Blue, snow, and lohite- fronted goose prodiw- 

 f/on. — Since blue, snow, nnd white-fronted geese 

 nest in inaccessible areas near to and north of the 

 Arctic Circle, it is difficult to conduct breeding- 

 ground studies of their productivity. However, 

 the ditl'ercnce in plumage between adults and 

 young, and (lie liirds" liabil of traveling in family 

 irroups, make it p()ssil)]e to determine productivity 

 with a high degree of accui-acy through wintering- 

 ground surveys. Records so obtained provide, 

 over a period of yeai's. a continuous picture of the 

 population dynamics of tlie species, and form the 

 basis for a progressive management program. 

 Sui-veys during the winter of 1961-62 showed gen- 

 erally poor nesting success, with 7 percent young 

 for blue geese, 20 percent for lesser snow geese, 1.2 

 percent for greater snow geese, and -JS percent foi- 

 white-fronted geese. Preliminary results of sur- 

 veys during the winter of 1962-68 showed better 

 success, with corresponding percentages of 31, 29, 

 28, and 38. 



Wood du/;ks.— Studies of wood ducks on Pool 10 

 of habitat in the marshes and swamps of Pool 10. 

 of the Upper Mississippi National Wildlife Ref- 

 uge by the Iowa Unit indicated that 65 percent of 

 an estimated 470 pairs nested off the Refuge, 

 mostly on tributary streams or on the blufi's. Nest- 

 ing density was about three pairs per square mile 

 of habitat in the marshes and swamps of Pool 10. 



A special project was conducted by the Mas- 

 sachusetts Unit on techniques for aging wood ducks 

 in the fall. Adults and juveniles of a captive 

 colony of known-age birds were periodically ex- 

 amined. The most reliable age criterion ])roved to 

 l)e the metallic blue color of the middle wing 

 coverts of the juveniles, which persisted until 

 April, well after the gunning season. A detailed 

 description of the age ci'iteria developed was for- 

 warded to the Patuxent Wildlife Research Center 

 and the findings helped to confirm techniques being 

 used Ijy research personnel handling waterfowl 



^^m- ,:. 



Blue and snow geese, nesting near to and north of the Arctic Circle, are difficult to study on their nesting 

 grounds. The difference in coloration between adults and young, and the species' habit of flying in family groups, 

 however, permit easy and accurate determination of nesting success and productivity. Left to right, adult blue, 

 adult lesser snow, first-winter young lesser snow, and first-winter young blue, in "sooty" and "pearl-gray" phases. 

 (Photo by John J. Lynch) 



14 



