habiting the study area, the bald eagle, osprey, and harlequin duck are most 

 vulnerable to mortality-induced population declines. 



The work force would peak at about 500 construction workers for a period 

 of about 20 months during this project (NLI 1978). Of these 500 workers, 200 

 would be hired locally and 300 would move into the area. Many of the latter 

 would bring their families to the area. The presence of this many people in 

 the project area increases the likelihood of illegal off-hours shooting of 

 wildlife, both on-site and off-site. The magnitude of this man-caused mortal- 

 ity is impossible to predict, but such shooting could nonetheless result in a 

 significant impact, especially in the case of the bald eagle. Local harvest 

 of game animals, both legal and illegal, would probably increase during cons- 

 truction. In recent years, five bighorn sheep ram permits have been issued 

 annually for the Kootenai River herd located near the project area; poaching 

 by construction workers could limit the number of permits which could be issued 

 in future years, thereby limiting hunter opportunities. The impacts of illegal 

 shooting can be mitigated somewhat by strict enforcement of regulations in the 

 project area, by posting notices near construction areas, or by closing the 

 area to hunting of bighorns. 



The possibil ity exists for entrainment of waterfowl and other water birds 

 in the intake structure; should this occur, it is unlikely that populations 

 will be significantly affected by the resultant mortality. 



Project construction could decrease natality rates by (1) destroying 

 nests during clearing, thus inhibiting or halting reproductive activities; (2) 

 displacing bighorn sheep during lambing (in late May or early June); or (3) 

 producing physiological stress as described elsewhere in this report. As 

 discussed earlier, the project could increase nest success of birds nesting 

 along the dewatered section. (^Such changes in natality are not expected to 

 significantly affect populations of species found in the project area.) 



PHYSIOLOGICAL STRESS 



The effects of stress are sublethal, difficult to identify, and may not 

 result in immediate observable population changes. Stress on a population 

 may increase as a result of displacement, which can indirectly affect mortality 

 and natality rates. For example, repeated displacement of bighorn sheep from 

 winter-spring range into areas of deep snow or other suboptimal habitat would 

 not kill animals directly, but it could cause abortion of fetuses or predispose 

 animals to mortality through other causes, such as predation, disease, starva- 

 tion, or hypothermia. Even slight increases in stress and the expenditure of 

 stored energy (such as would result from displacement and harassment) are im- 

 portant during winter, when most animals are already under severe stress. 



Creation of dust during construction could create slight increases in 

 stress by coating forage, irritating eyes, or impairing visibility, but rain- 

 fall is generally high in this area and dust is expected to have little or no 

 effect on wildlife. 



Mitigation of displacement-related stress to bighorn sheep or bald eagles 

 could be accomplished by restricting noise-producing construction activities 

 during late winter and spring. 



101 



