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Kent A. Gorham <br />Page Five <br />February 1, 1993 <br />deer is because of the limited amount of time they have spent on <br />site and because they are present for inspection during mid-day <br />when most animals are bedded and therefore not readily visible. <br />Raptors <br />Raptors have not been studied at the mine site to the extent that <br />elk have. Therefore CYCC does not have quantitative data regarding <br />habitat utilization. However, reproductive success has been <br />monitored on a couple of key species. In addition, there is some <br />long term information on the number of nesting pairs for several <br />key species. I believe it is reasonable to assume that, if the key <br />species identified in the premine studies as of concern are still <br />as abundant and as successfully reproducing presently then the <br />current reclamation is as valuable to them as the premine <br />vegetation. <br />Three pairs of nesting Golden Eagles were identified during <br />baseline studies in the mine permit area. All three eyries <br />continue to be active. Two of the eyries are within 1000 ft. of <br />reclamation. Seven years (1979 - 1986) of nest success monitoring <br />shows no decrease in reproductive success (see Technical Revision <br />#9, Permit C-81-07 approved April 30, 1987). In fact the long term <br />reproductive success (X = 1.42 eaglets fledged/yr/nest) is very <br />high. Many Golden Eagles do not breed every year and apparently <br />nest only every other year in the Western U.S. In addition the <br />older eaglet often kills the younger so normally only one eaglet <br />fledges. (See the Audubon Society Encyclopedia of North American <br />Birds by John K. Terres). The complete reason for these three <br />eyries high reproductive success is not known. However, it is <br />indicative of a consistently high prey base upon which they can <br />depend. Mike Lockhart (USFWS) commented on this high reproductive <br />success during a year when he was aware of poor nesting success on <br />many Golden Eagle eyries in Colorado and surrounding states. He <br />attributed poor nest success in these other areas to low rabbit <br />populations (primary prey of many Golden Eagles). Observations at <br />this time of the eyries on the mine revealed the remains of <br />marmots. It was obvious that these eagles were not completely <br />dependent on rabbits, and had a sufficiently high alternate prey <br />base. Although the number of marmots on the reclamation have not <br />been quantified they are very high compared to undisturbed sites. <br />If the Division doubts these observations CYCC recommends the <br />Division discuss it with professional biologists familiar with the <br />area and the habitat requirements of marmots. CYCC stopped <br />installing rock piles because there are too many marmots. Some of <br />the older reclamation is ideal for marmots. In fact they have been <br />so high some years that they have damaged some mine facilities by <br />chewing holes in buildings and wiring on equipment. Attempts have <br />been made a couple times, via trapping and shooting, to control <br />their numbers, however with very limited success. Therefore, it is <br />not unreasonable to assume that the reclamation makes significant <br />contribution to the prey base of these Golden Eagles. Observations <br />of Golden Eagle hunting habits on the mine reveals that they do not <br />