weather conditions dictate. But a sizable portion probably remains as 
a unit, augmented from time to time by birds from the north, which soon 
establishes a wintering-ground behavior pattern. Hagar (1950) believes 
that for this group of birds, the establishment of winter territories 
or patterns is completed by December 5. This is probably true for some 
of the birds, though Massachusetts and points to the south usually 
receive important late flights of blacks from the north during December. 
The deduction that must follow is that in our coastal trapping 
we are banding primarily a sedentary group of birds, to the exclusion 
or partial exclusion of a migratory or transitory population that is 
taken by hunters but not taken in significant numbers in traps. The 
question is whether the monopolization of the bait traps by the more 
sedentary "trap-happy" population is of such magnitude that it prevents 
adequate sampling of birds stopping momentarily enroute to the south. 
Baiting certainly influences local waterfowl movements and in this in- 
stance it is reasonable to deduce that some bias, however, subtle, has 
influenced the data. It is conceivable that bias associated with the 
trapping might be as important as anything else in producing an inaccur- 
ate sampling of the overall population. If this is true, it is doubtful 
. that any amount of bait. trapping on certain wintering grounds in the 
northern coastal states will yield even reasonably accurate data on the 
extent or importance of migration through that particular point. 
There is additional evidence that along the coast many of the 
winter residents are actually banded during the fall. Indirect recov- 
eries at later seasons indicate relatively minor movements south of 
the banding station. 
Field observations tend to bear out the probability of trap 
selection. One who observes black ducks from day to day on particular 
tidal marshes readily differentiates between the old established flocks 
and new flocks which have just arrived. Usually the first birds to 
enter the traps are the banded ones that have acquired the trap habit. 
If there is any grain left in the trap, and if there has been no dis- 
turbance, some of the new arrivals may work up enough courage to join 
those in the trap. Probably it is the banded group that eats most of 
the grain placed in front of the trap to attract the birds. 
Another factor to be considered is that some black ducks from 
the north probably do not ordinarily stop in New England on their way 
south. Under the section "Time of Migration" it is shown that some of 
the far-northern blacks migrating along the coast may make only one or 
two stops enroute. Apparently some blacks fly nonstop from the Maritime 
Provinces or Maine to New Jersey. Others apparently work their way down 
the coast gradually. 
In contrast to the coastal bandings, the results of limited 
bandings on inland fresh-water areas show a stronger migration to 
southern areas in the flyway. Most of these stations are in the east- 
ern part of Massachugetts through which some of the northern flight 
birds migrate when they leave the coast for a brief trip across south- 
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