82 The Ottawa Naturalist. [November 



Horned Grebe Colymbus auritus. 



Winters commonly on Okanagan Lake. 

 Red-billed Grebe Podilymbus podiceps. 



A few winter on Okanagan Lake. 

 Loon Gavia imber. 



A few winter on Okanagan Lake. 

 Red-throated Loon Gavia stellata. 



A juvenal female picked up on the shore of Okanagan Lake, 

 November 22nd, 1915. Small Loons observed on several occasions 

 were probably of this species. 

 Herring Gull Lams argentatus. 



Common winter resident. 

 California Gull Larus californicus. 



Not as common as the former. 

 Mergansers Mergus americanus. 



Common resident. 

 Red-breasted Merganser Mergus serrator. 



Regular winter resident. 

 Mallard A nas platyrhynchos. 



The bulk of the surface feeding ducks, leave in November, when 

 the small lakes and sloughs freeze over. A few remain as long as there 

 are open stretches of water in the streams but become quite poor. 

 Frequently mixed flocks of Mallard, Pintail, etc., are seen picking up 

 the weeds that have become dislodged by the wind and have drifted 

 on to the ice on the shore of the lake. 

 Gadwall Chaulelasmus streperus. 



No winter records since January 1912. 

 Baldpate Mareca americana. 



A few remain all winter and live parasitically on the Redheads, 

 snatching the weeds from their bills as they rise to the surface. They 

 are in constant motion, when feeding, dashing at every duck that rises 

 near them. 

 Green-winged Teal Nettion carolinense. 



A few winter. 

 Pintail Dafila acuta. 



A few winter. 

 Redhead Marila americana. 



The commonest duck on Okanagan Lake in winter. Late in 

 January, when their feeding grounds at the south end of the lake 

 become frozen, they congregate in enormous flocks in the vicinity of 

 Okanagan Landing. The prevailing winds are southerly and serve to 

 keep the shallow water here free of ice. Several specimens of pond- 

 weeds (Potamogeton) afford an abundant food supply. By February 

 15, the flocks have reached their maximum and number several 

 thousand. They remain in these large bands until March, when they 



