It is believed that the nucleus of this sedentary group of 
birds is composed of individuals that in the early fall established 
wintering-ground behavior patterns. If bait traps are in operation, 
these birds monopolize them to the exclusion or partial exclusion of 
the transient population. Fall bait-trapping in areas where there are 
both wintering and transient populations does not, therefore, sample 
the over-all population in a representative manner. The trapping 
records will show a strong bias in favor of the wintering or sedentary 
population. 
In some areas, northern Lake Champlain for instance, a 
heavy "take" of black ducks in the vicinity of the banding station 
is not linked as strongly to a wintering population. This take may 
be influenced by -- 
a. Excessive shooting. 
b. Habitat from which it is hard to drive the birds. 
c. Natural habit of the birds to linger until late in 
the season. 
d. Trap baiting that induces the birds to remain in the 
area longer than is nornal. 
4. The time of movement from northern stations shows that 
some early flights of black ducks move quite long distances to southern 
areas, skipping intervening states. For example, some coastwise 
migrants from eastern Canada arrive in the Middle Atlantic area nearly 
a month earlier than birds from the same banding station arrive in 
southern New England. Populations from other areas fill in the gaps 
left. Sueh flights result in a leap-frog pattern of movement. Al- 
though important movements into the Middle Atlantie states take place 
about the middle of November, there are some groups such as those from 
Newfoundland that do not move in any appreciable numbers until December. 
Flights from northern interior points, particularly Ontario, 
disperse into the northern states early in October. During the latter 
part of October and early November the main southward movement of the 
Ontario black ducks gets under way, bringing the first of these birds 
into the South Atlantic states from 10 days to 3 weeks ahead of the 
northeastern blacks. Birds from these same bandings do not arrive on 
the Gulf Coast until the middle or latter part of December. Interior 
stations also appear to differ as to the time the important movements 
take place. 
| 5. Additional banding needed and studies that would furnish 
important information for use in interpreting banding data are: 
a. Ari expanded banding program on the southern wintering 
grounds, at least from New Jersey south and in the 
wintering areas of the Mississippi Valley, to deter- 
mine by indirect recoveries the origin of the winter 
populations on the wintering grounds would be necessary. 
hy = 
