Copper Deficiency in Tule Elk at Point Reyes, California

Tule elk (Cervus elaphus nannodes) reintroduced to Point Reyes, Calif., in 1978 exhibited gross signs of copper deficiency by June 1979. Copper levels in liver (x̄ = 5.9 ppm) and serum (0.42 ppm) of elk at Point Reyes were below levels in adult tule elk from other locations in California (liver, x̄ ≥ 80 ppm; serum, x̄ ≥ 1.4 ppm). These levels were consistent with documented copper deficiency in wild and domestic ruminants. Copper serum levels increased in response to copper enriched dietary supplements and declined after the elk stopped eating the supplements. Analysis of plant and soil samples showed both are deficient in copper and normal in molybdenum and sulfur-sulfates. Deficiency in plants and soils at Point Reyes are probably due to low copper levels in the underlying granitic parent material.