° 1915 ] Cooke, Bird Migration in the Mackenzie Valley. 44 f 



well-watered forest — a genuine birds' paradise. Attracted by 

 the early season and abundant food supply, the birds turn north- 

 westward and settle for the summer in the valley of the Mackenzie. 



The thirty -three species that traverse this route are Sterna 

 hirundo, Micropalama himantopus, Limosa hcemastica, Numenius 

 borealis, Butco b. borealis, Sphyrapicus v. varius, Chordeiles v. virgini- 

 anus, Sayornis phoebe, Empidonax flaviventris, Empidonax trailli 

 alnorum, Otocoris alpestris hoyti, Cyanocitta c. cristata, Euphagus 

 carolinus, Carpodacus p. purpureas, Calcarius I. lapponicus, Passer- 

 herbulus n. nelsoni, Zonotrichia albicollis, Spizella m. monticola, 

 Melospiza m. melodia, Mclospiza georgiana, Passcrclla i. iliaca, 

 Zamelodia ludoviciana, Vireosylva philadelphica, Lanivirco s. soli- 

 tary us, Dendroiea tigrina, Dendroica magnolia, Dendroica castanea, 

 Dendroiea wrens, Dendroica p. pedmarum, Seiurus aurocapillus y 

 Wilsonia p. pusilla, Hyloeichla a. alieio?, and Hyloeichla guttata 

 pallets i. 



A modification of this route from the southeast in a still more 

 pronounced form is followed by the White-winged Scoter (Oidemia 

 eleglandi), which winters off the coast from Massachusetts to New 

 Jersey and in its spring migration follows the valley of the Connecti- 

 cut, crosses to the Hudson, thence to the Great Lakes and north- 

 westward to its summer home in the Mackenzie Valley. It is 

 probable that this same general route is followed by many thousands 

 of the ducks of other species which winter so abundantly along the 

 coast from Chesapeake Bay to Florida, but it is also true that a 

 comparatively small part of these traverse this route as far as Great 

 Slave Lake, since the larger part stop for the summer in the " ducks' 

 paradise" of Manitoba and the Saskatchewan. 



Still another route, practically east and west instead of north and 

 south is followed by the three species of Jaeger, which winter on the 

 Atlantic, appear in Hudson Bay with the earliest open water and 

 then cross nearly due west to the breeding grounds about Great 

 Slave Lake, and to the northward. 



There are eighteen species that also probably use the main route 

 from the southeast but the proof of this use is not so simple, because 

 these species not only occur in the central Mississippi Valley, but 

 also range regularly across the plains to the foothills of the Rocky 

 Mountains. These eighteen species are: Grits americana, Pisobia 



