12—Cold Mountain Cold Rivers Complaint

Appendix A p.14. The BA also states that “[I]n Montana, egg

laying occurs as early as February 7 or as late as Mid-

April. . . . Hatching occurs from mid-March to mid-May. . .

.”Clearly, then, these are the critical times of year for

nest reproduction. The BA further states that::

[sounds] that are sporadic and observable may affect
bald eagle nesting and perching behavior more than
constant predictable sounds produced by activities
that can not be observed. . . . Although snowmobiles
are generally a moving activity, sound levels
associated with motion may cause these activities to
impact bald eagle behavior more than most other types
of human activities.

Id., Appendix A, p. 14. Again, there is no analysis of

helicopters in the BA. However, if snowmobiles would have

the above-described effect on bald eagles, one can easily

extrapolate that helicopter activities would have

exponentially greater impacts on eagles. This is especially

true in view of the fact that eagles tend to nest in the

tallest tree stands, and prefer secure perching areas to

forage along the open waters of the Madison River and

Hebgen Lake where helicopters would be particularly

disturbing. Id.Appendix A, p.13. Significantly, the BA

notes that bald eagles extensively use the north side of

the Madison Arm of Hebgen Lake for perching, foraging and

loafing, and that once the ice melts and eagles can no

longer perch on the ice, then “tree perches along the edge