the Libby Dam compensation effort, and a greater opportunity for enhancement 

 through habitat acquisition might exist outside the Libby-Troy area. Enhance- 

 ment management of existing MDFWP lands would probably be more cost-effective. 

 (NOTE: Control of shrub invasion of riparian grasslands used by biah^rn sheep 

 has been discussed previously as a mitigating measure). 



Harlequin Duck Habitat Enhancement . Little opportunity exists for com- 

 pensation of harlequin duck habitat losses. It is reasonable to assume that 

 all suitable habitat in the vicinity is occupied, and that any habitat changes 

 of such areas would only be detrimental to populations. Investigation of the 

 Yaak Falls as possible compensation habitat is recommended as part of the 

 monitoring program presented below. 



Enhancement of Habitat of Other Waterfowl . Nesting habitat of Canada 

 geese and cavity-nesting ducks could possibly be enhanced along the Kootenai 

 River by installation and maintenance of nest boxes, nesting platfonns and/or 

 nesting islands. However, as discussed by Nelson et aj^. (1978), such increases 

 in nest site availability are effective only where nest sites are limiting and 

 where habitat is otherwise suitable to support a larger population. There is 

 some evidence that breeding populations in the Kootenai Falls ared are limited 

 by the availability of brood-rearing habitat and food for young ducks (espe- 

 cially aquatic macroinvertebrates) rather than by nest site availability, and 

 new nesting structures would probably provide but minor increases in an already 

 minor production, unless impoundment were to substantially increase availability 

 of food along the shoreline. Use of the area by migrating field-feeding water- 

 fowl could possibly be enhanced by creation of grainfields adjacent to the river 

 but suitable areas are lacking and cost-effectiveness would probably not be 

 great enough to justify such land use change. Creation of shallow permanent 

 pools along the shoreline using sandbags or dikes has been discussed previously. 



Installation of Raptor Nest Structures . As was the case with waterfowl, 

 breeding populations of osprey, bald eagle, and red-tailed hawks in the area 

 appear to be limited by factors other than nest-site availability (probably 

 food availability and relative security). An abundance of potential nest 

 sites presently exist in the area, and creation of new sites would pro- 

 bably do little to increase nesting populations or production of young. 



Compensation by Protection of Threatened Habitat 



Another strategy for compensating unmitigated losses is to prevent future 

 impact, which would otherwise occur, by protecting threatened habitat off-site. 



The rate of loss of quality wildlife habitat due to development is in- 

 creasing nationwide, and the loss of riparian habitat is especially acute, with 

 annual losses approaching 6 percent (McCormick 1968). Nearly all habitat 

 presently available can be considered threatened or endangered ove.- the long- 

 term, as man's exploitation of other resources continues (Mustard 1978). Long- 

 term protection of habitat, then, can provide substantial future benefits, 

 benefits which may actually increase in unit value over time. 



Protection of habitat can be afforded via fee simple purchase, which is 

 often prohibitively expensive, or via long-term dedication or easement. The 

 legal framework for the latter is provided at the state level by the Montana 

 Open Space Land and Conservation Act of 1975, which provides for maintenance 



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