Elk and Deer Diets in a Coastal Prairie-Scrub Mosaic, California

Abstract

We examined the diets of reintroduced tule elk (Cervus elaphus nannodes Merriam) and resident Columbian black-tailed deer (Odocoileus hemionus columbianus Richardson) inhabiting the coastal prairie-scrub mosaic of Tomales Point, the northernmost portion of the Point Reyes Peninsula, Calif., during 1979-81. The elk diet differed between years whereas the deer diet did not. The pattern of seasonal quality of elk and deer diets, as measured by fecal nitrogen (FN) was similar between species and years. This was achieved although botanical composition differed between herbivores in some seasons. Dietary overlap was lowest in the wet winter months when fecal nitrogen was highest and vegetative standing crop was lowest. Conversely, dietary overlap was highest in the dry summer months when fecal nitrogen was lowest and vegetative standing crop highest. Both herbivore species showed selection and avoidance of certain plant species in June of both years. These findings are compared to other cervid-habitat systems.