Population studies . --One means of evalu- 

 ating the status and productivity of annual 

 waterfowl populations is the examination of 

 wings subnnitted to Bureau and cooperating 

 State biologists. By noting color, growth, 

 wear, and replacement of feathers, much 

 can be learned about the sex and age ratios 

 of various populations, the species composi- 

 tion of ducks in the hunters' bags, and 

 whether production of young birds was good 

 or poor. 



The duck wing collection-productivity 

 survey was expanded for the 1960-61 hunting 

 season to include the Atlantic and Missis- 

 sippi Flyways and, because of its uniquely 

 valuable contribution to an understanding of 

 waterfowl population dynamics, was further 

 expanded in the 1961-62 season to all four 

 flyw^ays. Analysis of wings received from 

 hunters in the Mississippi Flyway indicated 

 an increase in the importance of mallards 

 and a decrease in percentage of lesser 

 scaups in the hunters' bags in the 1960-61 

 season as compared with the previous sea- 

 son. In the 1960-61 season the percentage 

 of young birds was relatively high in the 

 populations of mallards, American 

 widgeons, green-winged teals, blue-winged 

 teals, pintails, wood ducks, ring-necked 

 ducks, and lesser scaups. Preliminary re- 

 sults from the 1961-62 wing collections 

 indicated that both the number and the 

 proportion of young ducks in the bag were 

 substantially below those for the 1960-61 

 season, suggesting reduced kill and poorer 

 production. 



The mail questionnaire survey of water- 

 fowl hunters was intensified so as to 

 achieve reliable kill data in States or 

 groups of States within a fly-way; previously 

 the results of these surveys were reliable 

 only for the flyway as a whole. Special 

 studies were made of bias that exists when 

 hunters report their kill and hunting activ- 

 ity in mail questionnaires, and of the 

 relations of season length and bag limits 

 to duck stamp sales and the waterfowl bag. 

 There appears to have been a significant 

 positive correlation between season length 

 and the sales of duck stamps during the 

 decade 1950-51 through 1959-60. 



Accomplishments of pre-hunting-season 

 banding of mallards and black ducks and of 

 the overall wood duck banding program 

 during 1959 and I960 were summarized in 

 progress reports (see Appendix C). 



During the summer of 1961 a study of 

 aerial inventory techniques applicable to 

 the Far North, or bush country, was initi- 

 ated. Simultaneously, ground studies were 

 begun in the Northwest Territories to learn 

 the factors affecting brood production and 

 its chronology under the conditions found 

 there. Information on the role of the bush 

 country in the production of species im- 

 portant in the hunting kill is needed, par- 

 ticularly during years of drought on the 

 prairies and as some indication of what 

 might result if further drainage occurs in 

 the pothole country. 



Through these and other studies the 

 Bureau is able to refine its procedures 

 for forecasting fall populations of water- 

 fowl and measuring the effects of various 

 hunting regulations on the level of the 

 kill. 



Waterfowl ecology . --Investigators from 

 the Denver Wildlife Research Center docu- 

 mented the effects on waterfowl habitat of 

 severe drought on study areas near Redvers, 

 Saskatchewan, Lousana, Alberta, and 

 Jamestown, North Dakota. On the Redvers 

 area the number of water areas on May 1, 

 1961, was 78 percent below the previous 

 9-year average and the number of breeding 

 pairs of ducks had decreased 86 percent. 

 Brood production dropped from a mean of 

 30 broods per square mile during the period 

 1952-60 and from a mean of 50 broods per 

 square mile in 1952 and 1953 to 3 broods 

 per square mile in 1961, A good start was 

 made in the Jamestown area in determining 

 basic water level-plant association rela- 

 tionships in and around potholes and the 

 use of various types of potholes by water- 

 fowl. The lack of suitable cover along the 

 receding shorelines was especially unfavor- 

 able for diving ducks and late-nesting dab- 

 blers, including the gadwall, blue-winged 

 teal, and shoveler. 



