WestLand Resources, Inc. (WestLand) was retained by Rosemont Copper Company (Rosemont) to prepare a series of technical memorandums to supplement the Biological Assessment for the Rosemont Copper Project (the Project). The Draft Environmental Impact Statement (DEIS) for the Project (USDS 2011) summarized the potential effects of light, based largely on the initial lighting plan for the Project (M3 2009), on biological resources, including endangered species and critical habitat. Since the publication of the DEIS, Rosemont has proposed to modify their lighting program to avoid and minimize the extent and effect of light on the night sky and more specifically on listed species and critical habitat. The specific conservation measures proposed as outlined by Monrad (2012) are:
- Employ 21st century lighting sources that operate well under dimmed conditions and can be adaptively controlled to reduce the amount of light emitted,
- Employ shielded lighting sources to reduce the amount of uplight emitted,
- Use lighting sources or filters to eliminate certain wavelengths of light (less than 500 nm) that attract wildlife,
- Use the smallest necessary light source for applications to reduce the amount of light emitted, and
- Employ lighting on mobile equipment to reduce stray light.
This memorandum analyzes the potential effects of the proposed lighting conservation measures for the Project on the following endangered species and critical habitat: Chiricahua leopard frog (Lithobates chiricahuensis) and its critical habitat, lesser long-nosed bat (Leptonycteris yerbabuenae), jaguar (Panthera onca) and its proposed critical habitat, and ocelot (Leopardus pardalis). We begin with a brief discussion of the lighting plan to be implemented by Rosemont. We then perform an analysis of the geographic extent of the potential effects of lighting from the Project, provide an estimate of the degree of skyglow expected from the Project, and discuss how the proposed lighting conservation measures could affect endangered species and critical habitat.
WestLand Resources Inc. 2012i. Rosemont Copper Project: Potential Effects of Lighting Associated with the Rosemont Project on Endangered Species. Project No. 1049.21. Prepared for Rosemont Copper Company. Tucson, AZ: WestLand Resources, Inc. December 7.