lo University of Michigan 



In many places the streams are undercutting their banks, 

 leaving a nearly vertical exposure of earth and sometimes gravel. 

 The exposure of cut bank is usually from ten to fifteen feet in 

 height, but where the stream is cutting against a hill it may be much 

 higher. 



The soft dirt banks are the nesting-places of several species of 

 birds, and the burrows of a few mammals are found here also. 



CliJ' habitat and association: 



Aquila ckrysa'elos. Golden eagle. Summer, breeding (Osgood, Black- 

 welder). 



Falco peregrhms anatum. Duck hawk. Summer, breeding. 



Falco columbaritis columharius. Pigeon hawk. Summer. 



Sayornis sayus. Say phoebe. Summer (Osgood). 



Corinis corax principalis. Northern raven. Summer, breeding (Osgood). 



Petrochelidon lunifrons lunifrons. Cliff swallow. Summer (Blackwelder) . 



Tachycineta thalassina lepida. Northern violet-green swallow. Summer, 

 breeding (Osgood, Blackwelder). 



Rocky cliffs occur frequently along the larger rivers, especially 

 where these wash against the base of a hill or mountain. Cliffs 

 are also found sparingly in the higher parts of the hills and in a few 

 places in the lowlands, notably where an outcrop of harder rock 

 occurs. These cliffs are usually exposures of bare rock, somewhat 

 broken into ledges and sometimes with little gullies coming part 

 way down. A few herbs, shrubs, and small trees may, in the low- 

 lands, grow on the ledges and in the gullies. 



The clififs are the nesting-places of a number of birds, but no 

 trapping was done in the habitat and I have no records for 

 mammals. 



Equisetum habitat and association: 



Anas platyrhyiwhas. Mallard. Summer. 



Nettion carolinense. Green-winged teal. Summer. 



Dafila acuta tzitzihoa. Pintail. Summer. 



Anser albifrons gambeli. White-fronted goose. Summer. 



Biiteo lagopus sancti-johannis. Rough-legged hawk. Summer. 



Synaptomys dalli. Dall lemming-vole. 



Evotomys dawsoni dawsoni. Dawson red-backed vole. 



