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7 * V* 



THE OTTAWA NATURALIST 



Vol. XXXI. NOVEMBER, 1917. No. 8. 



NOTES ON THE WINTER BIRDS OF THE 

 OKANAGAN VALLEY. 



By T A. Munro. 



In comparison with eastern Canada, the winter season of the 

 Okanagan Valley is mild, with a lighter snowfall and a greater 

 number of clear sunny days. In normal years the first cold weather 

 comes towards the end of November. Between November and the 

 first of March there arc usually three or four cold snaps, when the 

 temperature drops tc ten or fifteen below zero. By the end of 

 February the snow has melted and warm sunny days are the rule. 



During the severe winter of 1915-16, zero weather lasted almost 

 continuously from January 9th until February 4th. There was an 

 unusually large amount of snow and Okanagan Lake was frozen over. 

 The lowest temperature at Okanagan Landing was 24 below zero. 



Along the lake shore and in the river bottoms various wild fruits, 

 such as snowberry and rose hips insure an abundant food supply. 

 The fruit of the Black Haw (Crataegus douglasi) usually dm - on the 

 bushes and is greedily eaten by Bohemian Waxwings and Pine Gros- 

 beaks. Introduced weeds are well represented along roadsides and on 

 waste ground. Amaranthus retroflexus, Chenopodium album and 

 Melilotus alba are the commonest and the seeds form the staple diet 

 of Sparrows, Redpolls and Juncoes. 



The following notes cover the period between 1911 and 1917, 

 inclusive. 

 Western Grebe JEchmo phorus occidentalis. 



A few winter on Okanagan Lake. 

 Holboell's Grebe Colymbus holboellii. 



A few winter on Okanagan Lake. Both this species and the 

 former, die in large numbers every fall. Specimens examined were in 

 an emaciated condition and contained several species of parasitic 

 nematodes. In several cases a mass of wire-like parasites, clustered 

 between the leg muscles and the skin, caused the knee joints to swell 

 to twice the normal size. A segmented tape-worm was present in 

 several specimens. 



