1921 BIRDS OF MONTANA 17 



whieli ai-p less thau a hundred feet across. They are only found in the moun- 

 tainous parts of the state, and are more abundant in the northwestern part of it, 

 particularly in the Glacier Park, where there are said to be at lease two hundred 

 and fifty. As in the ease of prairie lakes, the bird life of these lakes is veiy valu- 

 able. One species, the Spotted Sandpiper, is eliaracteristic of their shores, and 

 may be practically always found about them. Other species are local, siu'li as 

 ducks (particularly tree nesting species, like the mergansers, golden-eyes and 

 Buffle-head), the Canada Goose, Osprey, Kingfisher and Tree Swallow. 



Rivers (see fig. 3) flow mainly through the prairie region and tlie moun- 

 tain valleys. They are much varied in character, and might pi-rhaps hv divided 

 into several stream-border associations, according to whether tlieir banks were 

 bordered by grass-meadows, cottonwood groves, or rocky cliffs. The birds breed- 



Fig. 3. View on the Tetox Rivek, neai: Di ..■ . . i, • ' ■" M^mana. 



Grass-covered bench-lands in the foreground and in the uisia.nce, and 

 cottonwood groves bordering the niver. transition zone. plioto hy a. d. 

 DrBois. 



ing along these rivers vary, and, as in the case of mountain laki-s, the Spotted 

 Sandpiper is the only species tliat is entirely characteristic. Other species founil 

 more or less locally along rivers are the Great Blue Heron, Killdeer, Kingfisher, 

 Kingbird, and Bank Sw-allow. Where steep cliffs border the sides of rivers, 

 some species nest in the cliffs, but since their presence is due to the rocks rather 

 tlian the water, they should be considered as belonging to a rock association. 



Mountain streams (see fig. 4) are somewhat similar to rivers, except that 

 their current is swifter and that they contain frequent waterfalls and rapids. In 

 some places well within the mountains the streams often take on the quieter 

 character of rivers, and in such e;iscs the one characteristic bird of river bordei's 



