Assessment of Chukar and Gray Partridge Populations - Idaho Power

Hells Canyon Chukar and Gray Partridge Report, Ratti and Giudice 7ASSESSMENT OF CHUKAR AND GRAY PARTRIDGE POPULATIONSAND HABITAT IN HELLS CANYON1. IntroductionIn June 1999, Dr. John Ratti (Department of Fish and Wildlife Resources, University ofIdaho) responded to a request for proposal from Idaho Power Company to conduct an“Assessment of Chukar and Gray Partridge Populations and Habitat in Hell Canyon.” InSeptember 1999 a contract was signed between the University of Idaho and Idaho PowerCompany for this assessment to be conducted by Dr. Ratti. Project completion (i.e., draft reportdue) was scheduled for 1 April 2001. Author resumes are in Appendix A.Objectives of the study were to conduct a review and evaluation of chukar (Alectorischukar) and gray partridge (Perdix perdix) populations and habitat in Hells Canyon to: 1)characterize the social and ecological significance, 2) describe natural- and life-historyrequirements, 3) assess the current status of populations and habitat quality, 4) identify therelative significance of natural and anthropogenic limiting factors as they currently affect habitatquality and population stability, 5) project how habitat quality and population stability maychange in the future, and 6) suggest opportunities for mitigating limiting factors in order tobenefit these 2 species in the evaluation area.2. Study AreaThis review focused on the area surrounding the 3-dam complex and correspondingreservoir system that comprises Idaho Power Company’s Hells Canyon Hydroelectric Complex.Longitudinally, the evaluation area extends north from approximately Weiser, Idaho at river mile351 on the Snake River to Hells Canyon Dam at river mile 247 (Figure 1). Laterally, theevaluation area extended from the canyon rim in Oregon to the rim in Idaho (Figure 1). Thisarea encompasses approximately 1,600 km 2 .3.1. Literature Review3. MethodsWe attempted to locate all literature associated with the biology and ecology of chukarand gray partridge in North America, with emphasis on Hells Canyon and the IntermountainWest. Our search for literature included: 1) computerized literature-search services, 2) use of theUniversity of Idaho special-documents library (e.g., government reports), 3) personal contactswith state and federal biologists with experience or responsibility in or adjacent to Hells Canyon,and 4) review of literature cited in key publications on the target species.