Hist. Surv. Biol. Notes No. 22 (2):1-27. 
Blouch, R. I., and G.A. Ammann. 
1952. Collection of biological material from hunters by use of 
postpaid envelopes. Mich. Dept. Cons. Unpubl. Game Div. Rept. 
2072: 1-6. 
Carney, Samuel M., and Aelred D. Geis. 
1960. Mallard age and sex determination from wings. J. Wildl. 
Memt., 24 (4): 372-381. 
Dow, S. A., Jr. 
1954. Anatomical specimen collection by prepaid envelope. 8th 
Ann. Conf., S. E. Assoc. Game and Fish Comm., 6 pp. 
Geis, Aelred D. 
1959. Annudl and shooting mortality estimates for the canvasback. 
J. Wildl. Mgmt.,23 (3): 253-261. 
» and Earl L. Atwood. 
1959. Reliability of the identification of bagged waterfowl in 
letters reporting band recoveries. Unpubl. Ms. Filed at 
Patuxent Wildlife Research Center, Laurel, Maryland. 
Hansen, Harry (Editor ) 
1959. The 1959 World Almanac and Book of Facts, New York World 
Telegram Corporation, N. Y. 896 pp. 
Martin, Fant W. 
1960. Analysis of black duck bandings--A progress report. 
Proceed. N. W. Wildl. Conf. 6 pp. 
Smith, Morton H. 
1960. Duck age ratios--Louisiana. Louisiana Dept. Wild Life and 
Fisheries Comm.,5 pp. mimeo. — 
Stewart, Robert E., Aelred D. Geis, and Charles D. Evans. 
1958. Distribution of populations and hunting kill of the 
canvasback. J. Wildl. Mgmt.,22 (4):333-370. 
-43- 
