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b. "Component individuals highly gregarious and generally more nervous 
than definitely breeding adults. "' 
c. “Both males and females present,'' At times the sex of certain individuals 
could be determined by the "quack" of the female or the reedy voice of the male. How- 
ever, the majority of the birds remained mute. In some instances, particularly in June, 
the colors of leg and bill aided in sex identification. The exact sex ratio could not be 
determined from observation alone but it is believed that females probably made up 
10 to 15 percent. 
d. "The maintenance of migratory characteristics (particularly in flight 
patterns).'' In normal daily routine flights, or when disturbed, the flocked birds 
generally flew as a group in a line or disorderly formation low to the water or at the 
most at a height of 50 to 200 feet. 
e. The birds appeared to exhibit a ''total lack of sexual activity or display." 
f. These blacks occur in numbers "sufficiently large to attract immediate 
attention" and that they seem to have "an affinity for saline marshes at least in Nova 
Scotia and Prince Edward Island."' 
g. "The combination of these several characteristics is sufficiently pro- 
nounced moreover, that the birds forming such concentrations are generally noticeably 
distinct from ‘other' blacks frequently the same marshes." 
h. The total numbers of blacks on the study area gradually reduced after 
July 1. The moulting of feathers became pronounced during this period. In early 
July, 1949, two adult, flightless females were banded in this area. Apparently a 
part of the birds moved to other areas during the moulting period. 
"Flightless blacks were tallied on the Kentville Sanctuary on and after July 7, 
and it would seem logical to explain the continuing decrease in the Grand Pre-Canard 
concentrations in late June and July in terms of a parallel build-up of moulting birds 
(on either study area or adjacent marshes). Post breeding females could thus be 
expected to increase late in the latter month and one of specimens collected on July 21 
may have belonged to such a classification. Both birds were moulting, but had not 
lost the power of flight at the time of collection. 
‘During the course of the study limited surveys of certain fresh water lakes 
and saline areas in the district adjacent to the Grand Pre-Canard were conducted. 
These involved censusing of the Black River lake system south of the study area and 
shoreline tallies at Scott's Bay on the Bay of Fundy; Delhaven and Medford beaches 
on Minas Basin. Waterfowl counts were entirely negligible on all of these locales. 
"Three days were spent on the saline marshes of the Annapolis River, an 
area essentially duplicating habitat conditions found on the Grand Pre“Canard. Although 
the concentrations of summering black ducks there were much smaller than those on the 
study area, the various characteristics outlined above applied with equal validity. Again 
the contrast between apparent breeding blacks and summering birds of same species was 
most striking. 
"Two specimens only were collected from sample groups, and these on July 21, 
when the period of study was nearly completed. Both were adult females, the ovary of 
one being apparently entirely atrophied, that of the second bird healthy but inactive. 
Cross sections of the ovary from the latter specimen are now in process of preparation 
for examination; blood smears from the abdominal cavity of both birds were also pre- 
pared for study. Liver cultures prepared from two specimens by Acadia University 
