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Black-footed Fertet Report Dowe Flats Project
<br />' The Dowe Flats nocturnal survey area, therefore, included all 385 acres of impact area over
<br />the 25 year life of the mine and a surrounding 0.5 mile buffer zone, rather than only the
<br />initial mine development area and surrounding buffer zone. The survey area extended
<br />beyond the 0.5 mile buffer zone to the southeast, southwest, and north, to the edges and(or
<br />' bottlenecks of the prairie dog distribution in Dowe Flats. Although the prairie dog
<br />distribution covered 1,041 acres on May 23, 1994, the town was in the midst of a plague
<br />' epizootic that had already reduced prairie dog distribution 171.0 acres from 1,212.0 acres
<br />mapped on April 1, 1994. Nevertheless, survey coverage was oriented to the April 1
<br />' distribution. This distribution was divided into approximate thirds, with each area surveyed
<br />by 2 individuals (a crew) in a vehicle and(or on foot over 3 consecutive nights. Thus, a total
<br />of 18 person-nights were required to cover the entire survey area.
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<br />Survey personnel were fairly experienced; 4 of the 6 people had prior ferret survey
<br />' experience (Appendices 9.1 and 9.2). Thompson, a certified ferret surveyor (October 2,
<br />1985), functioned as survey leader and Crew 1 leader. Holst, a professional wildlife biologist
<br />with previous nocturnal ferret survey experience, was Crew 2 leader. Figgs, a professional
<br />resource planner, with previous ferret survey experience, was Crew 3 leader. Crew
<br />personnel included 2 veterinary students (Spidle and Tasse), and Lederer, a professional
<br />t biologist with The Nature Conservancy who had previous ferret survey experience.
<br />Approximately 1 week prior to the surveys, all survey personnel received copies of Clark et
<br />,' al. (1983) and USFWS (1989) and were paid to review them. Before surveys on August 7,
<br />Thompson gave a 1-hour lecture to all survey personnel, addressing site orientation, the
<br />' mine proposal, ferret life history information, survey procedures, what to do if a ferret is
<br />spotted, plague, safety, and public relations (Appendix 9.3).
<br />' Surveys were conducted from dusk until dawn, systematically covering all prairie dog towns
<br />in Dowe Flats in search of ferrets and their eyeshine. At least 3 complete replications of
<br />' each of the 3 survey areas was conducted each night. Each crew member used a 300,000
<br />(n=2), 400,000 (n=2), or 1,000,000 (n=2) candlepower spotlight connected to a backpack-
<br />' mounted deep cycle battery (pedestrian surveys) or to a vehicle's cigarette lighter. During
<br />pedestrian surveys, crew members walked < 100m apart, depending on the width of the
<br />habitat and the number of passes required, slowly sweeping their spotlight approximately
<br />180° in front of them and to the side opposite the other crew member. In tall vegetation
<br />(infrequently encountered) or where obscured by topography, transect separation was
<br />reduced. For vehicular coverage, the crew drove slowly down marked routes searching 360°
<br />around them with spotlights. One member of each vehicular crew stood in the bed of a
<br />' pickup truck or sat in the passenger window. Areas beyond the spotlight's areas of
<br />illumination (150-200m), and/or areas obscured by tall vegetation or topography, were
<br />' Western Ecosystems, Inc. 7 November, 1994
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