ORNITHOLOGY IN 1851. 
as far north as Groat Slave Lake, 60° 61' north. These birds gene- 
rally choose a rapid for the scene of their exploits, and commencing 
at the upper end, suffer themselves to float down with the current, 
fishing as they go with great success, particularly in the eddies. 
Their pouches are frequently so crammed with fish, that they can- 
not rise into the air until they have relieved themselves from the 
load ; and on the unexpected approach of a canoe, they stoop down, 
and drawing the bill between their legs, turn out the fish. They 
seem to be unable to accomplish this feat when swimming, so that 
then they are easily overtaken and may be caught alive, or killed 
with the blow of a paddle. If they are near the beach when danger 
threatens, they will land to get rid of the fish more quickly. The 
Black-bellied Tern, Hydrochelidon nigra , ranges northward to the 
upper parts of the Mackenzie, and the Sterna cayana is common 
onwards to beyond the Arctic circle. 
Sir John’s opinion as to the American Cranes, at variance with 
that of Audubon, is also of importance. Mr. Rae killed specimens 
of the Brown Crane, Grus canadensis , “ but though I concede that 
the young of the latter are grey , I think that the brown species is 
distinct ; first, because it is generally of larger dimensions than the 
white bird ; and secondly, because it breeds on the lower part of the 
Mackenzie, and near the Arctic coasts, where the G. americana is 
unknown. As far as I could ascertain, the latter bird does not go 
much farther north than the Great Slave Lake.” 
At Big Island, at the western outlet of Great Slave Lake, the 
Barking Crow, Corvus americanus , was met with for the last time. 
In the Fauna Boreali Americana I have stated, that it does not 
range beyond the 55° ; but more correct information, received ou 
the present voyage, enables me to carry its northern limit on to the 
61°. “ It becomes rare before it ceases altogether to be seen.” 
“ The river of the mountains marks the northern limit of the 
American Magpie, Say’s Grouse, and the White Crane, Grus ameri- 
cana .” 
Still farther north we have these observations on the Ornithology 
of Great Slave Lake and the Mackenzie: “ The general aspect of 
the forest does not alter in the descent of the Mackenzie. There is, 
in fact, notwithstanding the near neighbourhood of the Arctic Circle, 
no want of flowering plants to engage the attention of a student 
of nature ; and many of the feathered inhabitants of the district 
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