222 GEOLOGICAL SURVEY OF CANADA. 
CXXII. CIRCUS LaAckEpEDE. 1801. 
331. Marsh Hawk. Marsh Harrier. 
Circus hudsontus (LINN.) VIEILL. 1807. 
Rare in Newfoundland. Only once seen at Cow Head. (Reeks.) 
Audubon saw it in Labrador. (Packard.) The following are our 
most northern references to this bird: Moose Factory, James 
Bay, where Spreadborough saw it on June 11th, 1896; Dr. 
Robert Bell records it from York Factory, Hudson Bay ; Clarke 
mentions its occurrence at Fort Churchill, on the west side of the 
Bay, and Richardson places its northern limit at Great Bear 
Lake, in Lat.65°. Bernard Ross, on the other hand, places its 
northern limit at Great Slave Lake, and says that it is scarce 
there. 
It is a summer resident and generally distributed in Prince 
Edward Island, Cape Breton Island, Nova Scotia, New Bruns- 
wick, Quebec and Ontario, and is very abundant throughout the 
whole prairie region, breeding as far north as Great Bear Lake. 
Rather rare in the mountains, but not uncommon in the Colum- 
bia Valley from Revelstoke south. Rather common westward, 
and becoming abundant at Sicamous and westward to Spence’s 
Bridge, B.C. (Macoun.) Abundant on the mainland of British 
Columbia at Sumas, Chilliwack, mouth of the Fraser, and east of 
the Coast Range. Partially migratory. A few are found through- 
out the winter in the neighbourhood of Ladner’s, near the 
mouth of the Fraser. (/annin.) These birds are numerous 
throughout northern Alaska during the migrations. They are 
seen frequently along the barren coast of Behring Sea, and have 
been recorded as rather uncommon in the interior. (JVe/son.) 
This bird appears to be a resident of the Yukon district only 
between the early part of April and late November. The species 
is a rare summer visitor on Attu Island. (Zurner.) Observed in 
winter at Lake Okanagan, B.C. (Brooks.) Noted at every stopping- 
place in British Columbia. Nowhere abundant. (/hoads.) I 
saw this species at Cape Blossom, Kotzebue Sound, Alaska, on 
two occasions. Marsh hawks were frequently noted at our 
winter camp on the Kowak the last of August. (Grinnell.) 
BREEDING Notes.—This species breeds frequently in the 
neighbourhood of Ottawa. Its nest is composed of dry grass 
