mtix»'«:!^MSM 



Figure 79. Vegetated organic mats that were washed down- 

 stream and grounded during high water on Too I i k River 

 floodplain gravel bars. 



type, habitat preferences, and home range size. Most responses were directly 

 related to the removal of floodplain vegetation. A response was recorded at 



19 of the 25 study sites (Table 28). In all cases where no differences in 

 populations (particularly birds and small mammals) were recorded, vegetation 

 was either not removed (Kuparuk, Ivishak, and Shaviovik Rivers and Phelan 

 Creek) or only very sparse vegetative cover was removed (Ugnuravik River and 

 Middle Fork Koyukuk River-Downstream). 



At those sites where significant quantities of floodplain vegetation 

 were removed, faunal responses basically consisted of four different 

 react i ons : 



• Population Reductions - passerines and small mammals responded to 

 the loss of vegetative habitats. 



• Population Increases - water birds and ground squirrels responded to 

 the removal of heavy vegetative cover, and, in the case of ground 

 squirrels, also to the presence of overburden piles. 



249 



