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<br />INTRODUCTION <br /> <br />The Arizona Game and Fish Department (AGFD), acting as the non- <br />federal representative for Grand Canyon National Park, has prepared <br />the following Biological Evaluation (BE) for the U. S. Fish and <br />Wildlife Service (USFWS) in compliance with section 7 consultation <br />requirements of the Endangered Species Act (ESA). <br /> <br />CHAPTER I <br /> <br />A. BACKGROUND <br /> <br />The Kanab ambersnail (KAS; Succineidae Oxyloma haydeni kanabensis <br />Pilsbry, 1948) is a federally endangered landsnail that was <br />proposed for emergency listing in 1991 (USFWS 1991) and formally <br />listed in 1992 (USFWS 1992). KAS is also recognized by the Arizona <br />Game and Fish Department in the draft Wildlife of Special Concern <br />in Arizona (WSCA; AGFD in prep.). This rare, endemic landsnail is <br />restricted to permanently wet areas within small wetlands of the <br />Colorado Plateau (USFWS 1995). Currently, only two populations of <br />this succineid snail are known to exist in the American Southwest: <br />one at Three Lakes (3L), a private marsh near Kanab, Utah, and the <br />other at Vaseys Paradise (VP), a spring within the Grand Canyon of <br />Arizona. Threats to KAS include loss and/or adverse modification <br />of wetland habitat, which is scarce in this semi-arid region (USFWS <br />1995). The USFWS has established the recovery priority of this <br />subspecies as 6C, i.e., a subspecies with a high degree of threat <br />and a low recovery potential with a possibility of conflict with <br />human activities (USFWS 1995). <br /> <br />B. OCCURRENCE HISTORY <br /> <br />This rare landsnail was first discovered in 1909 by Ferriss at ~the <br />Greens" in Kanab Creek Canyon, approximately 10 kID north of Kanab, <br />Utah (Ferriss 1910), and later identified by H.A. Pilsbry (1948). <br />The site was originally a seep-fed marsh containing mosses and <br />cypripediuros (orchids) located near the main channel of the creek <br />(Ferriss 1910). Dewatering in the last decade has caused periods of <br />desiccation at this site and has currently reduced the habitat to <br />a wet ledge about 15 em wide and 46 m long (USFWS 1992). Since <br />September 1990, no live KASs have been found at this location, and <br />the population is believed to be extirpated (USFWS 1995). <br /> <br />A second, larger KAS population exists 2.1 km distant at Three <br />Lakes (3L), a privately-owned wet meadow 10 km northwest of Kanab, <br />Utah (Spamer and Bogan 1993, USFWS 1995). The 3L habitat is <br />characterized by cattail (Typha domingensis) marshes and sedge <br />(Juncus spp.) meadows. Kanab ambersnails are most abundant under <br />fallen cattail stalks found at the edge of cattail stands and in <br />sedge meadows (USFWS 1995). Cattails and dense sedge and grass <br />