TRACY, C.R.; AVERILL-MURRAY, R.; BOARMAN, W.; DELEHANTY, D.; HEATON, J.; MCCOY, E.; MORAFKA, D.; NUSSEAR, K.; Univ. of Nevada, Reno; Arizona Game and Fish; U.S.G.S.; Idaho State Univ.; Univ. of Redlands; Univ. of So. Florida; California Acad. of Sci.; Univ. of Nevada, Reno: Scientific Assessment of the Desert Tortoise Recovery Plan

An eclectic committee of scientists has been empanelled to assess the scientific soundness of the Desert Tortoise Recovery Plan (USFWS 1994) in relation to contemporary scientific knowledge. A series of six workshops, conducted with a total of twelve additional invited scientists, have been conducted to review new analyses synthesizing the adequacies and inadequacies of the original recovery plan. The assessment committee has discovered continued decline of tortoise numbers in some prescribed Desert Wildlife Management Areas (DWMAs), and those declines have been so severe that they have created discontinuities in tortoise populations causing increased fragmentation and vulnerability to extirpation. In other DWMAs, tortoise population densities within protected habitats appear not to be declining although loss of habitat remains an issue rangewide. The causes of declines appear to be the collective effects of many, sometimes interacting, threats to persistence. The committee has assembled the scientific basis for designating distinct population segments, and the committee�s report will suggest new approaches to hypothesis-based monitoring of the efficacy of management actions. The report from the committee will become the scientific basis for a new recovery plan for this imperiled species.