Endangered and Threatened Wildlife and Plants; Determination of Endangered Status for Three Wetland Species Found in Southern Arizona and Northern Sonora, Mexico

The Fish and Wildlife Service (Service) determines endangered status for the Canelo Hills ladies-tresses (Spiranthes delitescens), the Huachuca water umbel (Lilaeopsis schaffneriana ssp. recurva), and the Sonora tiger salamander (Ambystoma tigrinum stebbinsi) pursuant to the Endangered Species Act (Act) of 1973, as amended (16 U.S.C. 1531 et seq.). These species occur in a limited number of wetland habitats in southern Arizona and northern Sonora, Mexico. They are threatened by one or more of the following--collecting, disease, predation, competition with nonnative species, and degradation and destruction of habitat resulting from livestock overgrazing, water diversions, dredging, and groundwater pumping. All three taxa also are threatened with extirpations or extinction from naturally occurring climatic and other environmental events, such as catastrophic floods and drought, a threat that is exacerbated by habitat alteration and small numbers of populations or individuals. This rule implements Federal protection provided by the Act for these three taxa.