Barclay, J. S. 1970. Ecological aspects of defensive behavior in breeding 

 Mallards and Black Ducks. Ph.D. thesis, Ohio State Univ. /Columbus , OH. 

 176 pp. 



Bellrose, F. C. and D. Crompton. 1970. Migration behavior of Mallard and 

 Black Ducks as determined by banding. 111. Nat. Hist. Soc. Bull. 30: 

 167-234. 



Bishop, R. A. and R. Marratt. 1970. Use of artificial nest baskets by Mal- 

 lard. J. Wildl. Manage. 34: 734-738. 



Bjarvall, A. 1970. Nest-site selection by the Mallard ( Anas platyrhynchos ) . 

 Viltrevy 7: 151-182. 



Drewien, R. C. and L. F. Fredrickson. 1970. High density Mallard nesting on 

 a South Dakota island. Wilson Bull. 82: 95-96. 



Ern, H. 1970. Nahrungsparasitismus und Futtertauchen bei der Stockente ( Anas 

 platyrhynchos ) am Bodensee als Reaktion auf Veranderungen im Nahrungsange- 

 bot. Vogelwarte 25: 334-336. [In German.] 



Jessen, R. L. 1970. Mallard population trends and hunting losses in Minne- 

 sota. J. Wildl. Manage. 34: 93-105. 



Lamont, T. G. , G. E. Bagley and W. L. Reicher. 1970. Residues of DDD and 



o,p DDT in Brown Pelican eggs and Mallard ducks. Bull. Environ. Contam. 

 Toxicol. 5: 231-236. 



Nellis, C. H. , J. J. Zohrer and D. W. Anderson. 1970. Mallard/Green-winged 

 Teal associations in southern Wisconsin. Wilson Bull. 82: 461-462. 



Prince, H. H. , P. B. Siegel and G. W. Cornwell. 1970. Inheritance of egg 

 product and juvenile growth in Mallards. Auk 87: 342-352. 



Snart, A. E. 1970. The effects of heat on Mallard embryos. M.S. thesis, 

 Univ. Florida/Gainesville, FL. 



Zohrer, J. J. 1970. Observations on premigratory movements of hand-reared 

 Mallards. Wilson Bull. 82: 323-324. 



1969 



Avitabile, A. 1969. Egg transportation by a female Mallard. Wilson Bull. 81: 

 331-332. 



Bjarvall, A. 1969. Unusual cases of re-nesting Mallards. Wilson Bull. 81: 

 94-96. 



Crichton, V. F. 1969. The helminths in the digestive tract of the Mallard and 

 Pintail in southern Manitoba. M.S. thesis, Univ. Manitoba/Winnipeg, MB. 

 121 pp. 



190 



