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within the potential impact area. There are indications that this species has been declining in <br />numbers over much of its range. Some have attributed this decline to the hawks' intolerance of <br />human activity in and around nesting areas. Though the mining and disposal operations are not <br />proposed to seriously impact the critical nesting habitat of the ferruginous hawks, the increased <br />activity will likely cause them to move away from the perturbation source and hence the projected <br />perturbation value 5. The disposal area will also impact their hunting territory but since their hunting <br />territory is 60 square miles and the area is not saturated with ferruginous hawks, the few acres <br />projected for loss at any given time will be insignificant. <br />Golden eagles are common throughout their range in the western United States and are estimated <br />at 3.84 individuals per square mile in the area of proposed impact. Although they range over a <br />variable habitat territory of approximately 100 square miles, they prefer to nest in rocky cliff areas. If <br />golden eagles were highly susceptible to disturbance, the planned activities would pose problems at <br />the portal site. The portal is located in close proximity to the golden eagles. There are three known <br />nest sites active on the cliffs east of the portal, but it is likely that only one is used during any given <br />year as evidenced in 1979. The eagles select their nest site in the spring of a given year and use it <br />until fledging. At this time they hunt freely over their range using a variety of habitats and perches <br />and have little specific habitat requirements until the subsequent nesting season when they often <br />return to the same area where they successfully nested or were fledged. <br />The adaptive nature of golden eagles plus, the abundance of favorable habitat in both the proposed <br />impact and adjacent areas for hunting, nesting and perching allows for a perturbation rating of 2. No <br />surface vents were constructed within 1/4 -mile of the nesting sites on the cliffs above the proposed <br />portal. Further protection will be given to golden eagles by providing a buffer zone along Scullion <br />Gulch. No activity will be allowed from March 1 until June 1 in the following areas: Section 3: S -1/2 <br />SE -1/4, E -1/2 SE -1/4 SW -1/4 and Section 10: NE -1/4 NE -1/4 of T2N, R101 W. <br />Sage grouse are ubiquitous in open, semi -desert sagebrush and grass habitat throughout the <br />western United States. Sagebrush and grass are relied upon for food, cover and nesting. Mating <br />occurs in "leks ", open areas used in strutting displays in the spring. In this specific instance sage <br />grouse were concentrated 1 -2 birds per hectare, along the riparian habitat of the mine and water <br />takeout and in the grass habitats of the waste disposal site. Little preference was shown for <br />sagebrush and minimal for mixed desert shrub. The birds were nesting and feeding in the grass <br />areas of the waste disposal site. <br />Sage grouse are major inhabitants of, and dependent upon, open semi - desert sagebrush and grass <br />habitat throughout the western United States (Patterson 1952, Johnsgard 1973). Sagebrush and <br />grass are relied upon for food, cover and nesting (Dalke et al. 1963, Braun et al. 1977). Mating <br />occurs on "leks ", open areas used for male territorial defense and female strutting displays, in the <br />spring (Scott 1942). Knowing this, the terrestrial vertebrate consultant attempted field studies during <br />Minor Revision #147 (05/2011) IV -4 7 <br />