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<br />Arizona Game and Fish Department <br />NGTR 125: Kanab Ambersnail Report <br /> <br />April 1998 <br />Page 2 <br /> <br />The USFWS 1994 Biological Opinion on the operation of Glen Canyon Dam required that the VP <br />KAS population and habitat be quantified. An interagency team of researchers began ecological <br />studies on KAS at VP in 1995 and have continued monitoring through 1997. Participating agencies <br />and institutions ofKAS monitoring include: AGFD, USFWS, National Park Service (NPS), U.S. <br />Bureau ofRec1amation (USBR), Grand Canyon Monitoring and Research Center (GCMRC), and <br />Northern Arizona University (NAU). USBR, USFWS, and the Central Utah Project Completion <br />Act office (CUPCA) provided funding for AGFD to conduct KAS habitat surveys in Grand <br />Canyon and northern Arizona. CUPCA has entered into a cooperative agreement with AGFD to <br />implement KAS n:covery efforts in Arizona. 'The establishment of additional wild populations of <br />KAS will undergo AGFD's 12-step reintroduction process (AGFD 1987). In addition, recovery <br />efforts will include the establishment of a KAS refugium at 'The Phoenix Zoo (TPZ) to maintain <br />a supplemental genetic source. 'This report is provided as a contract obligation to the USBR for <br />partial funding of AGFD Kanab ambersnail studies between July and November 1997. Further <br />infonnation on AGFD habitat surveys and evaluation prior to this time period are documented in <br />Sorensen and Kubly (1997). <br /> <br />METHODS <br /> <br />STUDY AlulA <br />In this report, site locations along the Colorado River corridor of Grand Canyon follow historical <br />convention of recording river distances as miles downstream of Lee's Ferry with metric <br />conversions in parentheses. River right (RR) and river left (RL) describe which side of the river <br />when facing downstream. River mileage, elevations, site names, drainages, and geologic strata <br />were obtained from regional guidebooks (Kelsey 19&7, 1995; Stevens 19&3), published and <br />government documents (Spamer and Bogan 1993; Stevens et al. 1997b), and U.S. Geological <br />Survey 7.5 minute series topographical maps. <br /> <br />MONITOllINO <br />Stevens et aI. (1997a, 1997b) provided detailed methodology for KAS monitoring at VP. <br />Vegetation patches were mapped from topographic surveys using total station instruments, <br />electronic data recorders, and USBR's STARS model (Randle and Pemberton 1988), a stage-to- <br />discharge hydraulic model used to estimate flow elevations. Oblique photogrammetry was used <br />to determine areal extent of inaccessible, upper zone vegetation at VP. High-angle photographs <br />of VP were tala:n in November 1994, March, April, and November 1996, and Match 1997 from <br />the upper plateau opposite of VP. Population estimates of KAS were determined from replicate <br />2<k:m-diameter sample plots and bootstrapping statistical methods (Stevens et al. 1997a). <br />Microhabitat attributes (e.g., substrate type, depth and moisture of substrate and litter/duff, plant <br />cover/density, vegetation composition and height, percent live/dead vegetation, and distance to <br />patch edge) were recorded for each sample plot. Live-trapping of deer mice (Peromyscus spp.) <br />was done to estimate densities of potential KAS predators at VP. Incidence of KAS parasitism by <br />